Molecular weight of barley β-glucan does not influence satiety or energy intake in healthy male subjects

Previous studies have shown the ability of high molecular weight barley β-glucan with increased viscosity to attenuate glycemic response, gastric emptying and in vitro starch digestion. The main objective of this study was to investigate the effect of molecular weight of barley β-glucan in a semisolid meal on energy intake and subjective feelings of hunger, fullness, desire to eat and prospective food consumption in healthy male subjects. In a randomised, controlled, crossover trial, 23 healthy male subjects (BMI 24.2±2.5kg/m²) tested soups equivalent to 25g available carbohydrate containing high or low molecular weight barley β-glucan (~3g) as preload after a standard breakfast. The viscosity of soup with high molecular weight β-glucan was 350Pa s whereas the soup with low molecular weight β-glucan had a viscosity of 100Pa s. Appetite ratings before and for two hours after consumption of β-glucan soups and subsequent ad libitum energy intake at lunch were recorded and compared with a control soup with no β-glucan. There was no significant difference in food intake at the ad libitum meal or for the remainder of the day following consumption of the three test foods (p>0.05). Similarly, there were no significant differences (p>0.05) in hunger, fullness, desire to eat or prospective food consumption following β-glucan soups. The current study provides evidence that the molecular weight of barley β-glucan may not impact on perceived feelings of hunger or food intake at the current dose and viscosity.