Acute Effect of Oatmeal on Subjective Measures of Appetite and Satiety Compared to a Ready-to-Eat Breakfast Cereal: A Randomized Crossover Trial

Objective: The physicochemical properties of soluble oat fiber (beta-glucan) affect viscosity-dependent mechanisms that influence satiety. The objective of this study was to compare the satiety impact of oatmeal with the most widely sold ready-to-eat breakfast cereal (RTEC) when either was consumed as a breakfast meal. Methods: Forty-eight healthy individuals >= 18 years of age were enrolled in a randomized crossover trial. Following an overnight fast, subjects consumed either oatmeal or RTEC in random order at least a week apart. The breakfasts were isocaloric and contained 363 kcal (250 kcal cereal, 113 kcal milk). Visual analogue scales measuring appetite and satiety were completed before breakfast and throughout the morning. The content and physicochemical properties of oat beta-glucan were determined. Appetite and satiety responses were analyzed by area under the curve (AUC). Physicochemical properties were analyzed using t tests. Results: Oatmeal, higher in fiber and protein but lower in sugar than the RTEC, resulted in greater increase in fullness (AUC: p = 0.005 [120 minute: p = 0.0408, 180 minute: p = 0.0061, 240 minute: p = 0.0102]) and greater reduction in hunger (AUC: p = 0.0009 [120 minute: p = 0.0197, 180 minute: p = 0.0003, 240 minute: p = 0.0036]), desire to eat (AUC: p = 0.0002 [120 minute: p = 0.0168, 180 minute: p < 0.0001, 240 minute: p = 0.0022]), and prospective intake (AUC: p = 0.0012 [120 minute: p = 0.0058, 180 minute: p = 0.006, 240 minute: p = 0.0047]) compared to the RTEC. Oatmeal had higher beta-glucan content, higher molecular weight (p < 0.0001), higher viscosity (p = 0.025), and larger hydration spheres (p = 0.0012) than the RTEC. Conclusion: Oatmeal improves appetite control and increases satiety. The effects may be attributed to the viscosity and hydration properties of its beta-glucan content.