[Dietary fiber added to a very-low caloric diet reduces hunger and alleviates constipation]

To investigate whether supplement dietary fibre improves compliance to very low calorie diets (VLCD), a nutritional powder providing 388 kcal/day was compared with a similar preparation containing 30 plant fibre per day. Twenty-two obese patients participated in the study. After three days on their habitual diet they were allocated at random according to a single blind design to VLCD either with or without dietary fibre for two weeks. Thereafter, they were crossed over to the other form of diet for two further weeks. All of the patients completed the study. Both of the groups had considerable weight losses which were similar (about 10 kg/4 weeks) and dietary fibre did not improve the result further. During the period with VLCD with fibre, hunger ratings were significantly lower than on diets with VLCD without fibre (fibre effect p less than 0.01). Bowel movements decreased from 1.9 per day on the habitual diet to 0.7 per day on VLCD without fibre but increased to 1.0 per day with the fibre supplement (fibre effect p less than 0.01). No differences were found between the effects of the two types of diet on satiety, consistency of the faeces and flatulence. The supplement of dietary fibre did not influence plasma concentrations of divalent cations such as calcium, iron or magnesium nor did it contribute to the lowering effect of VLCD on plasma glucose, cholesterol or triglyceride. It is concluded that supplementation of VLCD with dietary fibre may improve compliance by normalising hunger and increasing the number of bowel movements without impairing the absorption of divalent cations.