Spotlight on Protein

I recently went to a dietetics conference that discussed the top current trends in nutrition, and one of the topics that particularly caught my attention was protein. Consumers are focusing on protein’s role in particular issues such as weight management and athletic performance. The food industry is taking notice of this trend as well. You can now buy high-protein products made from hemp, quinoa, spirulina, and even crickets (according to NPR, moms love it — we just won’t tell the kids that there are bugs in their cookies).

First of all, what exactly is protein? Protein is a macronutrient that is made up of smaller building blocks of molecules called amino acids. You need to get nine of these amino acids, called essential amino acids, through your diet; your body can make the rest. Certain foods such as meat, eggs, and dairy are complete proteins, meaning that they contain all nine essential amino acids. Vegetarian complete protein sources are less common but do exist (examples include quinoa and soy). You can also combine different plant foods such as rice and beans to get all of the amino acids that you need; this approach is called eating complementary proteins.

For healthy adults of normal weight, a standard recommendation is to consume 0.8-1.0 grams of protein per kilogram of body weight. For someone who weighs 160 pounds, this translates to 58 to 73 grams per day. This range can change based on factors such as acute illness or physiological stress (i.e. recovering from surgery) or lifestyle. For example, recreational athletes’ needs may increase to 1.1-1.4 g/kg depending on how much they exercise, whereas endurance and power athletes’ needs may go as high as 2 g/kg.

If you have a ½ cup of oatmeal for breakfast (5 grams of protein), a sandwich with 2 slices of whole wheat bread (8 grams) and 3 oz of sliced deli turkey for lunch (15 grams), and a 3 oz grilled chicken breast for dinner (26 grams), that’s 52 grams; you’ve likely already come close to getting enough protein for the day. Factor in snacks and extras (nuts on your oatmeal, cheese on your sandwich, a mid-afternoon yogurt), and there’s a good chance that you’ll meet your needs without even trying.

Eating protein throughout the day can help to stabilize blood sugar levels. Since most protein-rich foods have little to no carbohydrate, they don’t cause the body to produce lots of insulin. This can help to modulate the spike and crash that can come with eating high-carbohydrate foods on their own.

Protein can also help you to feel more full. Researchers haven’t reached a consensus on exactly why this is, but its role in blood sugar management may be involved. Other hypotheses have to do with the way that protein is broken down in the body and how this process impacts satiety hormones.

Protein, like carbohydrates, has 4 calories per gram (fat has 9 calories per gram). However, the body uses up to 30% of the calories in protein to digest it, versus 10% in fat and 3% in carbohydrate. This means that high-protein diets can be beneficial for weight loss. Of course, if you eat more calories than you expend, your body will still store the excess energy as fat regardless of the nutritional makeup of your food.

The research on protein is ongoing, and the questions that come up are certainly exciting. For example, if protein requires more energy to be broken down, could high-protein diets help speed up your metabolism in the long run? How individualized are protein requirements for athletic performance and what are all the relevant factors that influence these needs? The jury is still out for many of these questions, but stay tuned; consumer trends spur research, and we may have answers in the near future.

Snack Ideas

For reference, one large hard boiled egg has about 78 calories and 6 grams of protein. To get as much or more protein in a healthy snack, you could also try:

• 6 oz nonfat greek yogurt: 18 g protein, 100 kcal
• ¼ cup almonds: 8 g protein, 207 kcal
• 1 string cheese: 8 g protein, 80 kcal
• ½ cup frozen edamame: 9 g protein, 94 kcal
• ½ cup lowfat cottage cheese: 14 g protein, 100 kcal

References

Bligh, Maureen. “Nutrition Trends: 2017 Update + Implications.” CAND-BAD Mini-Conference, 28 January 2017, University of California: Berkeley, Berkeley, CA. Conference Presentation.

Paddon-Jones, Douglas, et al. “Protein, weight management, and satiety.” The American Journal of Clinical Nutrition 87.5 (2008): 1558S-1561S.

Sutton, Elizabeth F., et al. “No evidence for metabolic adaptation in thermic effect of food by dietary protein.” Obesity 24.8 (2016): 1639-1642.

Veldhorst, M., et al. “Protein-induced satiety: effects and mechanisms of different proteins.” Physiology & Behavior 94.2 (2008): 300-307.

Westerterp-Plantenga, Margriet S., Sofie G. Lemmens, and Klaas R. Westerterp. “Dietary protein–its role in satiety, energetics, weight loss and health.” British Journal of Nutrition 108.S2 (2012): S105-S112.