Fiber and weight loss have been partners in crime since forever. Studies have shown high-fiber foods usually require more chewing, which allows more time for your brain to realize that your belly is getting full. Fiber also helps your body digest food and absorb sugar more slowly, and that helps you feel satiated. Research also shows that people who have a high-fiber diet usually weigh less, which makes sense because those foods are generally low-calorie and unprocessed. So ramp up your fiber intake by adding a piece of fruit to your breakfast, one cup of sliced veggies to your sandwich or soup at lunch, and two veggies to your dinner (like a mixed green salad and roasted asparagus).