Is Intermittent Fasting Good for Bulking & Building Muscle?
Intermittent fasting is popular for weight loss. But what if you’re a skinny guy trying to bulk up? Can you use intermittent fasting to build muscle faster or more leanly? After all, intermittent fasting raises growth hormone production, which purportedly helps with muscle growth; it increases insulin sensitivity, which could help make your muscle gains leaner; and research shows that intermittent fasting may help preserve muscle when losing weight.
On the other hand, bodybuilders are known for eating frequently—every few hours. They eat more often than the average person. Why is that? Could there be an advantage to eating more meals more often?
Finally, does intermittent fasting make it harder to eat enough calories to gain weight? Skinny guys are notorious for having smaller stomachs, faster metabolisms, and more meagre appetites, all of which can make it harder to eat enough calories to gain weight. Will intermittent fasting make that even harder?
- What Is Intermittent Fasting?
- How Does Intermittent Fasting Affect Our Health?
- How Does Intermittent Fasting Affect Muscle Growth?
- Does Intermittent Fasting Allow for Leaner Gains While Bulking?
- How Calorie Cycling Affects Muscle Growth
- How Much Fat Gain Is Normal While Bulking?
- Intermittent Fasting is Extreme Calorie Cycling
- How to Make Leaner Gains with Intermittent Fasting
- Using Intermittent Fasting for Cutting
- Calorie Cycling Isn’t Very Powerful
- Does Intermittent Fasting Allow for Leaner Muscle Growth?
- The Benefits of Eating More Frequently While Bulking
- Intermittent Fasting vs a Traditional Bulking Diet
- The Best Types of Intermittent Fasting for Muscle Gain
- New Intermittent Fasting Research
- 2020 Study on Intermittent Fasting for Muscle Gain
- 2020 Study on Protein Distribution for Muscle Growth
- 2020 Study on Intermittent Fasting for Cutting
- 2021 Meta-Analysis on Intermittent Fasting for Cutting
- 2022 Study on Intermittent Fasting & Muscle Growth
- A 2023 Meta-Analysis on Intermittent Fasting & Appetite
- 2024 Study on Protein Distribution
- 2024 Meta-Analysis on Intermittent Fasting for Weight Loss
- Summary
What Is Intermittent Fasting?
Intermittent fasting is an eating pattern that alternates between periods of fasting and feeding. That could mean fasting during the morning and eating in the afternoon. It could also mean eating one day and fasting the next. It also includes Ramadan.
Almost everyone alternates between fasting and feeding. Most of us fast between dinner and breakfast, often for around 8–12 hours. That’s a normal eating pattern. Intermittent fasting is when the fast is extended beyond that.
The most commonly recommended type of fasting is a 16-hour fast followed by an 8-hour feast. It’s called the “LeanGains” protocol, so you might imagine it’s designed for leanly building muscle. It isn’t. It’s designed for losing fat. We’ll get into muscle-building protocols soon, but let’s start at the beginning.
How Does Intermittent Fasting Affect Our Health?
Intermittent fasting has a few proven benefits. For example, four high-quality studies show that men produce more growth hormone when intermittent fasting (study, study, study, study). There are other potential advantages, too, such as having more energy in the morning, increased insulin sensitivity, and better cell repair.
Most of these health benefits are connected to the calorie deficit. Most people find that intermittent fasting reduces their appetite, causing them to eat less food. That’s why we see these same benefits when people try other low-calorie diets, such as ketogenic diets or plant-based diets. Most people are overweight, so eating less food improves several different health markers. On the other hand, if you’re naturally thin, you probably already have all of these advantages.
Furthermore, if intermittent fasting causes a skinny guy to lose weight or prevents him from building muscle, it could be bad for his health. We don’t benefit from losing weight, we benefit from gaining muscle. A diet that interferes with that could be bad for us.
How Does Intermittent Fasting Affect Muscle Growth?
People tend to eat less food while intermittent fasting. That’s great for losing weight, but it’s awful for gaining weight, bulking up, and building muscle. That’s especially true for skinny guys who are already struggling to maintain a healthy body weight.
But let’s ignore that disadvantage for a moment. For the sake of argument, let’s say that you’re able to get into a calorie surplus while intermittent fasting. If you can eat enough calories to gain weight, can intermittent fasting allow you to bulk up more leanly? Let’s take a deeper look.
Does Intermittent Fasting Allow for Leaner Gains While Bulking?
Intermittent fasting is an extreme example of calorie cycling. To understand how intermittent fasting affects fat storage and muscle growth, first, we need to understand how regular calorie cycling affects fat storage and muscle growth.
How Calorie Cycling Affects Muscle Growth
The first thing we need to do is distinguish between bulking and cutting. You can use calorie cycling to help with either goal, but the effects are rather different. When you’re bulking, you’re in a calorie surplus, and your body is totally primed for muscle growth, allowing you to build muscle quite rapidly.
While we’re bulking, we have a huge potential to build muscle. Let’s imagine it with a simplified graph like this, where the empty area under the dotted line is how much muscle your body is capable of building over time if you do everything perfectly:
As you can see, it’s not a flat line. Your body will be primed for muscle growth after a good workout, and then that muscle growth will gradually slow down as time passes, usually grinding to a halt within 48 hours.
The other thing to keep in mind is that any calories which cannot be invested in muscle growth will be stored as fat. This means that if you eat a large calorie surplus (blue line), you’re going to gain a maximal amount of muscle (red), but you’re also going to gain quite a lot of fat (yellow). This is called a “dreamer bulk,” and it looks like this:
Most people don’t want to gain that much fat, so they do what’s called a “lean bulk,” where they eat a smaller calorie surplus, like so:
By bringing down your calorie intake, you’re still gaining almost as much muscle, but you’ve slightly reduced the amount of fat that you’re gaining. However, this is a compromise. You’re not eating enough calories to fully maximize muscle growth after your workouts, and you’re also gaining some extra fat because you’re not tapering off your calorie intake as your muscle growth potential slows.
You might improve your gains by lining up your calorie intake with your muscle growth potential, eating extra calories in the meals following a workout, then easing back on the calorie surplus afterwards. Maybe. It makes sense in theory, but the evidence is still fairly weak. But for the sake of argument, let’s say we get some extra lean muscle growth:
Even if you’re calorie cycling, you still want to keep yourself in a consistent calorie surplus. You still want to be steadily building muscle all day long, all week long, and all month long.
How Much Fat Gain Is Normal While Bulking?
It’s common to gain at least a little fat while bulking. That doesn’t mean you’ll get fat, just that you’ll gain fat. Even in the leanest bulking transformations, there’s usually some fat being gained. That isn’t a bad thing. You might not even notice it.
Your body-fat percentage won’t necessarily increase, either. If you start bulking at 15% body fat, then so long as you’re gaining 85% muscle and 15% fat, your body fat percentage will remain at 15% as you continue gaining weight.
Your muscles are getting bigger, too, stretching your fat thinner and giving your body more structure. Even if you gain some extra fat, you might not lose any muscle definition. The fat may even help you look buffer and fuller.
If you’re gaining too much fat, reduce your calorie intake. Bulk more slowly. That will slow your rate of weight gain, leaving fewer surplus calories to spill over into fat gain. Instead of gaining one pound per week, gain 0.5 pounds per week. You might gain muscle slightly slower, but you’ll radically reduce the fat you gain.
Intermittent Fasting is Extreme Calorie Cycling
Intermittent fasting doubles down on calorie cycling. During the feeding windows, you have more than enough calories to build muscle at full speed, and during fasting periods, you’ll dip into a calorie deficit, losing fat. This creates the misconception that you can lose fat even while you’re bulking up.
The misconception comes from the fact that in order to gain weight, you need to be in an overall calorie surplus. That means during your feeding periods, you need to make up for all the calories you missed while fasting. When you try to catch up on those calories, some will spill over into fat storage. What happens is that you lose a bit of fat while fasting, then gain even more during the feeding window.
How to Make Leaner Gains with Intermittent Fasting
If you’re bulking very slowly, gaining just a pound or two each month, then your calorie surplus doesn’t need to be very high. In this case, with such a small overall surplus, you miss out on some of the extra testosterone, nutrients, and cellular signalling, so your growth potential slows down, like so:
You won’t be able to build muscle as quickly, but you may still prefer this approach. For example, if you’re a fitness model trying to maintain yearlong leanness, and you’re happy making very slow gains, you might prefer this method.
Guys like Martin Berkhan (LeanGains) and Gregory O’Gallagher (Kinobody) do a good job of this. They might be able to get results that look something like this:
However, to say that their programs are designed for this would be to sell them short. Even the LeanGains intermittent fasting protocol is designed for fat loss and muscle maintenance, not for bulking. To quote the guy who created it, Martin Berkhan:
The “gain” in Leangains can therefore be a bit misleading, as most of my clients wants to lose fat, while retaining as much muscle as possible in the process.
Martin Berkhan, creator of LeanGains
Using Intermittent Fasting for Cutting
If you combine hypertrophy training with a calorie deficit and a good cutting diet, you can lose fat while keeping most of your muscle. Some skinny-fat beginners are even able to gain muscle while losing fat. This is true whether you use intermittent fasting or not. The advantage of intermittent fasting is that it makes it easier and arguably more enjoyable to get into a calorie deficit.
