You already know it's muscle food, but you probably didn't realize protein is so essential to your health, from fighting diseases to helping you sleep better. Here's why you need this vital macronutrient.
Blame its reputation on shake-guzzling bodybuilders and elite athletes, or the Paleo and Atkins diet fads, but we often think of protein as a muscle-building tool. It turns out that this macronutrient, which is composed of amino acids, does much more than that.
"Protein is also essential for immunity, energy levels, and building and repairing our entire bodies," says Desiree Nielsen, a registered dietitian in Vancouver.
Truth is, almost every tissue in the body needs protein: Your hair and nails are primarily made of it, and your bones, brain, skin and liver all use the amino acids derived from protein to function. Those amino acids build enzymes and hormones, including insulin. The body also uses protein to make hemoglobin, the part of our blood that delivers oxygen to our tissues. The good news for North Americans is we typically get more than enough protein. The not-so-great news? We're not consuming it consistently.
Unlike the two other macronutrients (carbohydrates and fats), protein cannot be stored in the body, so it's important that it's evenly distributed across our meals. Nielsen notes that women typically skimp on it at breakfast and lunch, then load up at dinnertime, which sets us up to give in to those 3 p.m. carb cravings.
"Protein is what makes you feel full and satisfied, which helps regulate your appetite," she says. "It also helps balance the rate at which your blood sugar climbs, preventing spikes and crashes." So while avocado toast, kale salad and fruit smoothies are packed with nutrients, complement them with sources of protein for really healthy eating. Sprinkling three tablespoons of hemp seeds (10 grams of protein) on oatmeal, adding a three-quarter cup of plain Greek yogurt (18 grams of protein) to a smoothie or tossing grilled chicken (25 grams of protein, which is about the size of a deck of cards) into a salad, for example, are easy ways to increase your intake throughout the day. Protein powders and bars can also be convenient ways to get a boost, but read the ingredients first. "Some powders have additives or are high in sugar or, worse, artificial sweeteners," says Nielsen. "And some bars are like candy with protein sprinkled in them."
Stuart Phillips, a kinesiology professor at McMaster University in Hamilton, says adults should consume 0.72 grams of protein daily for every pound of body weight. (For a 140-pound woman, that's about 100 grams each day.) He explored the impact of protein on women's weight loss in a 2011 study, published in The Journal of Nutrition, which found that the combination of a higher protein diet and exercise leads to losing fat but retaining muscle. "Losing weight by losing muscle is largely pointless, because muscle burns calories," says Phillips.
Keep in mind that not all protein sources are tops. In 2015, the World Health Organization stated that processed red meats can cause colorectal cancer. A 2011 study from the Harvard T.H. Chan School of Public Health in Boston found that both processed and unprocessed red meats can increase your risk of Type 2 diabetes, while a study published last October in the Journal of the American Medical Association reported that consuming animal protein is linked to a higher risk of cardiovascular mortality. (Plant-based proteins carry a significantly lower risk.)
That said, there's still hope for bacon fans. "If you're a red-meat lover, enjoy it," says Nielsen. "Have it once a week, and the rest of the time, eat chicken, fish or plant-based proteins."
Compared with exercising on an empty stomach, eating a high-protein meal before a 30-minute workout is a more effective way for women to burn calories, says a 2015 study out of the University of Arkansas.
Post workout pain relief
Still feeling achy days after exercising? Protein helps build and repair muscles, so low levels can result in slower recovery from extreme physical activity.
A University of Missouri researcher found that women who eat high-protein breakfasts maintain better glucose and insulin control, which researchers think may protect them from developing diabetes.
Quinoa is super healthy, but it's not as high in protein as most of us think. Half a cup of cooked quinoa has about four grams of protein. Half a cup of cooked wheat berries (5.2 grams) is a better bet.
A 2016 study published in the American Journal of Clinical Nutrition found that increasing protein—while reducing overall calories—improved overweight adults' quality and quantity of sleep.
If you're always catching a cold, you might be low on protein. Your immune system is made up of proteins, so if you're not getting enough, you have a greater risk for infection.
Researchers from England's University of Hull found that women in early menopause who ate diets rich in soy protein and isoflavones were better protected from weakening bones and osteoporosis.
As we age, we lose muscle strength and mass, also known as sarcopenia. Folks aged 65 and older should aim to get about one to 1 1/2 grams of protein per pound of body weight per day.
How do your favourite foods stack up when it comes to protein?
- 2 tbsp smooth peanut butter = 2g
- 1 cup skim milk = 8 g
- 1/2 cup edamame = 9 g
- plain bagel = 10 g
- 3/4 cup plain yogurt = 12 g
- 150 g tofu = 12 g
- 175 g cooked lentils = 15 g
- 75 g baked salmon = 18 g
- 75 g light tuna = 22 g
- 75 g tenderloin steak = 23 g