The effect of a breakfast meal comparing pure and milled oats containing 4g oat __-glucan on perceived satiety and ad libitum food intakes in normal-weight subjects. A double-blinded, randomised, placebo-controlled cross-over pilot study.

Abstract

Background: Dietary fibres are known to influence weight-loss. Oats are widely researched for their __-glucan content. Oat __-glucan is a viscous fibre associated with appetite control and can reduce blood glucose levels. It also influences gastrointestinal processes by delaying gastric emptying and thus promotes satiety. Processing differences are known to affect __-glucan viscosity of the oat grain. This study examined the effect of pure oats (OT) and milled oats (IO) on appetite control and assessed blood glucose responses. Methodology: Nine healthy participants with BMI within 18.5-24.9 kg/m2 ranges were enrolled in the pilot study. Subjects consumed three breakfast meals containing Instant oats powder (IO), Quaker oats (OT) or Special Tesco Flakes (CONTR) in a randomised manner after an 8 hour fast with a minimum 4-day washout period between visits. Each breakfast meal contained approximately 400 kcal (from milled (IO) or pure (OT) oats and cereals (CONTR). OT and IO breakfasts both contained 4g __-glucan. Visual analogue scales (VAS) were completed before breakfast, immediately after breakfast and every 15 minutes for 120 minutes to assess subjective appetite parameters. Blood glucose levels were measured via finger-prick tests over the course of 120 minutes. Mean areas under the curve (AUC) were analysed by one-way ANOVA with post-hoc Bonferroni corrections to compare subjective appetite ratings and glucose responses between breakfasts. Results: IO decreased hunger and increased fullness (p<0.05) when compared to CONTR. OT reduced hunger (p<0.05) in comparison to CONTR. Desire to eat, satisfaction and prospective food intake did not differ significantly between groups (p>0.05). There were no changes in energy intakes at the ad libitum lunch (p>0.05). Blood glucose levels were not affected by any of the meals used in the study (p>0.05). In addition, there was no significant difference between IO and OT among the study (p>0.05). Conclusion: __-glucan from oats was shown to minimize hunger and elevates fullness with no effect on blood glucose level. The difference between IO and OT was not significant which indicates that processing differences do not influence the appetite control and blood glucose responses. In addition, there was no reduction of food intake at ad libitum lunch which means that consumption of __-glucan was shown to not reduce weight. Keywords: Appetite, __-glucan, Oats, Blood glucose, ad libitum