This bulking diet guide covers everything you need to know about eating for muscle growth. This is how bodybuilders have traditionally bulked up, how athletes gain lean mass, and what modern science shows is the most effective way to fuel muscle growth.
Cassandra used this diet to gain over twenty pounds, I’ve used it to gain over sixty pounds, and Marco used it to gain over seventy. We also use it to help our clients bulk up, both in person and online. Those clients range from desk workers to college, professional, and Olympic athletes.
There are five parts to this guide:
Don’t expect to be shocked or thrilled. There’s nothing controversial here. These are well-known and well-studied principles with decades of tradition behind them. That’s by far the best way to get reliable results.
Table of ContentsThe latest fad diet is exciting because its limits haven’t been found yet. Maybe you’ll build muscle leanly and incredibly quickly. Perhaps you’ll get better results than anyone has ever seen before.
Then, more people try the diet, it gets studied, and we find the limits. Almost always, the diet winds up being slightly less effective than the traditional approach, and it gets washed away by the waves of time. For example, intermittent fasting and ketogenic diets aren’t quite as good as traditional bulking diets.
This article is about the traditional bulking diet:
Muscle-building diets have improved gradually over the years. All of those improvements were brand new at some point. However, these tend to be incremental improvements. A small tweak yields an improvement that’s barely noticeable. Yet, when enough of those small improvements coalesce, you get a diet that’s significantly better for building muscle.
I’m sure we’ve missed some effective methods, but it pays to be patient. For every gem, there are ten pieces of glimmering glass. It’s wiser to wait until the evidence grows strong enough.
As the research currently stands, as of 2024, this should be the best bulking diet.
The most important part of any bulking diet is the calorie surplus. Not everyone needs to get into a surplus to build muscle, but most skinny people, lean people, and intermediate lifters do. That’s who this article is for.
But how big should your calorie surplus be? We have a full article digging into the research, but as a rule of thumb, gaining around a pound per week should allow you to build muscle fairly fast while keeping your gains quite lean (systematic review).
Skinny beginners are often able to build muscle faster. If that’s you, you might be able to gain 1–2 pounds per week without gaining much fat. I gained 20 pounds during my first three months of bulking (1.6 pounds per week). My roommate gained over 2 pounds per week. We see numbers like that all the time with people doing our bulking program:
As you build more muscle, you’ll get closer to your genetic potential, and your rate of muscle growth will slow. So for intermediate lifters who have already gained their first 20 pounds, a better rule of thumb is to gain 0.5–1 pound per week:
Some research shows that even advanced bodybuilders can build muscle faster by gaining weight faster, but that extra muscle usually comes with extra fat (study). So, if you’re at all afraid of gaining fat, it usually pays to take it slower.
Plus, for every study showing a benefit to gaining weight faster, there’s another showing it doesn’t help. We want the best of both worlds: fast muscle growth with minimal fat gain. Gaining 0.5–1 pound per week is usually the best way to do that.
There are three good ways to get into a calorie surplus:
Whichever method you choose, the magic happens when you start making adjustments based on how quickly you’re gaining weight. The sooner you start eating more food and weighing yourself, the sooner you can refine your diet until it’s working perfectly.
Whatever method you choose, adjust your calories based on how much weight you gain each week. For example, if you weigh 150 pounds, you might start by eating 3,000 calories per day. That’s a good place to start, but your metabolism might be faster than average, and you might not gain weight. That doesn’t mean you’re doomed to stay skinny forever; it just means you need to add more calories.
If you’re not gaining weight, add 200 calories. If you’re gaining weight too fast, remove 100 calories. This can be as simple as increasing your serving sizes, eating a handful of trail mix, or having a banana with a glass of milk. If you’re tracking your calories with Macrofactor, it will adjust your recommendations automatically.
There’s a bit of nuance here, though. Your weight fluctuates. You can easily gain a few pounds between breakfast and dinner as your digestive system fills up with food. So, you need to track your weight properly:
You don’t need to track your macros, but it helps to know what they are and what you’re aiming for. If already eat a healthy diet, your macros are probably okay, but you might need some extra protein while bulking. If you’re using our recipes, we’ve already optimized the macros for you. And if you’re using Macrofactor, it will give you targets to aim for.
Food contains nutrients. The nutrients that contain energy are called macronutrients (protein, carbs, fat, and fibre) and the ones that don’t are called micronutrients (vitamins, minerals, probiotics, phytonutrients, etc). You need both of them to be healthy, but it’s the macronutrients that help you gain weight.
A good rule of thumb is to aim for roughly 1 gram of protein per pound of body weight per day. So, if you weigh 150 pounds, aim for around 150 grams of protein per day.
That’s a rough goal, though. The latest research shows that eating as little as 0.7 grams/pound/day is enough to maximize your rate of muscle growth (study). At the other end of the spectrum, Jose Antonio has conducted several studies showing that eating tons of protein is fine but doesn’t speed up muscle growth (study, study, study).
Consuming 5.5 times the recommended daily allowance of protein has no effect on body composition in resistance-trained individuals
Jose Antonio, PhD
We recommend eating a balanced diet made up of balanced meals. That means every meal should have a source of protein in it. A good rule of thumb is to aim for at least 20 grams per meal, but some of your meals will likely need to have more.
The type of protein you eat doesn’t seem to matter. You might hear that some sources of protein are more complete or have more leucine, and that’s true, but these are only concerns for people eating very little protein. Bulking diets have an abundance of protein. You’ll get all the amino acids you need.
You can get your protein from meat, dairy, eggs, nuts, seeds, peas, whole grains, legumes, soy, and whatever else you can think of. You can even bulk on a fully vegan diet (study).
