The role of meal viscosity and oat β-glucan characteristics in human appetite control: a randomized crossover trial

Abstract

BackgroundFoods that enhance satiety can help consumers to resist environmental cues to eat, and improve the nutritional quality of their diets. Viscosity generated by oat β-glucan, influences gastrointestinal mechanisms that mediate satiety. Differences in the source, processing treatments, and interactions with other constituents in the food matrix affect the amount, solubility, molecular weight, and structure of the β-glucan in products, which in turn influences the viscosity. This study examined the effect of two types of oatmeal and an oat-based ready-to-eat breakfast cereal (RTEC) on appetite, and assessed differences in meal viscosity and β-glucan characteristics among the cereals.MethodsForty-eight individuals were enrolled in a randomized crossover trial. Subjects consumed isocaloric breakfast meals containing instant oatmeal (IO), old-fashioned oatmeal (SO) or RTEC in random order at least a week apart. Each breakfast meal contained 218 kcal (150 kcal cereal, and 68 kcal milk) Visual analogue scales measuring appetite were completed before breakfast, and over four hours, following the meal. Starch digestion kinetics, meal viscosities, and β-glucan characteristics for each meal were determined. Appetite responses were analyzed by area under the curve. Mixed models were used to analyze response changes over time.ResultsIO increased fullness (p = 0.04), suppressed desire to eat (p = 0.01) and reduced prospective intake (p < 0.01) more than the RTEC over four hours, and consistently at the 60 minute time-point. SO reduced prospective intake (p = 0.04) more than the RTEC. Hunger scores were not significantly different except that IO reduced hunger more than the RTEC at the 60 minute time-point. IO and SO had higher β-glucan content, molecular weight, gastric viscosity, and larger hydration spheres than the RTEC, and IO had greater viscosity after oral and initial gastric digestion (initial viscosity) than the RTEC.ConclusionIO and SO improved appetite control over four hours compared to RTEC. Initial viscosity of oatmeal may be especially important for reducing appetite.

High wholegrain barleyβ-glucan lowers food intake but does not alter small intestinal macronutrient digestibility in ileorectostomised rats

“…Thus, vagal nerve stimulation from other regions of the digestive tract, such as stomach and small intestine, are more likely contributors to modulating diet intake, especially when barley b-glucan can increase digesta viscosity in the upper gut (Brockman et al 2012) and tends to slow the rate of gastric emptying (Belobrajdic et al 2015). These observations align with clinical studies which showed that oat b-glucan increased perceptions of satiety during the postprandial period Juvonen et al 2009;Lyly et al 2010;Pentikainen et al 2014;Rebello et al 2013Rebello et al , 2014 and modulated the secretion of satiety hormones in the small intestine, including cholecystokinin, ghrelin and peptide YY Vitaglione et al 2009). Therefore, b-glucan fermentation in the large bowel is unlikely to contribute to reduced energy intake and body weight.…”

Gastrointestinal microbiome modulator improves glucose tolerance in overweight and obese subjects: A randomized controlled pilot trial

“…There is growing evidence to suggest that oat β-glucan increases satiety (Beck, et al 2009; Geliebter, et al 2015; Geliebter, et al 2014; Juvonen, et al 2009; Lyly, et al 2010; Pentikainen, et al 2014; Rebello, et al 2014; Rebello, et al 2013) and reduces post-prandial glycemia (Tosh 2013). The most likely mechanism is the viscosity generated in the gastrointestinal tract which has physiologic responses such as delayed gastric emptying, increased stomach distension, delayed intestinal transit, and reduced absorption of nutrients.…”

“…Some of these effects are satiety signals that inhibit hunger after a meal is eaten (Blundell, et al 1996). There is substantial evidence to suggest that oat β-glucan increases satiety (Beck, et al 2009; Geliebter, et al 2015; Geliebter, et al 2014; Juvonen, et al 2009; Lyly, et al 2010; Pentikainen, et al 2014; Rebello, et al 2014; Rebello, et al 2013) and that oat products reduce the human glycemic response, compared to similar wheat foods or a glucose control (Tosh 2013). Further, certain polyphenols such as the anthocyanins found in berries exhibit an insulin-like effect to influence starch degradation and thereby the post meal blood glucose response (McDougall and Stewart 2005).…”

Does food complexity have a role in eliciting expectations of satiating capacity?

“…The oat flakes presented the highest swelling and the largest particle size (Table 2). In addition, whatever the kilning and flaking processes, they contain β-glucan, a major component of oat endosperm cell walls, which probably immobilized some water during the batter preparation and pie baking (Rebello et al, 2014), contributing a drier, harder texture. In fact TPA hardness and chewiness, and Fmax and deformability from the penetration test appeared very near in the same quadrant (Fig.…”