The 4 Top Rules of Eating to Gain Muscle

Knowing what to eat to gain muscle will help you make gains after your strength-training workout.
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There are many reasons gaining muscle mass may be one of your goals. Whether you want to gain strength to help you run around the park with your kids, bulk up for a fitness competition or simply maintain a healthy body and muscle mass as you age, the process for building muscle is largely the same.


Gaining muscle mass requires a combination of proper nutrition and strength training — but not all diets are equally beneficial. Fueling your muscles with the necessary macronutrients in the right amounts is one of the most important factors to achieving your muscle-building goals.

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Wondering exactly what to eat to gain muscle? Read on to learn the four basic rules of eating for muscle growth.

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1. Eat More Protein

Protein is the building block of muscle tissue and contains both essential and non-essential amino acids. Non-essential amino acids are produced by our bodies naturally, while essential amino acids must be obtained via our diets.

Amino acids and proteins help our bodies synthesize hormones that help us to build muscle, says Jim White, RD, a registered dietitian and personal trainer. Amino acids also aid energy that helps us fuel our workouts as well as regulate our sleep — which is when our muscles recover and rebuild themselves, White says.


The essential amino acid leucine is especially critical for muscle repair and growth. Immediately following a workout, our muscles develop tiny tears that allow for new muscle growth — and leucine stimulates that growth and repair.

Making sure your protein sources provide enough leucine is essential for seeing gains in muscle growth. Since animal proteins contain all nine essential amino acids, you'll get your leucine from eating meats, poultry, eggs, dairy and fish.


If you're vegan or vegetarian, it's best to combine plant proteins to get a complete amino acid profile. Plant-based sources of leucine (and protein) include:

  • Firm tofu
  • Navy beans
  • Squash and pumpkin seeds
  • Peanuts

When it comes down to how much protein you should get from your diet, everyone's needs will vary.


"Total daily protein intake should be about double the recommended daily amount (RDA), so about 1.6 grams of protein per kilogram (2.2 pounds) of body weight," says Christy Alexon, PhD, RD, an associate professor at Arizona State University and sport nutrition coach for Renaissance Periodization.


And science agrees: A July 2017 meta-analysis published in the ​British Journal of Sports Medicine​ evaluated a total of over 1,800 study participants and concluded that the ideal protein intake for building muscle is up to 1.6 grams of protein per kilogram of body weight.


So, a 150-pound person would need to eat about 109 grams of protein a day to support muscle growth. However, loading your plate with even more protein might not pay off: The study also found that eating protein beyond 1.6 grams of protein per kilogram per day didn't result in any additional gains.

For reference, a three-ounce portion (about the size of a deck of cards) of lean chicken breast contains 27 grams of protein and a three-ounce portion of salmon contains 21 grams of protein. Robert Santana, RD, registered dietitian and owner of Weights & Plates in Phoenix, Arizona, offers some of the best foods to eat for muscle gain and weight loss with protein.


  • Meat jerky or vegan jerky
  • Greek yogurt and Icelandic yogurt (skyr)
  • String cheese
  • Protein shakes
  • Protein chips
  • Protein bars
  • Salads topped with meat and low-fat dressing or mustard
  • Milk

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2. Fuel Your Workouts With Carbs

Sure, you need to eat more protein to gain muscle, but protein isn't the only macronutrient you need to get shredded. Carbs play a key role in muscle-building and maintaining endurance during workouts. That's because muscle uses glycogen, which is glucose (a carb) that's stored in the liver, as fuel for your workouts.


Carbs are important for sustaining your strength training sessions and focusing on carbs coming from whole foods is key to meeting your health and muscle nutrition needs, says Santana. Foods like sweet potatoes, whole-wheat pasta, quinoa, brown rice, beans and fruit will provide a steady stream of healthy carbohydrates along with other vitamins and minerals that the body needs to adequately recover from workouts.


"Your post-workout meal should contain carbohydrates because they stimulate insulin release and insulin promotes amino acid uptake and muscle protein synthesis," Alexon says. "The ideal carb-to-protein ratio for your post-workout meal is debated in research, but most studies recommend between a 1:1 to 4:1 carb-to-protein ratio to get the most muscle-building benefits from your post-workout meal."

If gaining body fat while building muscle is something you want to avoid, then keep your fat intake at a moderate level — about 20 percent of your daily calories. "In short, the best diet for the strength trainee is one that is higher in protein and carbohydrates and moderate in fat," Santana says.

3. Increase Your Calories

Gaining muscle is a process where the body is building additional tissue — which creates a need for additional calories each day.