Carbs are controversial, but they shouldn’t be, especially for building muscle. Most of the longest-living cultures eat diets that are over 50% carbs. Elite athletes usually get 50–60% of their calories from carbs. The typical bodybuilder eats a high-carb diet, too.
Still, carbs are often blamed for the obesity epidemic, and there’s a grain of truth there. When researchers remove carbs from people’s diets, they often have a hard time eating enough calories to gain weight. For overweight people, that’s a desirable outcome. But for skinny guys trying to bulk up, it can make gaining weight almost impossible.
A 15-week study split bodybuilders into low-carb and high-carb groups (study). The low-carb group wasn’t able to eat enough calories to support muscle growth, so they lost a few pounds of muscle. The high-carb group managed to get into a good calorie surplus, gaining 11 pounds of muscle while losing fat.
If the low-carb group had managed to eat more calories, perhaps they would have built more muscle. It’s hard to say because every low-carb muscle-building study runs into the same limitation: the low-carb groups can’t eat enough calories to keep up.
As for where to get your carbs, think of fruits, veggies, potatoes, sweet potatoes, all types of rice, whole grains, peas, yogurt, and a little bit of honey.
You don’t need to worry about eating extra fat while bulking. You want at least 0.3 grams of fat per pound of body weight per day, but almost everyone already eats enough, and bulking doesn’t require any extra.
So, instead of trying to eat more fats, try to eat better fats, such as nuts, seeds, avocadoes, fatty fish, extra virgin olive oil, cheese, yogurt, kefir, eggs, and avocado oil.
I’ve gained over sixty pounds of muscle, and most of it’s made of chili. When I was first bulking up, I’d cook ten servings of chili every Sunday, eat one for dinner, and save the rest for later that week, eating it once or twice every day.
Around that time, my friend Payam noticed I was getting into good shape. He wanted to get stronger while losing weight. I gave him my chili recipe and told him to split it into more servings. He lost twenty pounds that month.
Another friend, Willem, noticed Payam’s weight loss and wanted to try my “chili diet.” Not to be outdone, he too lost 20 pounds in a month.
Shortly after that, my roommate Jared ate chili every day while bulking, gaining 27 pounds in four months:
Years later, I was looking up the micronutrients in that chili recipe (which is a totally normal chili recipe I learned from my mum). It’s high in protein, rich in every single vitamin and mineral, and a great source of fibre, plugging every nutritional hole in our diets.
It might sound like I’m trying to sell you on chili, but I’m not. Our program includes a full recipe book, and my chili recipe is proudly featured, but most traditional meals are balanced and nutritious. I’m trying to sell you on the value of eating real food.
There’s a war raging on in the bodybuilding world, one side fighting for clean eating, the other for If It Fits Your Macros (IIFYM). And that’s just the bodybuilders. If you turn to the world of strength training, you’ll see a variety of other diets, ranging from keto to carnivore to outright dirty bulking.
These diets are waging serious wars against certain types of junk food, but you can do even better by more casually avoiding all the different types of junk food. You already know that donuts, soda, chips, deep-fried fast food, processed meat, and butter can be bad for you in excess. You don’t need to make demons of them, but you shouldn’t build your bulking diet around them, either.
Plenty of reasonable people recommend focusing on whole foods, and that’s a good heuristic, but it doesn’t survive much scrutiny. Yogurt is processed, but fermentation adds probiotics, making it even healthier than unprocessed milk. Whey is even more processed, but it’s rich in calcium, potassium, phosphorous, and B vitamins and has none of the saturated fat that troubles butter.
You’d think that with how common it is to be overweight, eating a bulking diet would be easy. However, most people gain weight while living sedentary lifestyles and eating too much junk food. And even then, they gain weight slowly over many years.
So we have a problem. Most people have a hard time eating in a sustained calorie surplus, and people who are naturally thin struggle most of all. That’s why we made this site. All three of us had trouble gaining weight. We wanted to help other people going through those same struggles.
We need to get into a calorie surplus in a way that’s healthy and supports muscle growth. That means we need lots of carbs, a moderate amount of protein, and plenty of healthy fats. We need a balanced mix of vitamins, minerals, soluble and insoluble fibre, probiotics, and phytonutrients. And we need to keep our intake of refined sugar and saturated fat in check.
To start, we can look at the results of an old study that measured how filling different foods were (study):
There was a 50-calorie difference for every 100 points on the satiety index. For example, someone who ate a croissant for lunch (47 satiety) would eat 150 more calories for dinner than someone who ate a boiled potato (323 satiety). Unfortunately, croissants aren’t particularly nutritious.
But look at peanuts, muesli, and brown rice. Those are exactly the sorts of foods we should eat more of. They’re rich in carbs, protein, healthy fats, vitamins, minerals, and fibre.
We can do even better. When you grind and blend food, we make it easier to chew and digest. We can eat extra-lean ground beef and chicken. We can blend fruits, veggies, nuts, and protein powder into high-calorie smoothies.
You can also eat more often. A common complaint while bulking is that the food crashes your energy levels. You can maintain steadier energy levels by eating balanced meals that are rich in fibre, but if your meals get too big, the sheer caloric load will weigh you down. Most people find it easier to sneak in snacks. Most research shows that snacking causes people to inadvertently eat more calories (study).
To make bulking easier, we want to lean into foods that are nutritious, energy-dense, and easy to digest. We have a full article on how to eat more calories and another about the best bulking foods, but here’s a list of examples to get you started:
When you think of eating a good diet, you probably wouldn’t think of bodybuilding supplements like pre-workouts, energy drinks, and protein shakes. None of the ingredients are known to be harmful, though, and they can easily fit into a balanced diet.