Most ectomorphs have trouble eating enough calories to gain weight. There’s a good reason for that, too: we have faster metabolisms and smaller stomachs. Unfortunately, the only way to gain weight is to get into a calorie surplus. I know that’s a tough bite to swallow, especially if you’re already stuffed to the gills, but there’s no way around it.
To make matters harder still, we aren’t just trying to gain weight, we’re trying to build muscle. That adds a few other considerations.
So what we want to do is design a diet around calorie-rich foods that improve our digestion and make it easier to build muscle quickly and leanly.
Let’s call this diet the Ectomorph Bulking Diet.
- Will This Diet Help You Gain Weight?
- Pillar #1: Don’t Shoot Yourself in The Stomach
- Pillar #2: Make Your Diet Less Filling
- Pillar #3: Eat More Snacks
- Pillar #4: Make Your Diet Easier to Digest
- The Ectomorph Bulking Diet
Will This Diet Help You Gain Weight?
I know how hard it can be to gain weight. I spent years trying to bulk up before I finally managed to budge the scale. So before we dive deeper, let me explain why I’m so confident that these principles will actually help you gain weight:
- They’re evidence-based: This diet is based on all of the best research looking into appetite, digestion, weight gain, and muscle growth.
- They’re time-tested: These are the same techniques that we use in our Bony to Beastly Bulking Program, which has helped nearly 10,000 naturally skinny guys bulk up.
- We’ve used them at the highest level: We’ve used this same diet to help professional and Olympic athletes bulk up; to help doctors and dieticians bulk up.
- We’re skinny guys, too: We’re naturally skinny guys ourselves, we had a brutal time gaining weight, and this is what finally allowed us to bulk up. I’ve personally used this weight-gain diet to gain 55 pounds in just a couple years, finishing visibly leaner than when I started:
Pillar #1: Don’t Shoot Yourself in The Stomach
To start things off, we need to learn the difference between a weight-loss diet and a bulking diet. Most people are overweight, and so most diets are built with weight loss in mind. That means that the very first step is to make sure that you aren’t accidentally following weight-loss advice—to make sure that you aren’t shooting yourself in the stomach, so to speak.
For example, in most bodybuilding communities, there’s a big emphasis on lifting weights, eating lots of protein, and eating “clean.” Clean is a vague term that can mean a variety of things: avoiding carbs, avoiding sugar, avoiding junk food, avoiding gluten, etc. We’ve got a full article about the pros and cons of clean and dirty bulking.
Generally, the foods that are being restricted are the foods that are higher in calories—the foods that are easier to overeat. Restricting these foods makes it easier for people to lose weight, which is why these diets have gained mainstream popularity. These are weight-loss diets.
Weight-Loss Diets Masquerading as Bulking Diets
To illustrate this example, let’s consider intermittent fasting, where you restrict the number of meals you eat. The most popular form of intermittent fasting is where you skip breakfast, eating just lunch and dinner. This approach was popularized by Martin Berkhan, who dubbed it LeanGains. It was then further popularized by guys like Greg O’Gallagher (from Kinobody).
If we look at the research on appetite, such as this 2014 study on meal frequency, it shows that the more meals the participants ate, the more weight they gained. This tells us that if we’re trying to gain weight, we should be adding snacks into our diets, not removing meals. Intermittent fasting isn’t a magic diet, it just makes it harder for us to gain weight.
That raises the question, then: why is the most popular type of intermittent fasting called LeanGains? I suspect it’s because intermittent fasting is a weight-loss diet that’s being marketed towards guys who want to be lean and muscular. However, make no mistake: it’s still a weight-loss diet.
The same is true with the ketogenic diet. In theory, it’s possible to bulk up on a ketogenic diet, but when researchers tried to study it, they found that the participants weren’t even able to get into a calorie surplus.
Plant-based diets are associated with weight loss, too. It’s certainly possible to bulk on a vegan diet, but when people switch over to a plant-based diet, they tend to inadvertently lose weight.
Are Restrictive Bulking Diets Healthier?
Many popular diets are good for improving the average person’s health. There’s an important caveat to that, though: these diets are good for our health in the same way that losing weight is good for our health.
Most people are overweight. So for most people, losing weight is healthy. However, given that we’re skinny, that stops being the case. Our circumstances call for something different.
