Illustration of a beginner bodybuilder suffering from bloating and indigestion.

How to Fix Bloating & Indigestion While Eating A Bulking Diet

When I first started weight training and eating for muscle growth, I expected to have more energy, to become stronger, and to look better. But the first thing I noticed was that my stomach started to bloat up like a blowfish. It wasn’t fat, either. I still had abs. But instead of having a flat, washboard stomach, it was curved outwards like a turtle shell.

As I continued to pound down the calories, I started feeling perpetually full, bloated, and gassy. I’d often get indigestion, I struggled with acid reflux, and sometimes I’d even get diarrhea. Something wasn’t going right, but I didn’t know what it was.

I considered going back to my old diet, but that would mean going back to being skinny, and there was no way I was doing that. Fortunately, I realized that this was a fairly common issue with bodybuilders, and that there were a few good ways to improve digestion. Now, even after gaining 65 pounds, it’s easy for me to get into a comfortable calorie surplus.

So, what’s the best way to fix bloating, gas, indigestion, and acid reflux while building muscle?

Illustration of a skinny-fat man becoming lean and muscular.

Why Is It Hard to Digest Food?

We specialize in helping skinny guys build muscle, which means gaining weight, which means eating more calories—more food. And that extra food can cause problems: bloating, indigestion, gas, and sometimes even diarrhea.

Illustration of the stomach size variation between skinny and overweight people.

One of the reasons why most skinny guys have trouble with traditional bodybuilding diets is because our stomachs are often smaller than average. If you’re a so-called “ectomorph,” with a thinner frame and a shallower ribcage, that means there’s less room for your stomach. If we compare that against the average man, not only does he have more room in his torso for his stomach, but he also has a history of overeating, which can stretch his stomach, making it bigger.

To make matters even more complicated, skinny guys are often “hardgainers,” in the sense that our metabolisms are more adaptive than normal. What happens is that we fidget more, move more, and burn off more energy as heat (study). It’s totally subconscious. We don’t even realize that we’re doing it. But it can burn off as much as 950 extra calories per day:

Graph showing that some people burn more calories that others because of their metabolisms.

So we have a situation where some skinny guys have more meagre appetites, smaller stomachs, and faster metabolisms. But because we’re trying to gain weight, we need to find a way to eat more food. So we shovel mountains of food down, and we wind up feeling bloated and cramped, and we struggle with acid reflux and indigestion.

To be clear, running into digestion problems is common with all bodybuilders. Eating a lot of food is hard. But it can be especially hard for skinny guys who are just getting started. We often find ourselves looking pregnant after eating a big bulking meal.

So, how do you get rid of the bloating and indigestion?

The Problem With Bodybuilding Meal Plans

It’s common for skinny beginners to want to change everything all at once. We’re tired of being skinny, we know we’re doing something wrong, and so we want to completely overhaul our exercise routine, diet, and lifestyle. And I get that. I was the same way. During my first bulking attempt, I cut out all of the junk food I was eating, and I replaced it with a stock bulking diet that I found in a bodybuilding magazine.

Illustration of a skinny hardgainer eating a feast in his attempt to bulk up, gain weight. and build muscle.

Overnight, I changed every single meal I ate. I swapped out all of the foods I was eating with somebody else’s diet. And my stomach didn’t like it. I got bloated, I struggled to digest the food, and I started having acid reflux. And I couldn’t figure out why. I was eating the perfect bodybuilding diet, wasn’t I? What was I doing wrong?

The problem is, we all have slightly different digestive systems. We all get used to eating different foods and digesting different foods. We have different gut bacteria, we have different intolerances, and we get used to digesting different ratios of protein, carbs, and fat.

Here are some common examples:

  • If you started eating a ketogenic diet, you’d go through something called the “keto flu,” where you feel awful as your body adapts to getting more of its energy from fat. Keto isn’t good for building muscle, so that isn’t a concern for us, but it goes to show that it takes some time to adapt to different diets.
  • If you started intermittent fasting, you’d probably find yourself really hungry during the morning, struggling with cravings. And then when it’s finally time to eat, you might find yourself eating too much too fast, and running into digestion problems because of it. Again, intermittent fasting isn’t good for building muscle, but this is an example of how changing our meal schedule can cause problems.
  • If you start drinking more milk, that’s great. Drinking more milk is a great way to get more calories, get more protein, and gain weight. However, to digest milk, we need a digestive enzyme called lactase. This is an enzyme that most people can produce themselves, but if you start drinking an extra litre of milk every day, you might not have enough of it! Over time, your body will adapt. You’ll produce more lactase. But jumping straight into it can cause digestive problems.
  • If you start eating bigger meals, again, that’s great. Eating bigger meals is a good way to eat more calories. The problem is, if your stomach is still small, those bigger meals might not fit. You might find that you have trouble digesting those meals, making you feel tired for several hours afterwards. You may even get acid reflux. And that’s normal. Most people feel that way after Christmas or Thanksgiving dinner, when they eat an abnormally large amount of food. But you may find it more enjoyable to eat smaller meals more often. Instead of eating bigger meals, eat more snacks.
  • If you start eating more fruits, veggies, legumes, and grains, that means you’ll be eating more fibre. And fibre is great. It’s healthy. It’s good for your digestive system. But it’s possible to get too much of a good thing. Eating 30 grams of fibre per day is great, but what about eating 60 grams? What about 90 grams? For most of us, that’s too much. It’s too hard to digest. That’s why so many bodybuilders bulk on white rice instead of brown rice. It’s not that white rice is “healthier,” it’s just that white rice is lower in fibre, and so it causes fewer digestive issues.

