Eating and sleeping are as important as working out when building muscle. Not getting enough calories or sleep will cancel your muscle gains.
This page shares the complete science of how to eat. It's a master reference:
If you do just the following things correctly on a workout day, you should successfully see muscle gains:
To repeat: If, on a given day, you nail a workout but don’t eat enough calories, you risk gaining ZERO muscle mass by the next morning. (You may still gain strength.)
Here's the implication: If you suspect you’ll be unable to eat or sleep enough on a workout day, reschedule the workout to a day where think you will.
On workout days, you have to eat enough calories to build new muscle. On non-workout days, you have to eat enough calories to avoid losing existing muscle.
If you don’t reach your bodybuilding diet's daily calorie target, your body converts existing muscle and fat into energy. That means you lose the muscle you gained.
That's the annoying part of building muscle: dieting consistency.
The Rock claims to eat nearly 5,000 calories per day. Watch his bodybuilding diet:
Your personal daily calorie target is calculated from what's called your your basal metabolic rate (BMR). BMR is the amount of calories you burn just by being awake for a day; your body uses a lot of energy to perform basic functions like pumping blood and powering your brain.
This means if you eat precisely your BMR’s worth of calories in a day, and you perform no physical activity (e.g. walking, running, weightlifting) to burn calories, you should get enough calories to prevent your body from breaking down your existing muscle.
However, since most of us aren’t sedentary, plus we’re regularly going to the gym, which itself burns calories, we must eat calories beyond our BMR to avoid being in a calorie deficit by the time we go to sleep.
Use the calculator below to estimate your daily target. The numbers outputted are how many calories you should eat on your workout and non-workout days.
Again, workout days require extra calories to make up for what you burn while exercising.
For the weight field, select what your scale says upon waking up (before eating). For the walking and non-weightlifting exercise fields (e.g. running, biking, swimming), enter how many hours of exercise you perform on average each week.
In the next section, we develop a bodybuilding diet framework for consistently achieving your calorie targets and muscle growth.
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All of this advice is recapped for you in the cheatsheet at bottom of this page.
First, there is no special "bodybuilding diet." There's just common sense nutrition and daily calorie targets. You can follow any diet you want: ketogenic, paleo, whatever. So long as you hit your protein and calorie targets, research suggests you're fine.
To consistently reach your daily calorie target, it’s critical to develop a reliable muscle building meal plan based off what I call “core foods.” These are healthy, high-calorie foods you should stock in your kitchen to form the basis of meals:
If your day's target is 2,000 calories, and you’ve chosen to eat the majority of your calories from brown rice (200 calories per can), that’s 10 cups of brown rice to eat.
In practice, I'd vary it up a bit so you balance your nutrients. For most people, the intersection of ease, price, and taste makes brown rice, sweet potatoes, and oatmeal the go-to muscle building core foods.
Every day for as long as you want to build or maintain muscle, you must eat enough to reach your calorie target.
Decide which of the core foods you’re willing to eat. Then buy a ton of them. Don’t overlook the convenience of having these simple go-to foods on-hand. Otherwise you'll cave and eat out more than you should. When you eat out, it's tough to know how many calories you're getting. There's a lot of hidden oil and sugar.
Of course, you can also eat other foods beyond these core foods. You have a life to live, and who doesn't like dining out and making home cooked meals! That's no problem. But you’ll need to develop a rough idea of the calories in the non-core meals you eat so you know how much of your core to avoid eating that day.
Keep in mind alcohol is a common sources of sneaky calories. They add up quicker than people realize. For example, a typical 250 ml bottle of fruit juice is 120 calories, and 1 can of coke or beer is 150 calories.
Now let's walk through a calorie counting example.
If you eat a 500 calorie restaurant lunch and a 1000 calorie restaurant dinner, subtract 1,500 from your 2,000 daily target to determine how many calories you must get from core foods. 500 remaining calories is 1.5 cans of beans or lentils we must eat. Hopefully we add some spice and veggies to keep it interesting.
To keep your calculations simple, you can make some assumptions when eating out:
These numbers are low-balled by 25-35% because we can’t risk undereating. Failing to hit your calorie target will hinder or prevent muscle growth from that day’s workout. (Yes, slightly overeating on workout days means you might gain a couple pounds of fat by the end of this program. But you can burn that off when you're done gaining muscle.)
If there are certain foods or meals you regularly eat, take the time to jot down the calorie counts listed on their nutritional labels. If you’re eating a prepared meal that doesn't have a label, you can use MyFitnessPal to tally up the calorie counts for the meal’s individual food items (e.g. steak, potatoes, gravy).
You don’t have to constantly do this. The goal is just to have a rough idea of how many calories you’re getting from non-core meals so you instinctively know how many cups/cans of core foods you don't have to eat that day.
If you’re in doubt about hitting your daily calorie target, follow this:
As a reference, here’s a sample meal plan for building muscle. Note how most of the calories come from beans and oatmeal (the “core foods”):
Below is an incomplete list of healthy foods. If you care about eating well—beyond what's necessary for bodybuilding—perhaps consider these too:
The common workout advice is that you should drink 2.5-3 liters per day, but the research shows there's actually no benefit to chugging back water all day (study).
Just like you get protein from the normal foods you eat, you also get water from your food (article, overview). So even if you're required to get 2.5L daily, you wouldn't have to independently drink that entire amount.
Research hasn’t reached a consensus on exactly how much water we need, but a rule of thumb is to drink two cups at breakfast, lunch, and dinner. Two notable exceptions are if you live in a hot climate or sweat a lot, in which case you should be diligent about getting enough water to avoid dehydration.
To repeat, for the purposes of bodybuilding, I have seen no evidence that there’s a specific or high daily water intake that will benefit your gains.
You now have what you need to know to build muscle. (If you landed on this page from Google, start at Page one.)
Below is the cheatsheet for this entire handbook.
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