There’s nothing inherently unhealthy about breakfast, carbs, grains, or even a modest amount of sugar. The only “unhealthy” thing about them is that they make it easier to eat more calories, causing people to accidentally gain weight.
However, since skinny guys tend to benefit from gaining weight, diets that make it easier to eat more calories are often better for our health. Once we understand that, we can relax on the restrictions, eat a wider variety of foods, and have a far easier time bulking up.
Lightning summary: it’s important to eat a healthy diet that’s centred around whole foods, but if as skinny guys who are trying to bulk up, it’s usually better to think about adding in more good foods, not removing the bad foods.
By focusing on adding more high-calorie whole foods into our diets, we can add in more vitamins, minerals, phytonutrients, and protein, and we can do it in a way that also helps us gain weight.
Pillar #2: Make Your Diet Less Filling
After we’ve removed any unnecessary dietary restrictions, the next thing we want to do is add in energy-dense foods that will help us gain weight. More specifically, we’re looking for foods that are:
- Easy on our appetites
- Good for our health
- Great for building muscle
- Less likely to be stored as body fat
To start, we can use The Satiety Index of Common Foods. In this study, they took a sampling of common foods, figured out how filling they were, and then observed how food choices impacted our overall calorie intake.
The goal of the study, as you can probably guess, was to help people feel more satisfied while eating fewer calories. We’re going to use it for the opposite purpose: to find out how to eat more calories.
I’ve organized the foods into categories and remade their results graph:
Most of the results are fairly intuitive. Whole foods are filling, and then the more you process them—removing fibre, removing water, and breaking them down into smaller particles—the less filling they become. This explains how junk food contributes to obesity: it delivers calories too efficiently. No huge surprise there.
But some of these results are weird. I never would have guessed that potatoes were the best weight-loss food ever. They’re 300% more filling than bananas and 700% more filling than croissants. Mind you, “steak and potatoes” is an expression that means simple yet filling, so I shouldn’t have been too surprised to find that both steak and potatoes are indeed simple yet filling.
However, keep in mind that the preparation of the food matters. They studied boiled potatoes. Boiled potatoes are fairly low in calories and fairly high in water content. If we made homefries, cutting those potatoes up into wedges, coated them in olive oil, and then baked out some of the water, we’d be adding more healthy calories while making the potatoes less filling per calorie. This would make it easier to gain weight.
We can prepare steak in a way that’s less filling, too. But first we need to find out why steak is so filling in the first place. More on that in a second.
Does satiety actually affect how many calories we eat? The researchers found that with these 250-calorie meals, for every 100-point difference on the satiety scale, there was a corresponding 50-calorie difference in how much was eaten in the next meal. That means that if you ate a potato for lunch (323 satiety), you’d eat a 650-calorie dinner. On the other hand, if you ate a croissant for lunch (47 satiety), then you’d eat an 800-calorie dinner.
If you eat three meals per day, these simple food choices yield a difference of 450 calories. That’s enough to bulk up. In fact, that’s enough of a calorie surplus to bulk quite quickly, gaining nearly a pound per week. Best of all, we’d be bulking without needing to force-feed ourselves.
The trick is, we can’t just haphazardly eat more processed foods. That would allow us to gain weight, sure, but it wouldn’t be an effective way to gain muscle quickly and leanly. Processed food, especially if it’s high in saturated fat and fructose, can reduce muscle growth and increase fat storage (study).
Besides, most of us who are trying to get bigger want to do it in a way that has a positive effect on our health. So we need to make sure that we’re eating a diet that’s promoting muscle gain, not fat gain.
Why Are Some Foods More Filling Than Others?
The researchers concluded that the most filling foods were either high in protein (like chicken breast), high in fibre (like broccoli), or high in water (like boiled potatoes).
If we look at research conducted since then, we can also see that foods that are harder to chew are more filling. This means that a tough steak is more filling than ground meat, and overcooked chicken breast is more filling than shredded chicken.
Even better if you don’t need to chew the food at all—such as with milk, fruit juice, smoothies, and protein shakes. In that case, your body barely even realizes that you’re consuming calories at all. This is one of the reasons why milk is so good for helping people bulk up.
