A Protein Primer

Strengthen your understanding of this macronutrient

WRITTEN BY Robin Howard
PHOTOGRAPHS BY Scott Henderson & Mic Smith

Food marketers have touted high-protein diets as a silver-bullet solution for everything from weight loss to curing high blood pressure and osteoporosis. The result is a protein-obsessed population that, ironically, is already getting far more protein than it needs. While this macronutrient can help build muscle mass and is an essential part of a balanced diet, eating the correct amount and the right kind involves more than just carnivorous consumption.

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There’s so much marketing hype around eating a high-protein diet that we can now buy protein-laced cookies, coffee and water. These days, instead of low-fat or low-carb labels, marketers are cashing in on foods that boast increased protein content. With all this protein promotion, more than 70 percent of consumers say they don’t actually know what kinds of protein are healthiest or how much they should eat.

To clear up the confusion, we talked to Dr. Ryan McMonigle, a Roper St. Francis Healthcare affiliated primary care doctor. “Proteins are simply long chains of different amino acids that play a variety of roles within our bodies, including transporting cells, creating metabolic reactions and building cell structures,” says the doctor. When we eat protein, our digestive systems break it down into individual amino acids. Different cells take the kinds of amino acids they need and then assemble them into the proteins our bodies require to function. For example, tryptophan regulates appetite, sleep and mood; leucine helps wounds heal; histidine aids in the protection of nerve cells and threonine contributes to healthy skin and connective tissue.

Dr. Ryan McMonigle

Of the 20 amino acids, 11 are considered nonessential, because your body makes them and you don’t need to get them from food. The other nine are essential, meaning you have to ingest them. “Foods that contain all of the essential amino acids humans need from their diet are what we call complete proteins,” Dr. McMonigle says. “Incomplete proteins are missing one or more of those essential amino acids.”

Consider the Source
“We still benefit from incomplete proteins, but we need to make sure we’re filling in the gaps with other protein sources that contain the missing pieces,” continues the doctor. For example, legumes and whole grains are good protein sources, but individually they don’t contain enough of all nine essential amino acids. By pairing complementary foods, such as rice and beans or peanut butter and whole wheat bread, you can make a complete protein. You don’t have to eat complete proteins at every meal to stay healthy, but these combinations can keep you on the right track.

As long as you get a variety of proteins throughout the day, you’ll likely get enough of each type of amino acid.

“The healthiest protein sources are high-protein plant-based foods, fish, grass-fed meat, free-range poultry, dairy, nuts and seeds,” says Dr. McMonigle, who encourages patients to avoid processed foods. “Look for 90-percent lean beef that’s grass-fed, wild-caught fish and yogurt without any additives, stabilizers, gelatin or preservatives.” He points out that while animal proteins are generally complete, they have no fiber and can be high in calories and saturated fat. If you want to reduce your consumption of animal products, choose complete plant-based proteins such as tofu, tempeh, edamame, amaranth, quinoa, hemp seeds and chia seeds, which deliver all the essential amino acids without the saturated fat. “If you’re vegan, make sure you fill in your amino acid gaps by combining different protein sources, such as peas and rice,” he adds.

A Sense of Balance
So how much protein do we really need? According to the National Academy of Medicine’s Dietary Reference Intakes guidelines, the typical American requires 0.36 grams of protein per pound of body weight daily, about 50 grams on average (to calculate your need, simply multiply your weight by 0.36). However, the National Health and Nutrition Examination Survey reports that the average person eats as much as twice that, consuming between 70 and 102 grams per day. To help track how much protein you’re consuming, “look at the protein percentages on the dietary labels of your food,” advises the doctor. For unlabeled foods, you can estimate—a serving of protein the size of a deck of cards equals about 20 grams.

High-protein eating patterns became popular in part because the diet industry conditioned consumers to believe fat and carbohydrates are bad, or at least suspicious. High-protein diets can produce rapid weight loss results, but our fixations may be doing more harm than good. “In theory, protein makes you feel full with fewer calories; therefore, you consume less,” Dr. McMonigle says. “You want to be careful, however, not to sacrifice other energy macronutrients like healthy fats and low glycemic index carbs at the expense of too much protein. Also, consider that protein metabolism disorders and diseases like gout can be worsened by excess protein.”

A surfeit of protein over a lifetime can damage the kidneys, liver and bones, because the body struggles to process the excess. The body also can’t use or store extra protein, so unused protein calories are stored as fat, which is important to note if you’re trying to lose weight.

Mary Lee and Rob Briggs make peanut butter protein balls with their young daughters.

Hungry for More
There is also danger in eating too little protein. “Protein deficiency can interfere with your metabolism and cause fatigue, hair loss, swelling in the abdomen and legs, muscle wasting and problems with cellular repair. If you’re experiencing these symptoms, I’d recommend seeing your primary doctor,” says Dr. McMonigle.

Those who struggle to get enough protein may be tempted by pre-mixed protein shakes and powders, but Dr. McMonigle says it’s best to make your own using simple ingredients like chia seeds, hemp hearts or almond meal. “If you do buy ready-to-drink protein shakes, look closely at the ingredients labels—generally, the fewer, the better. Avoid those with excess sugar or high glycemic carbs.”

Of course, individual protein requirements vary greatly. In general, people should aim to gain 10 to 35 percent of their calories from protein. While the average American adult consumes close to double their daily protein requirement, others, such as seniors and highly active athletes, may need to bump up their intake. Not sure where you stand? A primary care doctor can help determine your specific protein needs.

Just the Essentials: The 9 essential amino acids are histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

Better Together – Try these complete protein combos: bean soup + whole wheat crackers; black beans/lentils + rice; whole wheat pasta + peas; salad with beans + seeds or nuts; whole grain bread + peanut butter; trail mix with nuts and seeds + peanuts; hummus + pita bread; green beans + sesame seeds.