Combining protein, carbs, and fat at every meal slows down the absorption of food, which makes you less likely to gain weight. Here’s why: fats and proteins both lower the glycemic index of carbs so we don’t get a big fat-producing insulin surge, which leads to weight gain. Fat especially slows down the absorption of anything combined with it. That’s why one nice trick is to put a little all-natural peanut butter—and I stress only all-natural peanut butter, which lists peanuts or peanuts