Calorie Cycling Isn’t Very Powerful
Calorie cycling pales in comparison to the quality of your workouts, the quality of your diet, your overall calorie intake, your overall protein intake, and how well you’re sleeping. In fact, the effects are so minor that they may not even exist. As promising as calorie cycling sounds in theory, the research has been fairly underwhelming. There’s no great evidence that it yields significantly leaner gains.
That doesn’t necessarily matter, though, because whether you cycle your calories or not, you can get great results. If you follow a good hypertrophy training program, eat a good diet, and live a healthy lifestyle, you can build an impressive amount of muscle.
Does Intermittent Fasting Allow for Leaner Muscle Growth?
Intermittent fasting doesn’t allow for leaner muscle growth while bulking. If you’re trying to build muscle quickly, you’ll likely make leaner gains by keeping yourself in a more consistent calorie surplus. That way, you can build muscle steadily throughout the day. instead of intermittent fasting. However, it won’t impact your gains that much either way (study), and the difference may not even be noticeable.
The Benefits of Eating More Frequently While Bulking
There used to be rumours about “stoking the metabolic fire.” People thought they had to eat every three hours to maintain a healthy metabolism. That was disproven, and it was more of a fat-loss concern anyway. Most of us skinny guys aren’t worried about having underactive metabolisms.
When it came to bulking, bodybuilders worried that if they spent too much time fasting, their bodies would begin to eat away at their muscle mass (catabolism). That was also disproven. Intermittent fasting is okay for maintaining muscle mass, even in a calorie deficit.
However, research has turned up some genuine advantages to eating more often:
- If you eat twice as often, your bulking meals can be half the size. This allows guys with small stomachs to comfortably eat enough food while bulking, and it prevents the feelings of lethargy after large meals. One good way to take this principle even further is by having snacks between meals.
- More testosterone. Being in a calorie surplus allows you to build more muscle by improving testosterone production, cellular signalling and providing a constant influx of nutrients. The more time you spend in this muscle-building surplus, the more muscle you will build over the course of the day.
- Less cortisol? A recent study looking at 16:8 (LeanGains) intermittent fasting found that the group who skipped breakfast not only produced less testosterone, but also more cortisol—even while eating a comparable amount of calories overall. This would lead to less muscle growth and more fat gain. However, some of these hormonal changes, while not good for building muscle, might be good for improving your longterm health. So it would seem that intermittent fasting would perhaps be better for day-to-day muscle maintenance, but worse in terms of trying to build muscle leanly.
- More muscle-protein synthesis. Researchers have proven that every time you eat a meal that’s rich in protein, you trigger muscle growth (aka muscle-protein synthesis). This means that the more often you eat (up to a maximum of 5 meals per day), the more muscle growth you can stimulate.
Let’s dive deeper into that fourth point, about trigging muscle-protein synthesis. If we’re intermittent fasting, are we sabotaging our bulks by missing out on opportunities to trigger muscle growth?
Stimulating Muscle-Protein Synthesis
Dr. Layne Norton’s research is the most relevant here (study, study, study). We’ve already shown how lifting weights triggers a period of muscle growth that lasts for around 48 hours. But to take advantage of that opportunity, you also need to be on point with your diet. Norton found that when we eat a meal with enough protein in it, it triggers a surge of muscle growth that gradually slows down over the course of around six hours, like so:
This isn’t just “potential” muscle growth, this is your body actually constructing muscle. That means that if you eat three meals per day, you’d be having muscle growth spurts that look something like this:
Already we can see that skipping a meal is a missed opportunity for muscle growth:
This Nortonian model of muscle growth brings up some questions. First of all, if you miss a muscle gain opportunity, can you make up for it later by eating a meal that has extra protein in it? For example, what if we could do something like this:
Unfortunately, catching up is not possible. Norton’s research has proven that muscle growth is maximally stimulated with around 40 grams of protein. If you have more than 40 grams of protein in a meal, no additional muscle growth is triggered. So if you skip a meal, or eat a meal with too little protein in it, there’s no way to make up for it by eating more protein in the next meal. This means that it’s better to spread your protein intake out over the course of the day.
Protein Distribution Doesn’t Need to Be Perfect
It’s fine to eat more than forty grams of protein per meal. If you have more than 40 grams in a meal, that’s perfectly fine, and that might be needed in order to hit your daily macro goals, but it won’t trigger extra muscle-protein synthesis.
Twenty grams of protein still stimulates a lot of muscle growth. While eating 40 grams of protein per meal will get you the absolute ideal amount of muscle growth (100%), eating just 20 grams of protein will get you most of the results (80%). If you don’t hit 40 grams of protein in every meal, that’s fine, just make sure to get at least 20 grams.
For example, it’s common to have more protein with dinner than with breakfast, so a common way to distribute your protein over the course of the day might look something like this:
Your breakfast will still allow you to build muscle just fine, and the larger amount of protein with dinner will still be fully digested. It’s not perfectly ideal, but it’s pretty good. If you wanted to 100% maximize your muscle growth, though, you’d move 20 grams of protein from dinner to breakfast, giving you at least 40 grams in each meal.
How Often Can We Stimulate Muscle-Protein Synthesis?
This raises another question. How often can we stimulate muscle protein synthesis? Could we eat protein all day long, perpetually maintaining peak muscle growth conditions? What about something like this?
Layne Norton tested this idea and discovered that we can only trigger muscle growth once every four hours or so. If we eat meals more frequently than that, again, the protein will contribute towards our daily macros, but the meals won’t stimulate extra growth via muscle-protein synthesis.
This leaves us with an ideal meal schedule that looks something like this:
How controversial is this research? Could it be wrong? While there are still some questions about this theory, most of them are finer details, not issues with what we’ve discussed above. One of those finer details is that these spurts of muscle growth seem linked to one specific component of protein (leucine), not our overall protein intake. Dr Stuart McGill’s research has shown that some protein sources have more leucine than others, so it’s not quite as simple as just making sure to eat 40 grams of protein (study). For example, you can get maximal muscle growth with just 27 grams of whey protein, whereas you might need more like 50 grams of rice protein in order to get the same effect.
However, Norton’s overall research isn’t controversial. In fact, it’s the dominant theory among the top researchers in the field, including both Dr Eric Helms and Dr Brad Schoenfeld. To quote Schoenfeld:
The anabolic effects of a meal last a maximum of 6 hours or so. Thus, consumption of at least 3 meals spaced out every 5 to 6 hours would seem to be optimal for keeping protein synthesis continually elevated and thus maximizing muscle protein accretion. This hypothesis needs further investigation in a controlled long-term study.
Now, one discrepancy to note is that Norton recommends eating every four hours, whereas Schoenfeld recommends eating every 5–6 hours. While their recommendations are slightly different, their understanding of the research is not. Norton is simply erring on the side of eating more often, whereas Schoenfeld is erring on the side of eating a little bit less often. They’re both giving advice based on the same understanding of the science.
How Do Lifting and Protein Distribution Fit Together?
Both lifting and consuming protein increase muscle protein synthesis. We’re talking about the same phenomenon in both cases. After a good workout, muscle-protein synthesis will shoot up and then slowly decrease over the course of a few days. Eating a meal that’s rich in protein has a similar but milder effect that lasts for just a few hours.
If you consider that you’re going to have extra growth potential immediately after training, does that mean you should be eating extra protein post-workout? Yes. Some recent research is showing that after a hearty full-body workout, there’s a benefit to having some extra protein.
So you might consider your ideal workout day to look something like this:
This is a pretty classic bodybuilding diet, where you eat 4–5 meals per day and have an especially big post-workout meal. Fairly simple, and fairly ideal.
Should You Eat 4–5 Meals Per Day While Bulking?
Does this mean you should be eating 4–5 meals per day? Yes, but they don’t all need to be huge meals. You can trigger muscle growth just as easily with snacks, such as a bit of greek yogurt, a protein bar, a protein shake, or cottage cheese. These snacks may make your overall diet easier. They’ll allow you to have a smaller breakfast, lunch, and dinner. If you’re a skinny guy with a small stomach (like me), that can be a great advantage.
Don’t worry if you can only eat three meals per day. Just have breakfast early, have dinner late, and make sure your meals have at least twenty grams of protein in them. That meal schedule might not be perfectly optimal, but you’ll still get great bulking results, and you probably won’t notice the difference.
What About Growth Hormone?
One of the main purported benefits of intermittent fasting is increased growth hormone production. If we eat steadily throughout the day, we miss out on that extra growth hormone. Should eat more often to get more muscle-protein synthesis, or should we fast to get more growth hormone?
Let’s compare the two overall approaches.
Intermittent Fasting vs a Traditional Bulking Diet
We’ve looked at the muscle-building advantages of intermittent fasting, with the main advantage being greater growth hormone production. We’ve also looked at the muscle-building advantages of eating more frequently, with the main advantage being that you’d stimulate more muscle growth more often.
Which advantage is greater? Researchers have compared different meal schedules and concluded that having several meals spread out over the course of the day builds more muscle than intermittent fasting (study). In fact, a new study found that when overall protein and macronutrient consumption were identical, having breakfast increased muscle growth by 37%.
Eating 3–6 meals per day is ideal while bulking, especially if you’re skinny. However, once again, the difference is going to be very small. So small that it may not even be noticeable. In fact, some studies comparing intermittent fasting against a more normal meal schedule found identical amounts of muscle growth (study).
Eating more frequently may result in leaner gains. Since the amount of calories you eat determines the amount of weight you gain, and since intermittent fasting reduces muscle gain, this means that while the overall amount of weight you gain in either situation will be the same, you’d theoretically gain less muscle and more fat with intermittent fasting.
