In a recent study, researchers followed more than 388,000 volunteers, ages 50 to 71, and found that men and women who consumed the most fiber were 24% to 59% less likely to die from infections, heart disease or respiratory illness than those who did not. Possible reason: Fiber may steady blood sugar, lower blood lipids and control inflammation. Recommended: 21 to 25 grams of fiber daily for women and 30 to 38 grams for men from naturally occurring plant-based sources, such as grains, legumes, vegetables and fruits. Commercially made foods that are fortified with fiber were not studied.