Satiety and energy intake after single and repeated exposure to gel-forming dietary fiber: post-ingestive effects

Wanders, A.J.; Mars, M.; Borgonjen-van den Berg, K.J.; Graaf, C. de; Feskens, E.J.M.


Background: Viscous or gel-forming dietary fibers can increase satiety by a more firm texture and increased eating time. Effects of viscous or gel-forming fibers on satiety by post-ingestive mechanisms such as gastric emptying, hormonal signals, nutrient absorption or fermentation are unclear. Moreover, it is unclear whether the effects persist after repeated exposure. Objective: To investigate satiety and energy intake after single and repeated exposure to gelled fiber by post-ingestive mechanisms. Design: In a two-arm crossover design, 32 subjects (24 female subjects, 21±2 y, BMI 21.8±1.9¿kg¿m-2) consumed test foods once daily for 15 consecutive days, with 2 weeks of washout. Test foods were isocaloric (0.5¿MJ, 200¿g) with either 10¿g gel-forming pectin or 3¿g gelatin and 2¿g starch, matched for texture and eating time. Hourly satiety ratings, ad libitum energy intake and body weight were measured on days 1 (single exposure) and 15 (repeated exposure). In addition, hourly breath hydrogen, fasting glucose, insulin, leptin and short-chain fatty acids were measured. Results: Subjects rated hunger, desire to eat and prospective intake about 2% lower (P0.64). After receiving pectin, energy intake was lower (-5.6%, P=0.012) and breath hydrogen was elevated (+12.6%, P=0.008) after single exposure, but not after repeated exposure. Fasting glucose concentrations were higher both after single and repeated exposure to pectin (+2.1%, P=0.019). Body weight and concentrations of insulin, leptin and short-chain fatty acids did not change during the study. Conclusions: Gelled pectin can increase satiety and reduce energy intake by post-ingestive mechanisms. Although the effects were small, the effects on satiety were consistent over time, whereas the effects on energy intake reduction were not