Dietary fibre added to very low calorie diet reduces hunger and alleviates constipation

To examine whether supplement of dietary fibre may improve compliance to a very low calorie diet (VLCD) a nutrition powder providing 388 kcal/day (men: 466 kcal/day) was compared with a similar version containing plant fibre 30 g/day. Twenty-two obese patients entered the study. After a baseline habitual diet, they were randomized to two weeks of treatment in a single blind design to either VLCD with or without dietary fibre. Subsequently, they were crossed over for further 2 weeks of treatment. All patients completed the study. The two groups had similar weight losses (about 10 kg/4 weeks), and dietary fibre did not improve this result. During VLCD with fibre hunger ratings were significantly lower than during VLCD without fibre (fibre effect, ANOVA; P less than 0.01). Bowel movements decreased from 1.9/day on habitual diet to 0.7/day on VLCD without fibre, but increased to 1.0/day by fibre supplement (fibre effect, P less than 0.01). No effect of fibre supplementation to VLCD was found on satiety, consistency of faeces and flatulence. The supplement of dietary fibre did not influence plasma concentrations of divalent cations as calcium, iron or magnesium, nor did it add any lowering effect on plasma glucose, cholesterol or triglyceride to that of VLCD. In conclusion, the supplement of dietary fibre to VLCD may improve compliance by reducing hunger and increasing the number of bowel movements, without impairment of absorption of divalent cations.