Eating more frequently makes it much easier to eat enough calories to bulk up. And keep in mind that if you have a smaller stomach or faster metabolism, eating more frequently is absolutely essential while bulking. Your stomach simply won’t be able to handle the massive meals of an intermittent fasting bulking protocol. (We’ve had members attempt this and wind up giving themselves acid reflux.)
The Best Types of Intermittent Fasting for Muscle Gain
By now, it should be clear that we don’t consider intermittent fasting to be ideal for bulking. However, nutrient timing isn’t that big of a factor when it comes to muscle growth. At most, skipping breakfast could reduce our muscle growth by around 37% (study). That might sound like a lot, but over the course of the twelve-week study, that’s a difference between gaining four pounds of lean mass versus gaining 5.5 pounds. It clearly shows that if our workouts, diet, protein intake, and sleep habits are on point, we can make good gains while eating anywhere from 2–7 meals per day.
This means that intermittent fasting is still a valid option, even while bulking. Furthermore, some intermittent fasting diets take some of our criticisms into consideration.
The BCAA Fast
The main disadvantage of fasting while bulking is the lack of muscle protein synthesis. However, what if it were possible to stimulate muscle protein synthesis while fasting? This would allow you to get the best of both worlds, right?
Supplementing with leucine or branched-chain amino acids (BCAAs) sort of allows you to do that. They contain enough of the amino acid leucine to trigger muscle-protein synthesis, but they contain so few calories that Martin Berkhan still considers it fasting. The downside is that since you’d still be in a calorie deficit, there wouldn’t really be any muscle growth going on. (The strategy works better while cutting, as the BCAAs prevent muscle loss and improve workout performance.)
24-Hour Fasts
There are also types of intermittent fasting where you only fast for one 24-hour period each week. The most famous version of that is Brad Pilon’s Eat, Stop, Eat approach, and that’s also the approach Dr. John Berardi used when testing out an extreme bulking plan on the fitness blogger Nate Green (Bigger, Smaller, Bigger).
There are three benefits to doing 24-hour fasts:
- They give your digestive system a break from overeating. This might not give you any physiological benefit, but if you’re sick of being full, it can be psychologically pleasant.
- You get to burn a little bit of fat right in the middle of your bulk. Mind you, you may also lose some muscle.
- You’ll still be growing at full speed 86% of the time. That’s a big improvement compared to 16:8 fasting, where you’d only be growing at full speed for 67% of the time.
There are also three downsides to 24-hour fasts, though:
- You won’t be gaining muscle on the day you’re fasting, reducing your overall rate of muscle growth.
- Spending 24 hours without eating can be extremely unpleasant for some people.
- Going to bed without eating enough food that day can make it hard to get a good night’s rest. You may even bolt awake in the middle of the night, pumped full of cortisol, ready to hunt.
The Skinny Guy’s Muscle-Building “Fast”
There are two significant advantages to intermittent fasting while gaining muscle:
- Skipping breakfast is pleasant and productive. Most skinny guys wake up without much of an appetite, making breakfast more of a chore than a treat. Moreover, eating a big breakfast can use up our morning energy on digestion, especially if we have weaker digestive systems (and many of us do).
- Our digestive system gets a break from overfeeding. Bulking diets can be brutal on skinny guys. There are just so many damn calories that it can feel like a relentless assault on our stomachs and energy levels. Taking a day off each week where we don’t eat any calories can be a welcome break.
However, there are also two major downsides to intermittent fasting:
- Less muscle growth, more fat. When you’re fasting, your muscles aren’t growing. This will not only slow down your muscle gains, you’ll also gain more fat.
- Intermittent fasting makes eating enough to gain weight way harder. It’s hard enough to eat a bulking diet when you’re eating 3–5 times per day. Cram those calories into a couple of meals over the course of a few hours, and it becomes downright brutal. Who wants to eat a 1,500-calorie lunch? Lots of people, sure, but I’d rather stick a fork in my eye.
So, how can we min-max our muscle-building results based on all of this research? I have two intermittent fasting protocols you might want to experiment with. Keep in mind that you’re always free to follow a traditional bulking diet, eating 3–5 regular meals per day. But if you find yourself wanting to experiment with intermittent fasting for muscle gain, here’s what I recommend instead:
The Mini-Meal Reverse Cheat Day
24-hour fasts allow your digestive system to take a break, and it might give you a chance to lose a little bit of fat right in the middle of your bulk. That’s great, but we can accomplish all of that without any fasting whatsoever.
Instead of fasting once per week, we recommend having a “cheat day.” But instead of doing the fat-person cheat day, where you eat extra food, we recommend doing the skinny guy’s cheat day, where you eat less food. You can still eat several times per day, just keep your protein intake high and your calorie intake low. Your digestive system will love the break, and you’ll lose some fat. (This is how Jared gained 33 pounds in three months, as shown above.)
You’d have a meal schedule something like this:
Monday: full-body workout, eat big
Tuesday: rest, eat big
Wednesday: full-body workout, eat big
Thursday: rest, eat big
Friday: fully-body workout, eat big
Saturday: rest, eat big
Sunday: take a break from eating big
The Light Breakfast
Skipping breakfast increases morning productivity, but you miss out on an opportunity to stimulate muscle growth. One solution is to have a protein-rich breakfast that’s smaller and lower in calories.
This light breakfast could be a protein shake and some fruit, a protein bar and a latte, or even just a smoothie. All of those will be quite easy to digest, they aren’t very filling, and they can contain at least 20 grams of protein. The meal will be light enough that you’ll still be productive, you won’t fall too far behind on calories, and you’ll kick-start some morning muscle growth.
These half-fasts are what Dr. Layne Norton recommends to bulkers who are curious about intermittent fasting:
If you want some of the benefits from intermittent fasting but want to optimize muscle mass, I would advise a different type of fast. Rather than cutting out all calories, simply restrict carbs and fats during your fasting window, but continue to evenly distribute your protein intake throughout the day.
Take this approach, and you are still going to get a large volume of food in the feeding period and spend a large portion of the day in a low-insulin fat-burning state, but you’ll be able to distribute protein in such a way that is better for muscle growth.
Layne Norton, PhD
This is what we recommend to our members, and this is how I managed to gain 55 pounds over the course of a couple of years:
New Intermittent Fasting Research
2020 Study on Intermittent Fasting for Muscle Gain
A new study by Tinsley et al. looked into the results of using intermittent fasting for muscle gain. They compared muscle growth between different groups of women, some of whom were eating steadily throughout the day, others who were intermittent fasting (using a 16:8 protocol). What’s interesting is that these women were bulking on a modest calorie surplus of around 200 extra calories per day, and there were no differences in muscle growth between the groups. This seems to show that, at least with slower rates of weight gain, intermittent fasting doesn’t reduce our ability to build muscle while bulking.
I reached out to Eric Trexler, PhD, for his thoughts on what to make of this for guys doing a bonafide bulk (eating in a larger calorie surplus and gaining closer to a pound per week). He told me the following:
It’s certainly possible that results could’ve been different if they pushed for a particularly rapid rate of muscle gain, but we can’t be sure. There are certainly some downsides of IF, and I don’t see a ton of utility when it comes to bulking. The primary benefit seems to be satiety management when caloric intake is low. I can’t imagine intentionally nudging somebody toward time-restricted feeding unless they were struggling with hunger, or simply couldn’t accommodate more meals into their eating schedule due to timing/logistics.
As noted in the [Monthly Applications in Strength Sports] article, it is interesting that interventions don’t seem to show a detrimental effect on hypertrophy. Based on the research to date, I’m left to assume that the robust effect of resistance training on 24-hr protein synthesis is essentially “washing out” the small benefit of more carefully scheduled protein feedings for initiating frequent spikes in muscle protein synthesis. However, I think the “default approach” for bulking would still be shooting for 3-5 meals spaced throughout the day.
And as more research comes out on the topic, I feel less and less confident telling someone that they’re making a huge mistake by adopting a time-restricted feeding window, from a muscle retention/hypertrophy perspective.
As far as my own take on this, I think I might need to adjust my graphs to show a larger boost in muscle-protein synthesis from lifting weights and a smaller boost in muscle growth from individual meals. I think that’s going to give us a clearer visual representation of how intermittent fasting affects muscle growth while bulking.
I’ll keep my eye on the research to see what else happens. Intermittent fasting remains popular, so I think we’re going to have plenty of new studies coming out, hopefully with some of them conducted on men who are bulking up more quickly.
2020 Study on Protein Distribution for Muscle Growth
We have a brand new study comparing the effects of protein distribution on muscle growth. What’s nice about this study is they measured how much lean mass was gained, giving us an idea of what the differences are likely to add up to in the real world.
In this study, the participants were put on a twelve-week weight training program. Half the participants were given a breakfast that was extremely low in protein, whereas the other half were given a normal breakfast containing an average amount of protein. Both groups ate the same amount of protein overall, and both diets had the same macronutrients. The only difference was the schedule.
What we see is that eating protein in the morning increased muscle growth by around 37%. It also yielded larger increases in strength.
This lines up with previous research and expert recommendations fairly well, giving us more confidence that intermittent fasting isn’t ideal for building muscle. It can work, but this study suggests that we’d be able to gain muscle 37% faster simply by eating a protein-rich breakfast.
2020 Study on Intermittent Fasting for Cutting
A new intermittent fasting study just came out, and what makes this one special is that it’s one of the largest and longest ones ever conducted, improving the strength of its findings.
