You may gain some healthy bacteria in your gut—and some bloat, at least at first.
"Your body has digestive enzymes that handle the proteins in both meat and plants, and that doesn't change when you stop eating meat," explains Liz Applegate, PhD, director of sports nutrition at the University of California, Davis. However, she says, all the indigestible carbohydrates in plant protein sources and other plant-based foods can alter the bacterial profile in your intestines. And researchers believe the new carbs can help boost the population of healthy bacteria in the gut.