The effect of the gel-forming liquid fibre on feeding behaviour in man

A novel substance called liquid fibre (LF) has been developed which gels in the stomach and dramatically delays gastric emptying. The prolonged stomach distension LF causes would be expected to reduce food intake. The present study tested whether LF affected psychological factors connected with eating behaviour and short-term food intake. Paired studies were carried out on seventeen healthy but overweight volunteers (ten male, seven female) with body mass indices of 24-34 kg/m2 who were non-restricted eaters. On one occasion (randomized) they took drinks of LF (300 ml each) at 09.05, 11.55 and 18.00 hours, and on the other they took placebo drinks. Subjective feelings were assessed by visual analogue scales. The amount of food consumed at an appetizing pre-selected meal presented at 12.15 hours was measured covertly. Food diaries were kept until 16.00 hours on the following day. The visual analogue scales indicated that LF reduced hunger and the amount of food desired, and increased fullness, all of which would be expected to cause a reduction in food intake. However, there were no differences in the amount or type of food eaten at the appetizing test-meal (6073 v. 5824 kJ, P = 0.41). Food eaten later in the day was significantly delayed by LF (7.0 v. 5.9 h, P = 0.030), and the amount tended to be reduced (4328 v. 5439 kJ, P = 0.088). The energy consumed on the following day also tended to be lower after LF (3802 v. 4737 kJ, P = 0.130). This suggests that gastric distension is a relatively unimportant influence on eating behaviour when non-restricted eaters are presented with an appetizing meal and that intestinal factors seem more important for prolonging satiety and reducing subsequent food intake.