Both the intermittent fasting and the control group were given instructions about how to eat a good diet. Both groups lost a similar amount of weight—around 2 pounds. And both groups lost a similar amount of fat. The differences weren’t dramatic. But the intermittent fasting group started to subconsciously move a little bit less, slightly reducing their metabolism.
The main finding, though, was that the intermittent fasting group lost more muscle mass. Protein wasn’t tracked, so maybe the intermittent fasting group lost more muscle because they were eating less protein. Maybe it was because they were moving less, stimulating their muscles a little bit less. It’s hard to say for sure, and so it’s hard to say how these findings might apply to you.
What’s interesting is that the lead researcher, Ethan Weiss, was a fan of intermittent fasting. Up until running this study, he was doing intermittent fasting himself. But after seeing these results, he decided to go back to eating more meals.
2021 Meta-Analysis on Intermittent Fasting for Cutting
A meta-analysis by Ashtary-Larky and colleagues found that intermittent fasting might help people lose more fat while cutting (study). The intermittent fasting group also lost slightly more muscle, but it wasn’t a meaningful difference.
2022 Study on Intermittent Fasting & Muscle Growth
Parr and colleagues assigned eighteen men to either an intermittent fasting group or a control group (study). The intermittent fasting group ate their meals at 10AM, 2PM, and 6PM, giving them an eight-hour feeding window. The control group ate the same quantity and quality of food, but they ate their meals at 8AM, 2PM, and 8PM, giving them a twelve-hour feeding window.
Both groups lost a little bit of weight. The intermittent fasting group lost more muscle and less fat. The control group lost more fat and less muscle. This study hints that a regular eating schedule might be better for our body composition, but since both groups were in a calorie deficit, it doesn’t directly tell us anything new about intermittent fasting while bulking.
A 2023 Meta-Analysis on Intermittent Fasting & Appetite
Up until now, I’ve thought intermittent fasting reduced appetite or at least made it harder to eat as many calories. However, a new meta-analysis by Elseworth and colleagues found it had no effect on appetite or weight loss. Since this meta-analysis includes all the studies that came before it, it’s the strongest evidence we have.
This might suggest that intermittent fasting could be viable while bulking, but I’m still skeptical. One of the biggest challenges with bulking is having to struggle through overly large meals, feeling hot and lethargic afterwards, and potentially dealing with issues like acid reflux. When huge meals come later in the day, they can also interfere with sleep. That leads me to believe that intermittent fasting would make it harder to bulk, especially if you’re already pushing against the limits of a too-small stomach.
2024 Study on Protein Distribution
Jorn Trommelen led a new study on protein timing, finding that 100 grams of protein per meal stimulated more muscle-protein synthesis than 25 grams per meal. This sounds like it challenges older research. It seems to make a case for the viability of intermittent fasting (and it might).
However, we already knew that 25 grams of protein isn’t enough to maximize muscle-protein synthesis. You’d expect more protein synthesis with 40 grams. So it makes sense that 100 grams would stimulate more muscle-protein synthesis than 25 grams.
Still, this new study suggests you might be able to maximize muscle growth with fewer meals, provided you still eat enough protein overall. That’s a point in favour of intermittent fasting.
2024 Meta-Analysis on Intermittent Fasting for Weight Loss
A big new meta-analysis by Wan and colleagues found that intermittent fasting tends to cause weight loss. No big surprise there, but this is the largest study to date, giving us the most confidence.
Summary
Overall, intermittent fasting seems to slightly impair muscle growth while making it harder to get into a calorie surplus, making it harder to bulk up.
Most of the rumours about intermittent fasting are false. Fasting doesn’t cause instant muscle loss, skipping breakfast doesn’t harm our metabolisms, and we can digest eighty or more grams of protein per meal without issue. Most of all, many people find that fasting makes it easier to get into a calorie deficit, allowing them to lose weight more easily. It’s popular for a reason.
But intermittent fasting probably isn’t ideal for gaining muscle. Not only does it seem to slightly slow muscle growth, but it also makes it harder to gain weight and harder to keep those gains lean. Plus, the supposed benefits, such as increased growth hormone production, don’t seem to have any impact on muscle growth (study). So, although intermittent fasting doesn’t make it impossible to gain muscle, it might make it harder and slower.
If you want to gain muscle as fast and as leanly as possible, it’s better to eat 3–7 meals spread relatively evenly through the day, as bodybuilders have been doing for the past hundred years. It’s not the only way to build muscle, but it makes for a good default, especially if you’re a skinny guy who has a hard time gaining weight.
Alright, that’s it for now. If you want more muscle-building information, we have a free muscle-building newsletter. If you want a full workout and diet program, including a 5-month customizable full-body workout routine, a diet guide, a recipe book, and online coaching, check out our Bony to Beastly Program. Or, if you want a customizable intermediate muscle-building program, check out our Outlift Program.
Shane Duquette is the founder of Outlift, Bony to Beastly, and Bony to Bombshell, each with millions of readers. He's a Certified Conditioning Coach (CCC), has gained 70 pounds, and has over a decade of experience helping more than 15,000 people build muscle. He also has a degree in fine arts, but those are inversely correlated with muscle growth.
Marco Walker-Ng is the founder and strength coach of Outlift, Bony to Beastly, and Bony to Bombshell. He's a certified trainer (PTS) and nutrition coach (PN) with a Bachelor's degree in Health Sciences (BHSc) from the University of Ottawa. He has over 15 years of experience helping people gain muscle and strength, with clients including college, professional, and Olympic athletes.
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Bulking takes consistent work and financing. Almost every guy falls because it’s too hard to get all of that support and stay motivated long-term. The body reverts back to its original shape and form within 2-months of stopping the bulking focused work. Don’t waste time.
Hey man, bulking is indeed hard work. Many guys do fail, and that’s why those who succeed are rewarded so highly for it: they prove to themselves and everyone else who sees them that they can accomplish difficult tasks. When you see a guy in great physical shape, you know that he can work hard, that he can handle his finances, that he can stick with his goals long-term, and that he has the support he needs to succeed in life.
The body doesn’t revert back to its original shape and form, though. The more important adaptations that your body makes from building muscle are permanent. For example, your muscle fibres bring in myonuclei from satellite cells, making your muscles more insulin sensitive and your body able to support greater muscle mass. This is colloquially called “muscle memory,” and it will last your entire life, making you forever leaner and more muscular. We’ve written more about that here:
https://bonytobeastly.com/skinny-changing-set-point/
(We still recommend keeping up with a healthy diet and exercise routine, though, of course, but that’s important whether you build muscle or not.)
Inspiring that you found YOUR confidence and some passion through doing this, Shane. Many do not. Many cerebral guys have no interest in dead-lifting 300 or 400lbs and becoming more of a meat-head. However, bodies do revert or become ‘fattier’ in lieu of the muscle that once was perhaps more pronounced when the program or routine ceases…consider it an appropriate reaction and homeostasis to the *inflammation* that the work causes when the routines can’t be upheld. In addition, age is a factor! Testosterone declines every year after 30. I don’t know which world you live in, but most physically-fit men I know become too into themselves, cheat on partners, shark their way in corporate and cut pushed back down, or even end up in the sex industry as masseurs and escorts, etc. That is not ‘financial support’. That is desperate hustling to keep the vicious cycle going that only proceeds in a negative feedback loop. Why? Because we’re human, not machines, and our lives are finite that slow in pace over time.
*fall* verses *fail* in original post. People fall from grace. Becoming a surly, obsessed, angry health-nut or exercise fiend is a fall from grace and intellectual cultivation. Mild exercise is ok, especially for ‘Depression’ which academics suffer from frequently. High intensity like HIIT or Cross-Fit often yield injuries.
All of the research I’ve seen has shown a positive correlation between lifting weights, confidence, intelligence, and emotional well-being. Many benefits come from doing cardio as well, but both lifting and cardio give separate benefits, so doing both is even better than doing one or the other.
I can’t imagine why being stronger, healthier, and successfully accomplishing a difficult task would make someone less confident or less happy, but I’m sure it happens to some people. I’ve never encountered one of those people. I suspect they’re rather rare.
Building muscle has a positive effect on brainpower, so being a meathead is a bit of a misnomer. Yes, there are dumb people who lift weights, but they’re smarter than they would have been if they didn’t lift weights. It’s helping, not hurting. (Again, similar but different effects from cardio. Best to do both.)
You don’t have to deadlift 300–400 pounds in order to build muscle or be healthy. You’re strawmanning me here. I’m personally glad that I was able to accomplish my goal of lifting 405 pounds, but I have no doubt that when I was lifting 315 I was just as healthy. (My bone density reached the optimal level before I deadlifted 405 pounds.)
Muscle does not in any way transform into fat. If anything, having formerly been muscular makes one more resistant to gaining fat, and more likely to gain muscle when overeating. The formerly strong guy who becomes fat will have a better physique than the formerly sedentary guy who becomes fat.
As for cheating… don’t cheat? Not sure what that has to do with going to the gym. Yes, guys with naturally high testosterone may be more likely to cheat, but again, that has nothing to do with going to the gym or building muscle.
Anyway, none of this has anything to do with intermittent fasting while bulking.
What in the holy hell are you going on about? Sex industry? Cheating? Are you having a stroke or just trolling?
LMAO!!!