Flavour is also an important factor, as explained in books like The Dorito Effect. After all, part of the reason that we eat more calories is that we enjoy eating those extra calories.
The Five Factors That Make Food More Filling
So far, researchers have found five factors that make food more filling:
- High protein content (like chicken breast).
- High fibre content (like broccoli).
- High water content (like potatoes).
- It’s hard to chew (like tough steak).
- It doesn’t taste good (like plain chicken breast).
Some foods are a perfect storm. They’re low in protein, low in fibre, easy to chew, intensely flavourful, and don’t have much water in them. Dorito chips are a good example of that.
The problem is that Doritos aren’t very good for building muscle. They don’t have enough vitamins and minerals, they’re too low in protein, they’re too low in fibre, they’re too high in processed fat, and they’re bad for our digestive systems if we have too many of them.
We need to find foods that make it easier to eat more calories that are still good for gaining muscle.
How to Make Protein Less Filling
If you look at lean fish, steak, and chicken breast, you get protein sources that are hard to chew and slow to digest, making them almost impossible to bulk up with. That still leaves us with a few ways to eat more protein without ruining our appetite:
- Choose liquid protein sources, such as whey protein shakes, yogurt, or milk.
- Choose high-calorie protein sources, such as salmon or chicken thighs, which are high in protein while also being high in healthy fat, raising their overall calorie content.
- Cook the meat in a way that makes it easier to chew and quicker to digest. One example of this is stewing the meat until it falls apart on your fork. Another example is to choose ground meat instead of steak. This is why foods like hamburgers, chili, and picadillo can be great for bulking.
How to Make Fibre less Filling
First of all, you don’t need to be eating that much fibre, especially when bulking up. Experts like Eric Helms, PhD, recommend getting around ten grams of fibre for every thousand calories.
For example, if you’re bulking up on 3000 calories per day, you only need about thirty grams of fibre. That’s not very much fibre, and eating more fibre than that can begin to put a strain on your digestive system, given the sheer volume of food that you’re eating.
Here are some tips to keep your diet healthy while reducing your fibre intake:
- White foods are okay. For example, brown rice is usually marketed as being healthier because of its higher fibre content. However, white rice is cheaper, less filling, quicker to prepare, easier to digest, and, yes, lower in fibre (which in this case is a good thing).
- Eat fruits instead of vegetables. Vegetables have a reputation for being healthier than fruits, but that’s a myth. Fruits and vegetables are actually both equally healthy sources of fibre and phytonutrients. The only “downside” to fruits is that they’re higher in calories and natural sugars, making it easier to gain weight. These natural sugars are contained within plant cells, and so they don’t tend to have any negative impact on our health. You could say that vegetables are healthier for overweight people, whereas fruits are healthier for underweight people.
- Blend the foods that are higher in fibre. Leafy greens are great for your health. No getting around that. The problem is that they’re also incredibly filling. They take a lot of effort to chew, and they’re made up almost entirely of fibre and water, which won’t get you any closer to your calorie goals. So blend them. They’ll be pulverized into perfectly “chewed” particles, taking up far less space in your stomach and digesting far more quickly.
How to Make Water Less Filling
A 12-week study looking into water intake and digestion found that people who drank a glass of water with their meals inadvertently wound up losing 4.4 pounds more than the control group. Not quite the effect we’re going for.
However, a recent systematic review found that people who drank milk, fruit juice, or other sugary drinks wound up consuming 8–15% more calories overall. For the average person eating a 2500-calorie diet, that amounts to an extra 200–375 calories per day. That’s enough to gain more than half a pound per week.
If you’re feeling thirsty during a meal, I’d recommend having some milk or cranberry juice instead. That way the fluid you’re drinking is smuggling in some calories along with the water.
The next thing to consider is watery foods. For example, soup is notorious for being incredibly filling despite being extremely low in calories. For another example, if you compare a grape with a raisin, it becomes obvious that 90% of its volume comes from water.
- Don’t fill up on fluids. Have your water between meals instead of with meals. Or, if you like having water with meals, try having milk or cranberry juice instead.
- Dried fruits are far less filling than regular fruits. If you take a grape and remove the water, you’re left with a raisin that’s 1/10th the size and yet still contains the exact same nutrients and calories. Prunes, dates, and dried mangoes are also great for bulking up.
