Does dietary fiber affect food intake and body weight?

The effect of dietary fiber on energy intake or body weight has been the subject of numerous clinical studies. Critical examination of the studies shows that many have methodological problems that limit their usefulness. Problems include the absence of a placebo treatment, confounding with time, inadequate measurement of food intake, very low doses of fiber, inappropriately short treatment and observation periods, and multiple changes in the diet. The reviewed evidence indicates that supplementation with wheat bran has no effect on energy intake or body weight; however, other types of fiber may have an effect. Four studies showed that fiber supplementation resulted in a 0.2 to 0.4 kg/week greater weight loss in the treatment than in the control subjects. One study showed a decrease of 1,071 kcal/week in a subject's spontaneous intake. None of the studies reviewed followed subjects for longer than 3 months.