Obvious troll is obvious
If you’re done trying to use as many big words as you can to try to seem smart the rest of the readers here would like to actually have meaningful conversations. I don’t know what world you live in….. but the amount of stereotypes you just threw out basically highlights that you have very little life experience, and choose to generalize your narrow view of successful bodybuilders being sex crazed vein losers with no focus, to the rest of the world. Well we all live in different places and I don’t know a single person like that. Do I dare say a person like that doesn’t exist? No I don’t because I won’t generalize a group of people (fitness and bodybuilding) to a faceless stereotype. You sound sad, discouraged, defeated and like you have no motivation left. If your experiences haven’t been good o hope they will be in the future. In the mean time keep your toxic crappy opinions to yourself.
This is true. I have followed a very similar workout and diet approach as what is recommended by bony to beastly(based off Dr. Schoenfelds work). I went from 148 to 185 lbs over a 3 month period. I was able to gain another 10 or so lbs after that. Due to work and diet changes I lost weight, but the smallest I have ever dropped to is ~170. That is with low protein and no exercise. So my set point has changed.
Very interesting article! But I have one question:
– What is the importance of hitting your daily protein goal?
Let’s say you are a 160lb guy and you skip some meals but you get all you protein in later that day in huge portions (e.g. 2 meals with 80g of protein) and hit your daily protein goal.
What’s the benefit of that over eating 2 meals with 40g of protein that evening and only hitting half of your daily protein goal?
Because you can’t catch up and won’t stimulate more muscle protein synthesis with those 80g protein meals if I understand correctly?
Thanks in advance!
That’s a good question, your logic seems sound to me, and I’ve wondered the same thing myself. Let me walk you through what I know and what I think, but this is something I’ve been looking into as well. So, while I feel confident in the “what” and “how,” I feel like I’m missing part of the “why.”
1. Studies find that those who eat less than 0.8 grams of protein per pound bodyweight per day don’t build as much muscle as those who eat more, regardless of when they eat it. So we know that this is important. In fact, it’s more important than when you eat the protein.
2. Studies also find that the best way to distribute that protein is relatively spread out, with at least 20 grams in each meal, rather than having it all at once. This is newer research and seems to have less of an impact, which is why people can gain muscle even while following extreme intermittent fasting protocols, such as the warrior diet, where you have just one giant meal each day.
3. Furthermore, the research shows that no matter how much protein we eat in a meal, our body is still able to digest and use all of it. This means that if you have 180 grams of protein with dinner, and that’s the only thing you eat all day, your body is still going to get the benefit of eating 180 grams of protein.
However, if you’re hitting your daily protein goal but you aren’t spreading out that intake throughout the day, you wouldn’t get the EXTRA benefit of stimulating these boosts in muscle-protein synthesis.
Perhaps we can look at our calorie intake the same way. Let’s say you need to eat 3,200 calories per day in order to gain a pound per week. Option A is to eat four 800-calorie meals, keeping you in a hearty surplus all day, with your testosterone high and your cortisol low. Option B is to eat one 3,200-calorie meal, meaning that most of the day you’re in a calorie deficit, your testosterone is low, your cortisol is high, and you don’t have an influx of nutrients. In both cases, you’ll absorb all of those calories, and therefore in both cases you’ll gain weight. Your total calorie intake is priority #1. However, if you spread those calories out throughout the day, your gains will be leaner, as your body can constantly build muscle all day long.
I suspect something similar is happening with protein.
Does that help at all?
Just wanting to check out one point you make Shane- thank you so much for these articles! – deeply appreciate the ongoing work you guys are doing!
You say that gains are leaner by spreading out protein and not fasting…but that goes so against many things I have read suggesting that gains are substantially leaner whilst implementing a fasting Regiment….less of them of course…but certainly leaner…due to various factors from increased insulin sensitivity to growth hormone etc….what do you say to that?…are you really of the opinion that you will stay leaner whilst not fasting?…and if so what’s the point of every fasting at all?…
Thank you – harry
My pleasure, Harry! Glad you liked it.
Yes, your gains will be leaner if you eat 4–5 meals spread out throughout the day. Intermittent fasting would actually be a little bit worse for gains than even the traditional 3-meals-per-day schedule of breakfast, lunch and dinner with no snacks.
If you gain weight more slowly while following a bulking program (good lifting, diet, and sleep), then that weight gain has a better chance of being lean. That’s simply due to the calorie surplus being smaller, though. You could do that by intermittent fasting, but your gains would be even leaner if you ate more meals and spread them out over the course of the day.
There are some interesting long-term health benefits to fasting, but the main reason it’s so popular is because it helps people eat fewer calories with less suffering, allowing them to drop into a calorie deficit and burn fat. For most people, that’s a HUGE benefit. After all, keep in mind that trying to eat MORE calories in order to gain weight is a niche issue. Most people are trying to eat LESS calories in order to lose weight.
If you mean “what’s the point of fasting while bulking?” then, ah, there isn’t really much of a point. It’s not very good for bulking. Although I suppose if your appetite were so enormous that you had trouble keeping your calorie surplus under control, then maybe you’d prefer intermittent fasting?
I hope that helps!
Thanks for all the info! Great article.
My pleasure, Evan!
Very thorough article as always. Makes sense mostly. However there are a couple of key points to highlight.
1. IF really works only with a high (good) fat diet with moderate protein and low carbs. This helps comfortable fasting for 16+ hours where the body switches from glucose to fat for energy and all the fat loss happens. So the following paragraph declaring that IF causes fat gain by assuming one eats the same amount and type of calories is a gross mischaracterization:
“Since the amount of calories you eat determines the amount of weight you gain, and since intermittent fasting reduces muscle gain, this means that while the overall amount of weight you gain in either situation will be the same, you’ll gain less muscle and more fat with intermittent fasting.”
As a side note, such a (keto-like) diet is good for anyone even if not fasting and helps hit the right macro ratios.
2. There are other benefits of fasting you’ve missed like immunity system boost, improved liver functioning, better sleep etc all of which help in long term muscle gain and fat loss.
3. The bit on fasting increasing cortisol is a red herring. I found this on a good IF website that addresses this thoroughly:
“Exercise also raises cortisol, so should we not exercise? Dieting will lead to more cortisol, as will low carbohydrate diets, coffee, etc. – do we warn people about that? We like cortisol during exercise as its release leads to mobilization of fatty acids from fat stores thus providing us with energy. After a workout where glycogen is depleted, cortisol is raised to spare glucose and then when you eat post-workout, it will offset this. Cortisol is NOT bad – it’s just a hormone. It is released in a pulsatile fashion and its release in the morning is part of what helps us get moving. CHRONIC high levels of cortisol can certainly be a problem and negatively impact the immune system, but acute responses are normal. Please stop vilifying hormones like cortisol and insulin simply because you read a headline and don’t understand all of their functions in the body. Transient increases during a short time of fasting or exercise or fasted exercise or a stressful situation, are not too much for our body to handle. If such a minor stressor (fasted exercise) was so detrimental, we would not have evolved to where we are today. As a matter of fact, one of the main benefits of intermittent fasting is its ability to boost the resiliency of cells in response to “stress.” Cortisol and fasting are often pitted against each other in certain fitness circles. Those who preach, “Beware of cortisol increases in fasting,” are typically using cherry picked studies that don’t accurately depict the discussion at hand or simply ignore the entire picture. For example, some of the common studies for those in this camp include one where the participants fasted for 5 straight days and cortisol increased. Well of course, why wouldn’t it? Your body is trying to spare glucose. This leads to clickbait-esque thinking…fasting = more cortisol and cortisol = bad therefore fasting = bad.”
4. I agree with calorie cycling and ensuring that there is a higher intake after workout. But the following paragraph is very questionable:
“However, don’t worry if you can only eat three meals per day. Just have breakfast early, have dinner late, and make sure that all of your meals have at least 20 grams of protein in them.”
If you are eating 3 meals a day, you are much better off doing the opposite! Eat a late breakfast, early dinner and make sure that you eat the 3 meals four hours apart (say 11am, 3pm, 7pm) and fast the remaining to get the best of both worlds.
Hey RR, thank you for the long and thoughtful answer! You’ve raised some good points. Let me go through them.
1. When doing these articles I think it’s more helpful to take the best possible argument on either side. You’ll notice that on the intermittent fasting side, I’m referencing guys like Martin Berkhan, Brad Pilon and Dr John Berardi, all of whom I have a tremendous amount of respect for. I’m familiar with their plans and when comparing intermittent fasting against eating more frequently, I’m assuming that in both cases the macros and nutrition quality are fully optimized. I’m comparing the very best intermittent fasting diet against the very best traditional bulking diet. Even then, intermittent fasting is not ideal for bulking. I don’t even think the best intermittent fasting advocates would disagree with that, as they tend to recommend intermittent fasting for cutting and general lifestyle, not bulking.
2. I did mention that intermittent fasting has some interesting possible longterm health benefits. However, bulking is a short-term endeavour. I’ve spent around 18 months of my life bulking, gaining roughly 55 pounds of muscle during those months, and even those 18 months were split up with breaks. Now, goals accomplished, I do rather enjoy intermittent fasting… but still I wouldn’t recommend it to someone who was interested in building muscle quickly. If someone asks me how to bulk, I’m going to teach them how to bulk. When they’ve gained the 20+ pounds they’re after, then we can transition into a healthy long-term routine. Those two routines are somewhat different. Bulking means eating too much, lifting too hard, and prioritizing protein. Longterm health is about going back to eating the right amount, lifting a bit less intensely, adding in some cardio, more focus on fruits/vegetables, etc.
