One small study in 19 adults found that a diet with 30% of calories from protein increased feelings of fullness and decreased daily calorie intake by 441 calories on average, compared to a diet with the same number of calories but only 15% from protein.

Another four-year study in 522 people observed that those who ate a high-fiber diet with more than 15 grams of fiber per 1,000 calories lost over five pounds (2.4 kg) more than those who ate a diet with less fiber.