If you’re vegan or vegetarian, you probably feel like you’ve answered the “where do you get your protein?” question a hundred times. The answer is simple, of course—your protein comes from beans, grains, nuts, seeds and vegetables. But, convincing others that plant proteins are sufficient—and even beneficial—isn’t always so easy.
Confusion about plant proteins comes from an early misunderstanding about the difference between “complete” and “incomplete” proteins. So-called complete proteins contain a ratio of the nine essential amino acids (these are the building blocks of proteins) that are a close fit to biological needs. Plant foods tend to fall a little short on one or two of the essential amino acids. But calling them “incomplete” isn’t quite right since all plant proteins contain at least some of each essential amino acid.
The old-school belief was that you need to eat plants in certain combinations to get the right mix of amino acids in the right ratio. That theory hasn’t held up, though. Newer findings show that plant foods easily meet protein needs as long as you eat a variety of them throughout the day. When vegetarians consume an array of protein sources—grains, seeds, nuts, beans and veggies—these foods work together to provide the full complement of essential amino acids. Research shows that eating foods in specific combinations at each meal isn’t important.
People who eat an exclusively plant-food diet may have slightly higher protein requirements because plant proteins have somewhat lower digestibility. To estimate your protein needs in grams, multiply your ideal body weight by 0.4. For example, a person who (ideally) weighs 130 pounds would need 52 grams of protein.
Getting protein from plant foods is not only easy; it’s also smart. Animal proteins often come packaged with saturated fat. In contrast, protein-rich plant foods provide a variety of compounds that protect against heart disease, like omega-3 fats in hempseeds, isoflavones in soyfoods and antioxidants in whole grains. Plant protein is also associated with lower blood pressure, and it may help protect kidney function in people at high risk for kidney disease. Finally, diets high in protein from dairy foods may be linked to prostate cancer risk, which suggests that nondairy options like hemp, soy, and almond milks are a healthier choice.
As long as you are eating a variety of foods and getting enough calories, plant foods can provide all the protein you need—and at the same time they offer unique protection against chronic disease that animal foods can’t match.