Because the physiologic consequences of a high-fiber diet may depend on the type or food source of fiber, we further examined the relations between cereal, fruit, and vegetable fiber and weight change. After simultaneous adjustment for each of the 3 main sources of fiber, significant inverse associations were observed for cereal and fruit fiber, but not vegetable fiber. The dose-response relation was strongest for fruit fiber. For every 20 g/d increment in fruit fiber, weight gain was reduced by 2.51 kg (P for trend < 0.001). Because apples predominantly accounted for the fruit fiber intake (26.7%), we also calculated the mean weight gain for changes in apple consumption. Men who added a single daily apple to their diet gained 0.67 kg less weight over the 8-y period, if all other factors were held constant (P for trend < 0.0001).
Cereal fiber was inversely related to weight gain (P for trend < 0.001). For every 20 g/d increment in cereal fiber, weight gain was reduced by 0.81 kg. Similarly, changes in cold breakfast cereal consumption (servings/d) significantly predicted weight gain. Increases in intake of cereals with ≥51% whole-grain content by weight protected against weight gain (P for trend < 0.001), whereas the association with changes in intake of cereals with 25–50% whole-grain content was only marginally significant (P for trend = 0.05 for trend). In contrast, refined-grain cereals (