- Most fluids are hydrating. Keep in mind that most fluids, and even many foods, contain plenty of water. That water is still hydrating. So long as your pee isn’t darker than straw, there’s probably enough water in your diet.
How to Make Food Easier to Chew
The easiest way to make food easier to chew is to blend it. That doesn’t mean that you should blend everything, but it does mean that a morning smoothie might make for a good start to your day.
- Blend up fruits with yogurt, milk, or protein powder. You’ll get all the same nutrients, but they’ll be far less filling.
- Choose ground meat instead of steak. This is the same idea as blending up your fruits, except instead of blending chewy fruit into a smoothie, you’re grinding chewy meat into a hamburger patty or chili. Some bulkers just mix ground meat with some rice and veggies, throw some hamburger helper into it, and call it a meal. Not a bad idea.
- Cook your food well. Cooked carrots are easier to chew than raw carrots, (properly) stewed beef is easier to chew than steak, and kale chips are easier to eat than a kale salad. Cooking is also a form of healthy processing that will help your body digest the food more easily, allowing you to extract more calories from it with less of a strain on your digestive system.
How to Leverage the Buffet Effect
The buffet effect the phenomenon where people tend to eat more calories when they have access to a greater variety of foods and flavours. A common example of this is when someone stops eating dinner because they feel full, but then they magically find space in their stomach for dessert (study, study, study).
The reason behind this effect is that our bodies naturally crave a varied intake of nutrients from a number of different sources. Perhaps the dinner you’re eating is rich in iron but low in vitamin C, so when you’re presented with a fruity dessert, your stomach is eager to find extra room for it.
If you’re binging on junk food, the buffet effect can be a real problem, which is why it’s being studied. Switching from salty chips to sweet soda will activate this effect, causing people to overeat, but without providing their bodies with the nutrients that they need.
When bulking, though, we can switch between different nutritious foods. This will not only help us eat more calories, but it will also help to prevent nutrient deficiencies.
- Use sauces and spices liberally. There’s nothing wrong with using plenty of barbecue sauce, ketchup, mustard, hot sauce, soy sauce, salt, pepper, onion powder, garlic powder, and whatever else you enjoy using on your foods. Some of them contain calories (often coming from sugar), but that just boosts the calorie content of your food without removing any of the vitamins, minerals and fibre in it.
- Vary the flavours in your food. It’s easiest to bulk up when your meals are fairly consistent, but your body will burn out on certain flavours if you eat them over and over again. So try to add variety via spices, sauces, and toppings. For example, my wife and I will have picadillo served on tortillas one day (as tacos) with plenty of hot sauce, then picadillo served on a bed of rice the next day with a little bit of soy sauce (which tastes better than it sounds). This allows us to make a giant pot of picadillo that we eat all week long without feeling like we’re eating the same thing every day.
- Combine smaller meals into one mega-meal. When doing his Geek to Freak muscle-building experiment, Tim Ferriss famously bulked up on chili served on a bed of macaroni and cheese. A bizarre combination, but one that helped him prevent flavour fatigue. A more common example of this would be to have dinner (e.g. stew) served alongside a drink (e.g. cranberry juice) followed by a dessert (e.g. ice cream). Yes, these larger meals will take a while to digest, but if you have them at night, your body can digest them while you sleep.
Lightning summary: Now’s not the time to be loading up on raw low-calorie watery fibrous foods like broccoli, lettuce, and watermelon. Go for the higher calorie choices instead, such as hamburgers, bananas, milk and trail mix. They’re often just as healthy while being far less filling.
The Best Bulking Foods
We’ve got a full article doing in-depth on the very best bulking foods. But here are some quick examples of nutritious whole foods that also have a high energy density:
- Trail mix
- Dried fruits
- Nuts (and nut butter)
- Muesli cereal
- White rice
- Protein powders
- Milk, yogurt, and cheese
- Olive oil
- Fatty fish (and fish oil)
- Dark chocolate
- Ground meat
Pillar #3: Eat More Snacks
One of the main differences between naturally skinny guys (ectomorphs) and naturally overweight guys (endomorphs) is that our stomachs are much smaller. In fact, our stomachs can be up to 6 times smaller than theirs. This is why they can wolf down giant meals with ease, but if we try to match them fork for fork, we wind up feeling sick and lethargic.