3. It’s good to point out the misconceptions surrounding cortisol. It’s not a “bad” hormone, it’s a stress hormone, and just like with stress, the goal isn’t to get rid of it completely, it’s just to strike that proper balance. Yes, we want to stress ourselves both in the gym and elsewhere in life. No, we don’t want to be chronically stressed all the time. Where is the proper balance point for our specific goal? In this case, spending an extra 8-ish hours each day with elevated cortisol probably isn’t ideal, at least not for muscle growth.
4. Intermittent fasting isn’t ideal for building muscle, so we don’t want to introduce intermittent periods of fasting into our bulking routine. You’re correct that after a few hours we can boost muscle growth by having a protein-rich meal, but that doesn’t mean that the previous boost has fully ground to a halt within four hours (as shown in the diagrams). It’s likely still better to spread those meals apart.
Thanks again for the thoughtful comment, and let me know if you find any of those answers unsatisfactory or if you have any other objections 🙂
Thanks for the quick and detailed response, Shane.
On #1, I agree with you on the bulking part. IF likely causes muscle gain to be slower. I just disagreed on the part where you said IF causes more fat gain than eating frequently. It goes against the premise which you’ve also stated that IF is best for cutting.
On #2, I totally agree. IF is not ideal for a short term endeavor of quick bulking. It’s more a long term health routine with slow and steady muscle gain as long as we eat caloric surplus. I’ve gained 10 pounds in 6 months of IF and I am okay with that pace given the health benefits. It depends on one’s priorities.
On #3, I don’t think cortisol stays elevated for 8+ hours with IF. It’s more a case of acute short term increases while the hunger pangs come (which are less frequent as one does more IF). IF is proven to cause better sleep and that wouldn’t be the case if there was chronic cortisol spike.
On #4, yeah I see your point. Goes back to #2 above as to what one’s priorities are.
My pleasure, RR!
On #1, I think we’ve found the disagreement and mended it. I’m just talking about bulking in this article. Since there’s a calorie surplus when bulking, and the degree of the calorie surplus dictates the rate of weight gain, then if muscle gain is slower, more of that weight gain will come from fat. For example, if you’re gaining 1 pound per week due to your calorie surplus, better to be gaining muscle more quickly so that more of that pound is muscle. When someone is cutting, there’s no calorie surplus, and thus no risk of fat gain anyway. In this case, where there’s a calorie deficit, intermittent fasting is fantastic (and my personal preference).
On #2—excellent. I hope I made it clear in this article that much of this comes down to personal preference. There are some fundamental aspects of muscle gain where there’s really no room for compromise: you need a good resistance training program, enough calories, enough protein, and enough quality sleep… but meal schedule is not a big deal. You can bulk just fine while intermittent fasting. This article was more for people looking to min-max their bulking plan, trying to get the most bang for their buck. But I wanted to make it clear that if someone is okay with slower results and prefers intermittent fasting, that’s no problem whatsoever. I don’t even think it will substantially slow progress.
On #3, the study I referenced found that overall levels of cortisol were higher in the intermittent fasting group. That could be from a series of spikes. Either way, I’m not sure that’s a great thing while bulking. Probably better to limit added stress while your body is already making such a monumental effort to pack on muscle. Again, though, not the end of the world.
Like I said earlier, I think we’ve largely solved the disagreement. In this article I’m writing about the best way to bulk—and not just to bulk, but to really build muscle as quickly and leanly as possible. For different goals, or for people with different timelines or priorities, things change 🙂
This skinny guy wakes up every morning simply ravenous, so I would never be able to fast until noon. “Most skinny guys wake up without much of an appetite, making breakfast more of a chore than a treat.” Now if only I could match my stomach capacity with my appetite, I could eat a lot more than I do.
This site is a favorite, and incredibly thorough! As a life-long ectomorph (slowly moving towards meso :P), and a certified personal trainer, I can see this info is spot on and very well analyzed! I’ve even picked up a few tips on meal strategy from you guys. I got your eBook; keep up the fantastic work, dude!
With that said, I can’t tell you how many people – ecto or not – try to BS diet and just gloss over what calories do. It’s just as hard for us to hold weight as it is for the rest of the world to lose it! My clients laugh when I’m eating so much all the time…but they’re the first to ask “WOW! Are you on steroids now?!” 😛
Keep up the good fight, gents!
Glad you’re loving the site, Jason! Thank you so much for the kind words.
Always know you’re doing everything right when the steroid accusations roll in 🙂
This is EXACTLY what I needed. Thank you SO much for putting this together…
I’ve been testing out intermittent fasting for my first month of bulking and my muscle gains are tiny and slow going! This all makes perfect sense…
The last time I tried bulking I had several meals throughout the day and gained weight like crazy (until I went back to running long distance and lost it lol)
What put me off previously was I put on belly fat and it just put me off the whole bulking thing because I didn’t FEEL great despite the muscle gain, after 3 months I hated all the extra fat!
Now I feel like I could just intermittent fast for maybe a week or so whenever I want to cut down the fat and keep my muscle on! And continue to workout…
One question I still have thats unanswered on a separate topic..
Is it better to work out 3 or 4 times per week for ectomorph bulking Shane??
Putting lifestyle and any other timing stuff aside. Which is actually better?
Thanks,
Sam
with maturity I’ve come to a point where I ask myself differents questions. I am really wondering how healthy it is to litteraly force yourself into a bodyweight that every part of your body deseperetly trying to fight back.
I have become intereseted in longevity diet and how those 100y old people who lives in the “blue zones” almost all advocates some form of caloric restriction. I know that caloric restriction hasnt been fully proved scientifically for longevity, and also that this website doesnt focus on longevity, but I just wanted to say that maybe if cerebral people happen to be so skinny, its maybe because they are meant to use their body and their brain in another way instead of just trying to look like the “standard” wich is a biologic non sens.
Just my 2 cents!
I’ve been a skinny-fat guy for a while – very much an ectomorph (6’1″ and 169lb with 19% body fat) but I’ve always had a healthy appetite.
I did 16:8 IF for three months and was down to 155lb, but still with 17% body fat – dropped a trouser size, but also a fair chunk of muscle.
I’ve since started weight training and increased my protein intake to prevent the muscle loss. Mirror test tells me I’m around 15% body fat now, but my weight had gone back up to 158lb. I plan to continue lean bulking until and go back to IF when I need to cut.
Hi, great article!
During a long time I’ve been trying to decide if I should several times a day or do the intermittent fasting but after this article I decided to do the first one.
The only problem is that I kept reading other articles you wrote and in this one (https://bonytobeastly.com/how-many-meals-per-day/) it says you are actually just eating 2 times a day so I guess IF.
Why is that? Is is then the same if I eat 2 or 3 times a day in a 8 hours window (16:8)??
Hey Jonathan, it just depends on your goals.
I’ll often skip breakfast (16:8), and that’s great for maintenance, it’s great for losing fat, and it’s even okay for building muscle slowly. However, if I’m really trying to emphasize muscle growth, it’s better to eat several times per day, it’s better to spread those meals out throughout the entire day, and it’s best to have protein in each meal.
That could be something like:
-Breakfast at 8am
-Lunch at noon
-Snack at 4pm
-Dinner at 8pm
-Snack before bed at 11pm
(The snacks aren’t essential, but they would help.)
As explained in this article, intermittent fasting is great for many goals, it just so happens that it’s not ideal for bulking.
Hi Shane,
Incredible source of knowledge. Thank you very much.
Here is what i wonder: Is there a caloric limit as well to trigger muscle growth? or Is eating more than 20gr of protein enough to start muscle growth period? So what if we just have one scoop of whey protein with some water?
All the best
Hey Myers, good question. You need to be in an overall calorie surplus in order to reliably gain muscle, not to mention it will radically improve your hormone production. However you can certainly have some lower-calorie meals that are high in protein, and those will still stimulate muscle protein synthesis. Just make sure to be in a surplus overall, i.e., gaining weight at the intervals you’re aiming for.
In the b2B program, we recommend hitting daily calorie goals and measuring your weight weekly to ensure that you’re gaining weight. However, some members cycle their calories, aiming for more calories in the meals following their workouts and fewer calories in the meals that are more distant from their workouts. You’d take that same daily calorie target (say 3,000 calories) but spread it out unevenly over the course of the week, for example having 2,500 calories on rest days (4 days per week) and 3,667 calories on workout days (3 days per week), still giving an average of 3,000 calories per day over the course of the week. That produces phenomenal gains in muscle so long as they hit their daily goals and gain weight at the end of the week 🙂
(Intermittent fasting is also a form of calorie cycling, it’s just that the timing of it wouldn’t align as well with the workouts, and the protein distribution doesn’t align with optimal muscle-protein synthesis.)
Hi Shane,
Tysm for thorough information!
I just wonder one thing: Say, during 8-hour feeding period, I eat a caloric surplus of 40/40/20 carb/protein/fat in order to gain muscle mass (since carb is more necessary when bulking than cutting) and spreading it over 3 meals (each with 3 hours apart), is it possible to gain more muscle mass? Or most of them will turn to fat instead, to which IF will balance out the result? I am now doing IF, trying to lose fat to below than 15% before bulking up again. And since I like the benefits of IF so much, I just wonder how to fit IF in a daily life when bulking. The idea of eating snacks throughout the day doesn’t fit me for eating is not allowed in class lol.
