Oat β-glucan increases postprandial cholecystokinin levels, decreases insulin response and extends subjective satiety in overweight subjects
This study recorded acute biochemical and subjective measures of satiety, followed by energy intake from a subsequent meal, after varying doses of β-glucan in extruded breakfast cereals. Molecular weight, solubility and viscosity of β-glucan products were determined. Seven male and seven female subjects (BMI 25–36 kg/m) consumed five breakfasts (different doses of β-glucan sourced from two different technological processes) and dietary intake was measured after four hours. Blood was collected to measure glucose, insulin, ghrelin and cholecystokinin, and visual analogue scales measured subjective satiety. Molecular weight, solubility and viscosity indicated products were likely to increase luminal viscosity. β-Glucan was found to decrease insulin secretion over 2 h (RMANOVA, p = 0.011) in a dose responsive manner from 2.16 to 5.68 g per serving (p = 0.007). Cholecystokinin levels increased linearly over the same range of β-glucan concentrations (p = 0.002) in women. Subjective satiety was increased at a β-glucan dose of 2.2 g (p = 0.039). Subsequent meal intake decreased by greater than 400 kJ with higher β-glucan dose (>5 g). β-Glucan improves satiety and release of cholecystokinin is likely to be part of the mechanism. Products with different sources of β-glucan provide similar benefits but each product requires individual testing.