For example, eating meals that are too big for your stomach to handle can increase your risk of getting acid reflux or gastroesophageal reflux disease (GERD). This is especially common with ectomorphs due to our smaller stomachs. And, as you can imagine, bulking diets can exacerbate this issue (study).
When I started experimenting with an intermittent fasting diet, within a couple of weeks I started to get acid reflux, and before long it became full-fledged GERD. When I switched back to eating more frequently, the acid reflux went away over the course of the next couple months.
The good news is that your body does a poor job of tracking how many calories you eat while snacking. This study found that if you have a 300-calorie snack after lunch, you’ll naturally eat around 100 fewer calories for dinner, resulting in an accidental gain of 200 calories with zero stress on your stomach or appetite. Therefore, one of the best ways for ectomorphs to improve their bulking diets is to forget about eating bigger meals and instead focus on snacking between meals. That will not only prevent discomfort but also boost your appetite.
To switch from a maintenance diet into a bulking diet, you only need about 500 extra calories per day. You could do that by adding in a couple of 250-calorie snacks.
There’s another factor to consider as well. Every time you eat a meal that has enough protein in it (at least 20 grams), you’ll stimulate muscle growth. This extra muscle growth will last for a few hours, and then your body will return to normal, at which point you can stimulate muscle growth again by eating another protein-rich meal (study). This means that adding extra snacks into your bulking diet could increase how much muscle you build. And by increasing how much muscle you can build without increasing your overall calorie intake, you’re going to make leaner gains.
Dr Helms estimates that eating 4–5 meals per day, each containing at least 20 grams of protein, is the absolute ideal for building muscle quickly and leanly. Furthermore, it has the added bonus of allowing us to eat more calories more comfortably.
Lightning summary: if you currently eat the standard three meals per day, instead of making those meals bigger, you might want to experiment with adding in a single 500-calorie meal, or adding in a couple 250-calorie snacks.
Pillar #4: Make Your Diet Easier to Digest
One of the main complaints that ectomorphs have is that bulking diets make them tired, bloated, and gassy. Another issue is that a meal might keep us full for hours, making it difficult to eat often enough, and thus causing us to fall behind on our calories. Then, once we fall behind, we’re forced to eat bigger meals. That only makes the discomfort worse.
Eating a diet that’s high in saturated fats, processed foods, and food additives has been linked with digestive issues ranging in severity from mild discomfort all the way up to inflammatory bowel disease (IBD), meaning that it’s important to eat a diet that’s made up mostly of whole foods (study, study).
Aiming to get 80% of your calories from whole foods is a good rule of thumb. That means that it’s probably okay to have some dessert after dinner most nights, and there’s little harm in the occasional pizza. However, your diet should still be made up mostly of whole foods.
So the key to building a good ectomorph bulking diet is to build it mainly out of whole foods, giving us plenty of vitamins, minerals, phytonutrients, prebiotics, and probiotics, but to do so in a way that doesn’t cause too much gas and bloating, and that doesn’t slow our digestion down too much.
Eat a Moderate Amount of Fibre
More often than not, eating more fibre is a good thing. In fact, one of the main benefits to eating whole foods is that they’re high in fibre, which helps your digestive system in a few ways:
- Insoluble fibre acts as a sort of toothbrush, cleaning your digestive tract as it passes through, and keeping everything moving along at a steady pace.
- Fibre is a prebiotic, which means that it feeds the beneficial bacteria in your gut. These beneficial bacteria then help with your digestion.
- Having enough fibre in your bulking diet reduces your risk of developing digestive issues (study).
However, more fibre isn’t always better. There’s a limit to how much we can process before it starts to strain our digestive system. When we raise our intake of whole foods and we start eating an extra 500+ calories every day, we run the risk of driving our fibre intake way too high, which is going to cause the opposite sort of problem, where it takes so much effort to digest the food that our digestive system can’t keep up. After all, one of the benefits of eating unprocessed foods is that they tend to digest most slowly and steadily. For ectomorphs who are trying to eat a bulking diet, that can be a real problem.
