How much protein we need
The recommended daily allowance (RDA) for protein is 0.8 grams per kilogram of body weight—that's about 46 grams per day for a woman and 56 grams per day for a man. However, that number could vary wildly depending on your daily caloric intake and physical activity. "If you're strength training, your body requires more protein than the average person in order to repair muscle that's broken down during training and build new muscle tissue," says Lisa Davis, PhD, chief nutrition officer at Terra's Kitchen. "The average weight lifter may need 1 gram of protein per kilogram of body weight, whereas a professional body builder may need 1.5 grams per kilogram of body weight. These signs suggest you're not getting enough protein.
Soybeans have a high protein profile—just one cup, roasted, has a whopping 37 grams. Soy also comes in the form of soy milk, tempeh, miso, and tofu. "Firm tofu packs 10 grams of protein per half cup, and the firmer the better when it comes to amount of protein," says Dr. Davis. Soy is also rich in magnesium, a nutrient needed for energy metabolism, especially when you're pumping iron (or any weight-bearing exercise) to build muscle. It also plays a vital role in muscle growth and repair. In fact, magnesium is so key to muscle building that some research suggests taking supplements when you're doing resistance training to help increase strength further, according to Krissy Kendall, PhD, of bodybuilding.com. "Low levels can lead to fatigue, lethargy, reduced powered output, and muscle cramps," she adds. If tofu makes you cringe, it could be because you've been making it all wrong. Find out how to make it tasty.
Quinoa is unique in that it's one of very few plant-based foods that's a complete protein. "Complete proteins contain all nine essential amino acids that your body needs, but can't produce on its own," says Dr. Davis. Though meat eaters get plenty of protein through beef, chicken, fish, eggs, and dairy, vegetarians and vegans can turn to quinoa, usually considered a grain but actually a seed, to help pick up the slack. Quinoa packs in 8 grams of protein per cup and is a good source of fiber and iron to boot.
Hemp seeds are loaded with protein, and no, they won't get you stoned. Just three tablespoons of hemp seeds (also known as hemp hearts, will provide 10 grams of protein and a healthy amount of omega-3 fatty acids. Just watch your portions, because at 50 calories per tablespoon, the calories from this heart-healthy fat can add up quickly. Get your daily dose by adding hemp seeds to a smoothie, atop yogurt or oatmeal, or in a salad.
A tropical fruit with protein? Dr. Davis says this exotic fruit delivers 4.2 grams of protein per cup. The good news doesn't stop there. Since guava is packed with vitamin C (100 grams provides three times the RDA) it's also a tasty way to fend off signs of skin aging, as it boosts production of collagen, which makes skin look smooth. Foods packed with vitamin C also improve your circulation.
The next time you need to make a cheesy or creamy sauce or want to add cheesy flavor to popcorn, try nutritional yeast. "Three tablespoons of this vegan staple contains 12 grams of protein, and is a good source of B vitamins," says Dr. Davis. B vitamins are essential for muscle strength. They also aid in amino acid metabolism and protein metabolism, and help repair muscles tears even as they help prevent muscle damage.
Getting enough calcium is important when you're building muscle because you need strong bones to properly anchor your muscles. "Calcium plays a critical role in both the contraction and relaxation of your muscles," says Kendall. If you don't get enough calcium, it could lead to muscle cramps, making pumping iron not so much fun. "Greek yogurt contains almost twice the protein of regular yogurt, plus it has gut-friendly probiotics and bone-strengthening calcium," says Kendall. A 6-ounce serving of 0 percent Fage Greek yogurt has 20 percent of your daily intake of calcium and 18 grams of protein. Just watch out for the prepackaged flavored varieties, which can be chockfull of added sugar. "If plain Greek yogurt doesn't do it for you, try sweetening it with a little honey or stevia and a handful of blueberries for an added antioxidant punch," suggest Kendall. Here's 10 more yummy, healthy ideas for Greek yogurt toppings.
We know that most seafood is a good source of protein, but salmon swims to the top for other reasons. "You'll also reap the benefits of its fat-fighting, cognitive enhancing omega-3 fatty acids," Kendall says. Adequate intake of omega-3's, combined with regular exercise has been shown to reduce body fat more than just exercise alone. Just 3 ounces of salmon delivers a hefty 23 grams of protein and between 1 and 1.5 grams of omega-3's. Not sure how to prepare salmon and other fresh fish? Try these delicious recipes this week.
Lean ground beef
Each 3-ounce serving of beef gives us 23 grams of protein and is a significant source of iron, amounting to about 15 percent of our recommended daily intake. "Because iron is so critical to proteins involved in oxygen transport, low iron levels can lead to fatigue, lowered immunity, feelings of weakness, and poor performance in the gym," says Kendall. Just make sure you choose the 90/10 or leaner versions of your favorite cuts to avoid extra fat and calories. Not a meat eater? Try these iron-rich foods.
Protein powders are a tasty go-to option for post-workout recovery or as a meal replacement, but not all protein powders are equal. "I like using a substantial protein powder that doesn't only contain pure protein, but also has some fiber in it for sustained energy and fullness," says Ilana Muhlstein, RD, nutritionist for Explore Cuisine. "The healthiest protein powders should have at least 15 grams of protein per scoop (usually 42 grams) and ideally have the same, if not more, grams of fiber than sugar," she says. Consider buying a protein powder that also has vitamin D, C, iron, and calcium, vital nutrients that Muhlstein says Americans are often missing.