Background: Soluble fibre has been proposed to suppress appetite-related perceptions and it could thus contribute favourably to the regulation of energy intake and the increasing obesity problem.
Objective: To investigate the effect of an oat ingredient rich in beta-glucan on perceived satiety at different dietary fibre (DF) concentrations, energy levels and viscosity levels.
Design: A total of 29 healthy volunteers, age 19-39, mean BMI 23.2 kg/m(2) participated in this study. Measurement of subjective perceptions (satiety, fullness, hunger, desire to eat something/the sample food and thirst) was performed during a 180-min period after ingestion of the sample. There were altogether six samples: two beverages without fibre at energy levels 700 and 1,400 kJ; two beverages containing 5 or 10 g oat DF (2.5 and 5 g oat beta-glucan, respectively) at energy level 700 kJ, one beverage containing 10 g oat DF/1,400 kJ and one beverage containing 10 g enzymatically treated oat DF with low viscosity at energy level 700 kJ. Each beverage portion weighted 300 g. The order of the samples was randomised for each subject and evaluated during six separate days. The results are reported in three sets of samples: 'fibre', 'energy' and 'viscosity'.
Results: In the fibre set, the beverages containing 5 or 10 g of fibre had a larger area under curve (AUC) for perceived satiety and smaller AUC for hunger compared to the beverage without fibre, but no significant dose-response relationship was detected. Increasing the energy content from 700 to 1,400 kJ in the energy set did not affect the satiety-related perceptions. In the viscosity set, the beverage with low-viscosity beta-glucan increased satiety-related perceptions from no fibre containing beverage, but less compared to the beverage with the same amount of fibre and higher viscosity.
Conclusions: Addition of an oat ingredient rich in beta-glucan and high viscosity of beverages enhance post-meal satiety induced by beverages. The effect was, however, not related to the amount of ingested fibre or energy.
Keywords: appetite; dietary fibre; energy density; hunger.