Eat 25 to 30 grams of total fiber daily. There are two kinds of fiber: soluble and insoluble. Research shows that soluble fiber, found in oats, beans, barley and citrus, helps reduce “bad” LDL cholesterol levels. Studies suggest that insoluble fiber—found in whole-wheat breads and cereals and vegetables—also helps protect your heart. Fiber extends the time food stays in your stomach, which may help you feel full for longer on fewer calories.