Most of these digestion issues are caused by changing our diets too much too soon. We’re eating enormous meals before our stomachs have expanded enough to be able to hold them. We’re drinking too much milk before we’re producing the digestive enzymes we need to digest it. We’re changing where where we get our energy before our body has adapted to it. And we’re eating too much fibre all of us a sudden, before the bacteria in our stomach can learn to manage it.

The absolute worst way to approach a bulking diet, then, is to start copying some bodybuilder’s meal plan. You’ll be abandoning all of the foods that you’re good at digesting, replacing them with foods you don’t know how to digest. You’ll be abandoning the schedule that your body has acclimatized to, replacing it with a schedule that you aren’t prepared for. This can affect us in a variety of ways, ranging from bloating to gas to indigestion, and it can even make us wake up in the middle of the night needing to pee.

The best way to build a bulking diet, then, is to gradually change your current diet.

How to Digest Food More Easily While Bulking

When we start eating for muscle growth, we want to build on our current diet, making strategic changes gradually. Here are some good ways to approach it:

  • Increase your calorie intake by making your meals a little bit bigger, and by adding foods that are easy to digest, such as white rice or bananas.
  • If you need even more calories, try adding snacks. And again, choose snacks are easy to digest. Trail mix often works well, especially if you choose trail mix made out of foods that you enjoy. (I use a mix of peanuts, almonds, cranberries, and raisins.)
  • Keep eating the good foods that you already eat. If you enjoy eating tortilla, you don’t need to swap them out for potatoes. If you’re eating potatoes, you don’t need to swap them out for rice. You can keep eating the foods you’re already eating.
  • Choose foods that are easy to digest. If steak is hard to digest, try eating ground meat instead. It’s equally nutritious, but the grinding will make it easier to chew and digest. If you’re using protein powder, whey is often easiest to digest (unless you have trouble digesting dairy).
  • When adding in foods, be careful with fibre. If you’re adding carbs to meal, consider low-fibre options like white rice or white pasta. If you’re making a workout shake or mass gainer, use maltodextrin instead of ground oats.
  • Add in foods that improve digestion, such as yoghurt, hard cheeses, bananas, and onions. But again, add these foods in little by little.
  • Be careful with fad diets. It’s usually better to avoid pop culture diets, such as keto, paleo, and intermittent fasting. It’s not that these diets are bad, it’s just that they aren’t designed for helping people build muscle or gain weight. They’re designed for weight loss. That’s the opposite goal.
  • Don’t be too extreme. It’s common for skinny guys to start drinking a gallon of milk per day, or chugging 5 raw eggs every morning, or taking shots of olive oil, or chugging pre-workouts full of stimulants before their workouts. That’s usually a bad idea. There’s nothing wrong with milk, eggs, olive oil, or pre-workouts, but ease into it more gradually. Don’t be so extreme with it. Start with a glass of milk with meals, eating 2–3 eggs per day, drizzling olive oil on your vegetables, and drinking a cup of coffee before working out. It’s less exciting, but your digestive system might thank you for it.
  • Avoid intolerances. Some people are allergic to eggs, have trouble digesting gluten, or can’t produce enough lactase to digest milk very well. The problem is, you might not know what your allergies and intolerances are. That’s another reason why bulking might not be the best time to completely change your diet. You might run into foods that disagree with you, and it will be hard to figure out what they are.
  • Go on a walk after eating. A good way to get your digestive system moving is to get up and go on a walk after eating a big meal. It doesn’t need to be a long walk, and you don’t need to do it after every meal, but if you’ve eaten so much that you want to lie down, it might be best to stand up instead.

Oh, and there’s nothing wrong with having 2–3 scoops of whey protein every day if you’re having trouble hitting your daily protein goals. But if you start getting diarrhea, that might be why! That’s often the first sign that you’re overdoing it on the whey protein. So if that happens, diversify your protein sources. Try getting your protein from meat, fish, milk, eggs, legumes, or even from other protein powders.


It’s common for skinny guys to run into trouble when they first start eating a bulking diet. This is something that most bodybuilders struggle with. It’s hard to digest a lot of calories. But even so, there are some things we can do to make it much easier.

There are a lot of tricks, and we’ve covered them above, but most of it boils down to changing your diet gradually, avoiding abnormally large meals, getting more of your calories from snacks, and being mindful of overdoing your fibre intake.

Before/after photo of Shane Duquette starting skinny, bulking up, and building muscle.
Shane Duquette, 130 pounds (left) and 195 pounds (right).

When I first started building muscle, my bulking diet was giving me a lot of grief. But over time, my stomach got bigger, my digestion system got stronger, and I started being able to digest a wider variety of foods more easily. We just have to be patient with it.

Shane Duquette is the co-founder and creative lead of Outlift, Bony to Beastly, and Bony to Bombshell, and has a degree in design from York University in Toronto, Canada. He's personally gained sixty pounds at 11% body fat and has nine years of experience helping over ten thousand skinny people bulk up.