Thank you for your reply! And if I misunderstood anything (maybe a lot lol), don’t hesitate to correct me!
Hey Otter, no, as far as I can tell, you haven’t misunderstood anything 🙂
It’s okay to eat three meals within that eight hour period. It’s not ideal, but it’s okay. If you’re willing to sacrifice some results in order to have a better lifestyle, that’s totally understandable. What matters the most is sustaining your efforts over a long period of time. Getting results quickly can be motivating, which can encourage you to keep pushing, but you should still be able to bulk fairly well even while intermittent fasting provided that all of the other bulking details are on point (a good workout program, enough calories, enough protein, and so on).
However, you may want to experiment with the “skinny guy’s bulking fast” that we recommend near the end of the article. That would involve just a small meal in the morning, and that would speed up your muscle gains with little additional effort. It will probably FEEL like you’re intermittent fasting, too, since you won’t be full and it won’t take more than a minute to eat breakfast.
I hope that helps, and good luck!
I’m curious if in your research you found anything about protein before bed/in the middle of the night? Or I guess the bigger question is are the behaviors you focus on in this article changed at all during sleep? Great article, thanks!
Dear Shane
37 y.o. male,ectomorph through and through.
193cm high and 76kg’ heavy (167,5lbs) a all time low as an adult.
After a lifetime of training, “adultlife” came knocking.
With work, stress, illness, death and all kind of bad things that can break a persons spirit.
For the last 10 years, I have only been training for 1 year,
Since my body was well used to training, I was gained alot, but then life set in again… Which resulted in the loss of all gained weight and even more so (I fell below my starter weight (it always seems to balance at 82kg) and became scared of what my health might do to me if i do not change it quickly.
I am now beginning a new regime to get back to my comfort zone weight of 92-95kg’s and I am concidering bulking vs or with TRF (due to the seemingly great health benefits, while maintaining a slow, steady growth).
I do see the reason behind bulking first, then adding IF’ as I go along for added benefits, and then going for TRF when my weight is getting better.
BUT, I am also concidering; that the health benefits > musclegrowth due to having had high stress, bad diet, bad sleep, no training (except for some stretching to counteract neck, back, glute, hamstring and achillees problems. (you know, sitting too much infront of a screen with a bad posture)).
Also I need to adress diminishing testosterone, fatigue and really no motivation what so ever to do, well… Pretty much anything…
It has gone so far that I am starting to feel less of a man, and more of a “unisex” or asexual… ofcourse this will have a negative effect on the lovelife, so I really want to “get back to” myself.
So far stretching and finding motivation to do anything about it before it all goes too far, has been my first accomplishment.
Now I need to get back on a slow and steady training/eating/habit to be sure to get enough core strenght, flexibility and well, routines.
So for my questions..
Will bulking for say 3 months (which usually gives me a gain of 16pounds), focusing on eating enough, training enough and rebuilding step by step.
Then going for TRF be advisable?
Or would a TRF regime, with slow but sure gains, managing hormone levels for better mental focus and health as the main goal, then starting bulking say after 3 months (the time it takes for my body to really react to any change), be a “safer route” for me?
I can eat enourmous meals, but usually not too hungry in the morning.
But after I eat the first meal, I can eat pretty much eat every 2nd-3rd hour throughout the day. I need a very high food intake to make gains.
So, are there any suggestions?
I’m more in need of a healthboost than gains (although I want to bulk up to feel better), so what would be advisable?
Best Regards
Hey Eric, I’m sorry to hear about your rough run of luck, man. Props for committing to improve even in the midst of it all. And it sounds like you’re planning on taking a fairly balanced approach to it all, too.
Okay, so, intermittent fasting / time-restricted feeding do alter our hormones, but perhaps not in the way you’re thinking. Intermittent fasting raises cortisol and loweres testosterone overall. This isn’t really a bad thing in the context of general health, but if you’re already concerned that your testosterone is low, that would just make it worse. Being in a calorie surplus (i.e. gaining weight) while having many meals spread throughout the day is what’s going to improve your testosterone.
What I would say is that if you want to build muscle and get your masculine hormones raging again, then go for the bulk. It will take a great deal of effort, but you’ll make tremendous progress, and you’ll feel like a true Beast of a man again. But if you want a break from the effort of it, or if you want to ease into it slowly, then perhaps start with intermittent fasting simply because it’s easier and you like it. Then when you’re ready to step it up, start bulking with more meals spread more evenly throughout the day.
You’ve got a lot of life left. Pick the goal that’s best for you right now.
Even just getting into the habit of lifting again, eating more protein, sleeping better—all of these things will help even if you aren’t doing a dedicated bulk.
I hope that helps, and good luck!
Thank you for your answer! Sometimes you just need some confirmation of being on the right track.
I will be bulking, but first I just got to start moving and I’ll set some alarms to remind me to eat!
Btw. A last question..
What can cause an abdominal muscle to vanish? Leaving almost a dent where it usually bulges out? Only the Muscle on the Upper left side ab, and it happened over night.
Is it pure “body burns muscles if no fat, protein?” thing and will the muscle improve with training? Or might it be some sort of injury?
Thanks!
Hey Eric, did you figure out the mystery of the missing ab, yet? That’s a bizarre case for sure. Not sure what that’s about. It’s not anything to do with burning muscle as a source of energy, though. That would cause you to lose a tiny little itty bit of muscle in a variety of places, not for a particular muscle to vanish into thin air.
[…] guy trying to bulk up, you should be eating more often to help you get calories in. (Check out this intermittent fasting and bulking article on Bony to Beastly for more […]
Well-written site. Thank you!
I’m working out two days a week, lower body on Fridays and upper body on Monday. I’ll start taking my 20 g protein shakes 4 hours before and after my normal meals.
Fasting. I’m considering doing a 36 hour fast once a week, starting after my Tuesday meal. There are some bigs benefits to fasting for this amount of time. I don’t understand how growth hormone works and the benefit of having a huge boost during this period. There are also benefits from authophagy. I’ll experiment and see how my body feels.
[…] If you want to learn more about bulking and intermittent fasting, check out this article that Shane wrote on Bony to Beastly. […]
[…] Intermittent fasting isn’t designed for guys who are trying to bulk up. Even LeanGains isn’t designed for bulking, it’s designed for cutting. If you want to learn more, here’s our full article breaking down the research on whether intermittent fasting is good for…. […]
[…] intermittent fasting is like shooting yourself in the foot. You can read a great article about intermittent fasting and bulking on Bony to Beastly. But, because gaining weight will mean getting into a calorie surplus, and the main benefit of […]
Hi Shane,
First, I’m a total newbie about nutrition, muscle hypertrophy and all this stuff . I was trying to understand how I should spread proteins assumptions through the day and I’ve found out this research article : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3595342/
I don’t have the technical knowledge to evaluate it with a critical eye but it it looks to me that it challenges (maybe only partially) the conclusions of what you called the Nortonian model. You have a lot of personal experience in the field, what is your opinion about it?
Hey Arthur, I think that paper is arguing against the need for equal distribution of protein. An example of equal distribution would be having 60 grams of protein for breakfast, lunch, and dinner day to hit a target of 180 grams.
In this study, they’re saying that if you have a meal with a higher amount of protein, it’s not like that extra protein will got to waste, so you don’t need to worry about keeping that distribution equal. They give the example of having a protein-rich breakfast (e.g. 40 grams), a protein-rich lunch (e.g. 40 grams), and a dinner that’s super high in protein (e.g. 100 grams). In this case, since you’re getting a good muscle-growth response from each meal, it’s fine that the distribution isn’t equal. You’ll still get all the benefits even though the majority of your protein is coming from dinner.
I don’t see any flaw in that line of thinking. That lines up with all of the research I’ve read. We even mention that way of doing it in the article. I think so long as you get 20 grams of protein per meal, you have 3–6 meals (including snacks) per day, and you hit your daily protein target, you’re doing great. I don’t see any problem with eating a ton of protein at dinner to make up for other meals that only have a moderate amount of protein in them.
I don’t think this makes a case for skipping meals entirely, such as you’d do with intermittent fasting. But again, it’s not like it’s the end of the world if you do, it’s just not ideal.
[…] “Try intermittent fasting.” Huh, and skip breakfast, meaning we need to eat an even bigger lunch and dinner? No thanks. (Here’s our full article about whether intermittent fasting is good for bulking.) […]
[…] Eat protein 4–5 times per day. Eating 20+ grams of protein will boost muscle growth for several hours . If you eat protein-rich meals 4–5 times per day, you’ll be building muscle at an accelerated pace all day long. We explain all of this in our article about why intermittent fasting is bad for bulking. […]
[…] build more muscle more leanly. It also helps to have at least 20 grams of protein with each meal, and to have 3–5 meals each day. Milk can definitely help you boost your protein intake higher. Low-fat milk is higher in protein […]
[…] the opposite of what you’ll want to do as an ectomorph trying to build muscle. Here’s our article about intermittent fasting for bulking, but long story short, it’s not ideal for building muscle, and it makes it much harder to get […]
[…] diets are associated with weight loss (study). This is the same problem that we see with intermittent fasting and ketogenic diets. People tend to lose weight when they restrict food groups. And obviously, as […]
Shane, many thanks for quality info.
I really struggle to find that perfect balance. I Really believe in the wonders of IF, but I’m at the point of saying 14 hours fasting every day and no more. I would really appreciate you gut feel opinion please.
