Semisolid meal enriched in oat bran decreases plasma glucose and insulin levels, but does not change gastrointestinal peptide responses or short-term appetite in healthy subjects.

BACKGROUND AND AIMS: Dietary fibre (DF) may play an important role in weight control. The amount, type and way of processing of DF modify food structure and subsequent postprandial appetitive, metabolic and hormonal effects, but current understanding about the magnitude of effects that specific types and amounts of DF exert are still poorly understood.

METHODS AND RESULTS: We investigated the effects of wheat and oat brans alone and as combination in semisolid food matrix on postprandial appetite profile and gastrointestinal (GI) hormonal responses. Twenty healthy, normal-weight subjects (5 male/15 female, aged 23.3 ± 0.85y) participated in the study. Isoenergetic and isovolumic (1250 kJ, 300 g) puddings with different insoluble and soluble DF content were tested in a randomised order: pudding with 1) no added fibre, 2) 10 g wheat bran DF, 3) 10 g oat bran DF and 4) combination including 5 g wheat bran DF + 5 g oat bran DF. Blood samples were drawn before and 15, 30, 45, 60, 90, 120 and 180 min after the test meals to determine plasma glucose, ghrelin, peptide YY (PYY) and serum insulin concentrations. Subjective profiles of appetite were assessed using visual analogue scales (VAS). Plasma glucose (P = 0.001) and serum insulin (P < 0.001) responses were the lowest after the pudding with the greatest amount of β-glucan. In contrast, postprandial ghrelin or PYY responses or appetite sensations did not differ among the meals.

CONCLUSION: Oat β-glucan decreased postprandial plasma glucose and serum insulin responses, yet had no significant effects on GI peptide responses or appetite ratings.