According to the 2020-2025 Dietary Guidelines, adult women need roughly 1,600 to 2,400 calories per day and adult men need 2,000 to 3,000 calories per day.

If your weight is currently stable, a good place to start to increase your daily calorie intake is to add 30 grams of protein to your current daily menu. This will boost your daily caloric consumption by 120 calories. Each gram of protein contains 4 calories.

While you need more calories to gain muscle mass, you want to make sure you're adding those via whole, nutritious foods like lean meat, fish, whole grains, fruits and vegetables. Increasing your calories with fried or fast foods will greatly increase your daily intake of fat and can easily lead to gaining more fat than muscle.

4. Time Your Nutrients

So now that you know what to eat, is meal timing important too? You bet.


Since your total daily protein intake should be about double the RDA, this amount should be spread out during the day by eating small protein-rich meals every three to four hours, Alexon says. "This is going to keep a steady supply of amino acids in your bloodstream during the day and reduce the amount of muscle protein breakdown that may occur."

Alexon recommends mixing a 100-percent whey isolate protein shake before the gym for longer and more intense strength-training sessions. A whey isolate protein shake is quickly digested and provides a complete protein source with all the essential amino acids needed for muscle building.

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Planning to hit the weight room in the morning? "If you are working out first thing in the morning, drink about a third of the shake upon waking up and then sip on the remaining two-thirds between exercises during your strength workout," Alexon tells us. "Then, have a post-workout meal with carbs and protein about 20 minutes after you finish strength training."

If you're working out later in the day after you've had a few meals, you'll want to sip on about half the shake during your strength workout and drink the other half immediately after your workout.

Have a post-workout meal with carbs and protein ideally within 20 to 30 minutes after you finish strength training, but your body will be in the muscle-building more for at least the next 24 hours, Alexon says. "Building muscle occurs after training, during recovery. So to build muscle, you need to not only train well but you also need to recover well from those workouts — which is where nutrition comes into play."

In fact, muscle protein synthesis increased by an impressive 25 percent when research participants spread their protein intake throughout the day versus eating the majority of their daily protein at dinner, a January 2014 study published in ​The Journal of Nutrition​ found. Researchers suggest aiming for 30 grams of protein per meal.


What About Intermittent Fasting and Bodybuilding?

Proponents of intermitted fasting — an eating pattern in which you get all or most of your daily calories in a relatively small time window — claim that intermittent fasting and bodybuilding go together really well.

During intermittent fasting, you abstain completely from food for a predetermined period of time. The idea is to deplete your glycogen and blood glucose stores. The goal is to cause your force your body to burn fat and force your body to use the protein you eat to build muscle. And, as a result, reduce body-fat levels while building lean muscle.

But is intermittent fasting good for building muscle? Research suggests no.

In an August 2020 ​Nutrients​ review, researchers explain that intermittent fasting typically coincides with a loss in lean muscle mass. In cases when people perform regular strength training in tandem, however, athletes generally maintain their muscle.

So while intermittent fasting isn't an effective diet to build significant muscle, intermittent fasting during "cutting" periods may help bodybuilders lower their body-fat percentages and reveal their muscles.

When it comes to cutting, intermittent fasting works by putting you in a caloric deficit. When you diet down for a competition, it is crucial that you are in a calorie deficit. In other words, you need to consume fewer calories than you burn. While this is certainly possible when consuming six meals per day, it means you have to be extremely strict with your food choices and portion sizes, to make sure you don't go over your planned caloric intake.

By following an intermittent fasting plan, and eating all your food within a few hours each day, controlling your calories can sometimes easier. You can have a little more leeway with your food choices, which can make for a much more pleasant dieting experience.

Preparing and cooking numerous meals to gain muscle mass every day, and taking Tupperware containers full of food with you everywhere can get very boring very quickly, and impact on your free time. Intermittent fasting allows you to be much more flexible with your meal timings, and you may only have to eat once or twice per day, which can be a lot easier, especially if you have a very busy work, family or social life.

Whatever intermittent fasting plan choose to follow, consume adequate calories, protein, carbohydrates and fats, and have a large, protein-rich meal after training. In a January 2020 ​Open Access Journal of Sports Medicine​ study, researchers recommend that athletes avoid doing high-intensity exercise while intermittent fasting


If you have hypoglycemia or diabetes, intermittent fasting may pose health risks for you. Before you try working out fasted, try a few bouts of intermittent fasting on recovery days, and pay attention to your body's response. Proceed with caution as you practice fasting on low-intensity training days.