A good rule of thumb is to aim for ten grams of fibre per thousand calories, which represents a moderate fibre intake. If your diet is made up of 80% whole foods, there’s a good chance that you’re already at or above that threshold. In that case, you may benefit from getting your extra calories from lower-fibre foods, such as:
- White rice
- Fruit juice
These foods are still nutritious and good for your digestive system, but they’re also fairly low in fibre, which will speed up your digestion and help to reduce bloating and gas.
On the other hand, if your diet is higher in processed foods, you might want to think about adding in foods that are higher in fibre yet still easy to digest, such as:
- Smoothies containing fruits and veggies
- Oatmeal and muesli cereals
- Dried fruits and nuts
- Flax and chia
Eat Plenty of Probiotics and Prebiotics
If you eat a bulking diet that’s made up mostly of whole foods, you’re naturally going to be eating plenty of foods that support strong microflora. Many common cooking ingredients, such as onions and garlic, are great for your immune system and digestive health. Other foods have fibre that feeds your microflora. And some common bulking foods, such as bananas, are great for your digestion.
However, just to make sure that you have the right kind of bacteria in your gut, it’s also a good idea to make a habit of eating fermented foods that have healthy bacteria in them (study), such as:
- Hard cheeses
Eating more of these probiotic sources will help to reduce digestion issues (study, study, study). Hard cheeses, yogurt, and milk-based kefir are also high in calories and high in protein, making them incredible bulking foods. They’re also easy to digest (study, study).
Blend, Grind, and Cook Your Food
Processed food is essentially pre-digested. It’s been ground into a pulp, the fibre has been removed, and it’s been cooked to the point of sterilization. This removes many of the nutrients, which is a problem, but it also makes these foods easy to digest. That’s one of the reasons that processed foods are so easy to overeat—they pass through the digestive system very quickly and easily, allowing us to eat more calories overall.
The problem with a lot of whole foods, then, is that they’re slower and harder to digest. We can fix that, though, and without making our bulking diets any less healthy:
- Choose whole foods that are naturally easier to chew and digest, such as getting our carbs from bananas instead of apples, or from white rice instead of brown rice.
- Cook your food well, such as eating your veggies cooked instead of raw, your meat medium instead of rare.
- Eat ground meat instead of steak, which is just as nutritious but far easier to chew and digest.
- Blend your fruits, veggies, and oats into smoothies.
If all else fails, put more effort into chewing your food before swallowing. The more saliva your food comes into contact with while it’s in your mouth, the sooner it will start digesting. And the smaller you can crush your food before you swallow it, the less work you’re leaving for your digestive system (study).
The Ectomorph Bulking Diet
It’s common for skinny guys to have a hard time gaining weight. Fortunately, if we leverage appetite and satiety research, there are ways that we can make bulking much easier.
Here’s how to eat a good ectomorph bulking diet:
- Stop focusing on cutting bad things out, start focusing on adding good things in. Add foods into your diet that make it easier to gain weight: smoothies, juice, milk, ground meat, nuts, dried fruits, trail mix, protein powder, etc.
- Don’t make your meals bigger, add snacks. If you have a small stomach, eating bigger meals will make you feel bloated and lethargic. Snacking is a much easier way to add calories into your diet.
- Eat calorie-dense foods. Nuts and dried fruits are great for this, making trail mix one of the best bulking foods.
- Eat foods that are lower in fibre. You need fibre in your diet, but it’s also important not to eat too much. 10 grams of fibre per 1000 calories is usually ideal for bulking.
- Blend, grind, and cook your food. The better you can prepare your food, the less work your digestive system will have to do. For example, ground meat and smoothies are essentially pre-chewed, they’re easier to digest, and your digestive system can process them more quickly.
- Drink your calories instead of eating them. Liquid calories are less filling per calorie and clear out your stomach faster. Smoothies, milk, fruit juice, and protein shakes are all great choices while bulking.
- Build a stronger digestive system. Eating plenty of prebiotics and probiotics can improve your ability to digest food. For example, a diet rich in onions, garlic, bananas, and yogurt can make it easier to digest more calories.
- Make your food taste better. The better your food tastes, the more of it you’ll want to eat. One simple trick is to have dessert after dinner. If you want to avoid processed foods, simply have a nutritious dessert.