My problem is I’m very skinny, but healthy, and prediabetic, so I went Keto route to keep my bloodsugars/insulin down.
But I’m most days struggling with energy. I’m not even trying to bulk. I just want my energy back.
So it’s about balancing low carbs and some IF, with adding some energy and weight… heck I battle to find that sweet spot man!
I MUST go low carbs for my BS
I WANT to do IF, even just 12hours a day
I’m not even worried being skinny, (though I’d love to add some fat/muscle) but hell, energy is non negotiable.
Thank you.
[…] you can lose up to a found of fat per week simply by skipping breakfast. Because of this, intermittent fasting tends to be bad for guys who are trying to gain weight, but great for guys who are trying to lose […]
[…] period is thought to be a way to stimulate muscle growth without breaking the fast. However, intermittent fasting makes it harder to gain weight, so it’s the same issue all over […]
[…] Whenever I would try to eat more calories, I always felt bloated, sick, and lethargic for hours afterwards. Worse still, after a few weeks of trying to eat more, I started getting acid reflux. My stomach just wasn’t big enough to handle large meals. (I made this issue worse by trying to bulk while intermittent fasting.) […]
Hey Shane! Great article, I love your site it has helped me tonne!
There has something that has been going through my mind for a couple of days now: can you get an approach that is best of both worlds?
For example, today I though I would try out:
– Breakfast at 9am
– Workout
– Protein shake + meal at 12pm
– Lunch at 3:30 pm
– Dinner at 6:30 pm
That way you have the benefits that come from aligning your eating window to the day/night cycle and therefore your circadian rhythm but you still have quite a few meals per day. I sleep like 10 hours a day on average.
I’d love to know your opinion on this!
Great article!
I have a question about the “4 hour” muscle protein synthesis.
“If we eat meals more frequently than that, again, the protein will contribute towards our daily macros, but the meals won’t stimulate extra growth via muscle-protein synthesis. ”
Can you hit the optimal growth with 5 meals a day and a 3 hour break between them? Or is it better to eat less meals with at least a 4 hour break between them?
I want to eat like this:
08:30 1st meal
12:00 2nd meal
15:00 3rd meal
18:00 4rd meal
19:00 gymtime
20:30 / 21:00 last meal
Looking forward to hear from you!
It’s technically better to give you body a bit of time to digest and reset before eating another meal, but 3 hours should be about long enough for that. I think you’ll do fine with the extra meals 🙂
Brilliant article, always science-based and pragmatic. Instead of a protein bar, I have a casein protein shake for breakfast, then much later a very light lunch (I’ve found that lunch saps my energy much more than a big breakfast, so I’d love to be able to skip it, then a big dinner (plus some after-dinner snacks).
I think a casein protein shake is great for substituting breakfast.
Thank you, Giovanni! 🙂
Casein can be super handy to have around, yeah. I’ve been having it with some oatmeal and greek yogurt before bed 🙂
Hey! When I clicked on this article I thought I’d never read it completely. But I did. It was extremely good and thanks for that. I was wondering If I could bulk with intermittent fasting, because I really like big meals in order to be more satiated.
However, reading your article, based on the studies, I prefer to optimize muscle growth but make a balance between lifestyle and that growth. So, I have been having a tuna can with some vegetables, which is a bit more than 100 calories with a good intake of protein (26 grams). Then I have 2500-2600 calories for the rest of the day. Is that a good idea? Or could you suggest a better diet?
Thank you very much. My English was probably not the best to read. Greetings from Venezuela 😉
Hey Kevin, greetings from Mexico!
Yes, you can bulk while intermittent fasting. Is it absolutely optimal? Probably not. But even if it’s not, it’s not a huge disadvantage, and it may not even be noticeable. Plus, if you’re having a decent serving of protein along with some vegetables for breakfast, then you’ve solved that problem entirely, and you CAN expect optimal growth. That sounds like a perfect solution.
The problem that a lot of naturally skinny guys run into when trying to bulk while intermittent fasting is that it becomes hard to get into a calorie surplus, but if you aren’t having that problem, then no worries 🙂
Hi Shane. What would you recommend as a more optimal feeding schedule if you’re trying to build muscle without gaining fat:
Option 1 (16:8 fasting):
1pm – Lunch (30g of protein)
3:30pm – Snack (24g of protein)
5pm – Workout (M,W,Fri only)
6pm – Snack (52g of protein)
8pm – Dinner (45g of protein)
9pm – Snack (13g of protein)
Option 2 (no fasting):
11am – Breakfast (24g protein)
1pm – Lunch (30g of protein)
5pm – Workout (M,W,Fri only)
6pm – Snack (52g of protein)
8pm – Dinner (45g of protein)
9pm – Snack (13g of protein)
The caloric and protein intake for both options is exactly the same, and the goal is to make lean gains. I would be eating at a caloric surplus that results in approximately 1 added pound per week. Thanks!
Hey XM, given the current research, we don’t really see any benefit to intermittent fasting for lean muscle growth when in a calorie surplus, so I’d imagine that the second option would be slightly better, given that the protein distribution is a little wider. With that said, I think the difference would be negligible, so and both sound perfectly fine. If it were me, I’d pick based on personal preference instead 🙂
Thanks Shane, that’s what I figured. 🙂
After reading this I now wonder… Let’s say you have only protein shake(s) for ‘breakfast’ and you do all of your day’s cardio before your first real meal of the day(lunch)… Would your body still be in “fat burning” mode while also building muscle?
I mean like, if I drink 2x protein shakes while literally briskly walking on a treadmill for 2 hours (drink while walking at the same time) – you’d consume like 220’ish calories(54g of protein).. Would your body be burning fat from the cardio and also building muscle from last night’s lifting session + the protein you’re giving it now, at the same time??
Hey Adawg, that’s a good question.
It doesn’t seem like there’s really much fat burning benefit to doing fasted cardio. It’s true that you might burn more fat in the moment, burning it for energy as you do go on your walk, but it will balance out again later when you inevitably go back to eating. It’s the same as if you go into a calorie deficit overnight, burning fat, and then go into a calorie surplus again during the day, gaining it back. So if we compare longer term changes in body composition, adding up the results of a few weeks of doing fasted cardio, there’s no extra fat loss overall.
So I wouldn’t think there’s really any downside at all to having some protein before doing your cardio. It shouldn’t affect fat loss at all. And you’ll get that extra spike of muscle-protein synthesis. You’ll build a bit more muscle.
Really great blog and content! Love it. What about the carbs ratio? Are they really necessary for bulking? Can keto or low carb produce similar gains when caloric surplus is the same?
I can’t eat 40-50% carbs for 3200+ kcal. I will be super dizzy. It is impossible for me to get any work done during the day and be focused.
Thought about eating some carbs near evening workouts and otherwise very minimal. Not sure how much this affects bulking.
PS I don’t have any issues going over 3200kcal on low carb. I read that this is the main issue why most fail to bulk. I can probably do 10-20% carb on those calories but no more.
Or maybe 30%
20% carbs is probably enough to get you many of the benefits of eating carbs. With 30%, you’re getting almost all of the benefits. Most bodybuilders get more like 50–60% of their calories from carbs, but they’re deep into the law of diminishing returns by then. If you’re getting 30% of your calories from carbs, I suspect your results will be damn near ideal.
Hey Siim, thank you so much!
How important are carbs while bulking? We’ve got an article on carbs here.
Are ketogenic diets good for building muscle? We’ve got another article on keto here.
I’m not sure why carbs are giving you a bad reaction. Where are you getting your carbs from? Maybe if you switch to more fibrous carbs, such as fruits and legumes, that would do the trick. Or maybe not. I’m not sure what’s going on there.
Personally, I feel bad when I eat a high-fat diet. Many people don’t. There’s some individual variation there. Plus, we adapt to digest the diets we’re used to eating.
You’re right. The main problem with trying to bulk on a ketogenic diet and/or while intermittent fasting is that it’s hard to get into a comfortable calorie surplus. If you can get into a calorie surplus, you’ll be able to gain weight. And if you’re gaining weight, you’ll be able to consistently build muscle.
One potential problem is that dietary fat is easily stored as body fat. It’s also true that when you eat more fat, you burn more fat. So it all comes down to whether you’re in a surplus or a deficit. In a deficit, you’ll burn more fat than you store. In a surplus, though, high-fat diets cause us to store the surplus dietary fat as body fat. It’s not a huge effect, and you’ll still do great, but it’s worth mentioning. Worst case, you just burn the small amount of extra fat off afterwards.
Another potential problem is the lack of glycogen. When we eat more carbs and calories, our muscles inflate with glycogen—with the glucose from the carbs we eat. This makes our muscles look fuller and harder, but the real benefit is that glycogen is fuel. The more glycogen we have in our muscles, the more fuel we have for our training. Not having a lot of glycogen isn’t a big deal with low-rep powerlifting, since you aren’t doing very many reps, but when you’re doing moderate-rep bodybuilding workouts, it really pays to have more glycogen. Plus, having more glycogen in your muscles also directly speeds up your rate of muscle growth. But again, it’s a relatively small effect. You’ll do fine.
Finally, carbs often come packaged with fibre. Fibre is super healthy. It’s great for our blood lipids and digestive health. Mind you, you could eat fibrous carbs that aren’t high in calories—carbs like spinach, broccoli, peppers, and so on.
So to make a long story short, carbs definitely help with muscle growth. But if you don’t handle carbs well, no problem. Eat the amount of carbs that suits you best. You can still get great results.