Which foods do you need to eat as you strengthen your muscles? Foods rich in protein give you fuel for muscle-building workouts, but experts say you need a variety of other nutrients like carbohydrates, fiber, and healthy fats too.
Why Protein Matters
Proteins contain amino acids that repair and build muscle tissue, so you need to eat protein on a regular basis, says Laura Kruskall, PhD, director of the Dietetic Internship and Nutrition Center at the University of Nevada, Las Vegas.
Strength training stresses your muscles and causes tiny tears. To repair this damage, your body uses skeletal muscle protein, and your muscle fibers grow in strength and size, she says. Your body needs enough protein and calories to fuel this process, but our bodies don’t store excess amino acids, so we need to get them through food.
Branched-chain amino acids (BCAAs) are the nutrients in proteins that your body needs most as you work out to build muscle. They include leucine, isoleucine, and valine, Kruskall says. Good sources of BCAAs and other amino acids are animal foods like beef, pork, poultry, fish, eggs, and dairy.
“Some plant sources such as soy, peas, and quinoa also contain many essential amino acids, but they’re not of the exact same quality as animal sources,” she says. They may have a lower level of some amino acids or they might not digest as easily. It’s all about how much protein your body can absorb from the food and use for its muscle repair-and-build project.
Your muscles are made of protein. As you work out, they go through “protein turnover,” says Laura Acosta, a registered dietitian and lecturer on food science and human nutrition at the University of Florida in Gainesville.
“Muscle is not static tissue. It’s constantly broken down and built back up, so if you don’t get enough protein in your diet, your muscle can’t rebuild itself,” she says.
Go for less fatty animal proteins like chicken, lean beef cuts, or fish. Fattier proteins tend to contain saturated fats, which aren’t as healthy for your heart, she says. Fatty fish like salmon are better choices. They contain omega-3 fats, which are good for your heart.
“Plant-based protein sources like legumes are a great choice too. Beans can be the main star of your meal. Mash them up into a burger patty, or combine beans with quinoa, a grain,” she says.
Foods are complete proteins if they contain all nine essential amino acids needed for good health. Beef, poultry, fish, eggs, and milk are all complete proteins. Most plant-based foods are incomplete proteins that only contain some amino acids, Acosta says. But there are plant-based complete proteins, including quinoa, buckwheat, hempseed, blue-green algae, and soybeans. Plus you can combine incomplete proteins to make a complete one. Try mixing:
- Nuts and seeds with whole grains, like peanut butter on whole wheat toast
- Whole grains with beans, as in beans and rice, hummus and pita bread, or refried beans and tortillas
- Beans with nuts or seeds -- throw some chickpeas and sunflower seeds on a salad
“I wouldn’t worry too much about whether or not a food is an incomplete protein. Get a balance of whole, unprocessed foods and you’ll get all the amino acids you need,” she says.
Eat a Mix of Proteins
Our body can’t make its own essential amino acids, so we must get these nutrients from food, says Vijaya Surampudi, MD, assistant professor of medicine at the UCLA Division of Human Nutrition in Los Angeles. Red meat is a good source, but both chicken and fish have plenty of bioavailable amino acids, and milk, whole eggs, and cottage cheese are good proteins to help you build muscle too.
“The key to all of this is diversity,” she says. “Try to eat some protein at every meal so your body can utilize it to build muscle.”
Surampudi suggests cottage cheese with fresh fruit. Smear on some peanut or almond butter for extra protein. “Fat from nut butters helps you feel full. Beans are also a good food to add to your midday meals for extra protein, carbohydrates, and fiber, so you feel fuller longer.”
How Much Protein?
Aim for at least 25-30 grams of protein at each meal, says Joan Salge Blake, EdD, a registered dietitian and clinical associate professor of nutrition at Boston University. Sounds like a lot? It’s easy to get the protein your body needs from many foods, she says. “We’re talking a cup of yogurt -- that’s 12 grams right there.”
Here’s a quick breakdown of how much protein you get from other foods:
- 3 ounces of skinless, baked chicken: 26 grams
- 3 ounces of grilled salmon: 21 grams
- 1 cup of quinoa, 1 cup of low-fat milk, or 2 tablespoons of peanut butter: 8 grams
- 1 half-cup of black beans: 7 grams
“You want your protein intake scattered throughout the day, not ‘banked.’ Your body synthesizes protein throughout the day,” Salge Blake says. “If you do resistance exercises at your gym, you also need carbohydrates to have the energy for weightlifting. Carb-rich foods fuel your exercise, but eat protein soon afterward to synthesize your muscle tissue.”
Nuts, cheese, milk, and yogurt are good sources of protein and easy to eat on the go, she says.
Salge Blake is also a fan of cottage cheese. The protein-rich dairy food makes an easy snack or base for breakfast or lunch. One half-cup of low-fat cottage cheese packs 14 grams of protein, she says.
Other nutrients help you build muscle too:
- Carbohydrates in whole grains are converted to glycogen that’s stored in your muscle tissue and helps fuel your exercise. Yogurt and fresh fruit offer carbs and protein.
- Heart-healthy fats in foods like olive or canola oil, nuts, or avocados, salmon, or trout give your muscles energy they need to grow stronger during workouts.
If You’re Older or Overweight
Most of us aren’t ripped athletes on a rigorous weight-training regimen. If you’re older, overweight, or obese, choose foods to help you build lean muscle mass, control your weight, and keep bones strong, Kruskall says.
“Older adults should focus on foods like whole grains, fruits, and vegetables that provide carbohydrates, fiber, vitamins, and minerals,” she says. If fiber tends to make you gassy during your workouts, go for lower-fiber snacks like chicken breast or a hard-boiled egg.
All adults need protein, she says, but especially older people who are doing strength training. Maintaining muscle mass as we age is a top strategy for healthy metabolism and body weight.
Foods like milk, cheese, yogurt, and green, leafy veggies give your muscles protein, and their calcium helps you maintain bone health, which is important if you’re 50 or older. As you age, you tend to lose bone mass, and your fracture risk goes up. Weight-bearing exercises like strength training are great for building muscle and bone.
If you’re overweight or obese and want to do more strength training to shed fat, cut back on highly processed junk foods, sugar-sweetened sports beverages, and so-called protein bars, Acosta says. “If you have nothing else to eat, then a protein bar is fine. If you’re rushing to work from the gym, it’s better than nothing.”
Protein bars are processed and may contain lots of added sugars, so they’re not a great choice as you try to lose weight. “Mix up protein bars with other, healthier choices, like nuts and dried fruit. A small amount of nuts tend to satisfy your cravings so you feel full.”