Many people think the more protein, the better—but is that wise? Here's the lowdown on some of the best-known high-protein diet plans.
Protein is crucial to nearly every bodily function. We need it to have energy, to feel full, to build muscle, to process nutrients, and boost immunity to send chemical signals—basically, to stay alive. And with so much new research pointing to the nutrient's power as a hunger buster and super sculptor, it's easy to think the more protein, the better. But is that wise?
When experts decry protein-heavy diets, the issue is usually not quantity but quality. "It's not protein per se that's a problem, but the 'passengers' it brings with it," explains Tom Rifai, MD, regional medical director of Metabolic Health and Weight Management for the Henry Ford Health System in Detroit. "You can't compare egg whites, fish, or beans to fatty porterhouse steak." Eating a lot of meat means getting a ton of calories and saturated fat as well as a digestive by-product called TMAO, all of which can contribute to higher risks of certain cancers, diabetes, and cardiovascular disease. Indeed, a 2014 study published in Cell Metabolism showed a hike in cancer mortality risk for people who ate more animal protein in midlife. On the flip side, a new study from the Harvard T.H. Chan School of Public Health found that adults who ate a plant-based diet and dropped one or two servings of animal-based foods—to four or fewer servings a day—cut their risk of type 2 diabetes by up to 20 percent. The takeaway: If you want to bump up your protein, grab those extra grams from plant sources or even fish (both of which offer beneficial nutrients on top of protein) rather than red meat.
Curious about how some of the more popular high-protein diets stack up? Here's the lowdown.