Functionality of alginate based supplements for application in human appetite regulation

The present study investigated the functional properties of different alginate solutions intended as dietary supplements for enhanced satiety and limited energy intake in humans. Characteristics of the three alginates, obtained by NMR spectroscopy, showed differences in their mannuronic:guluronic (M:G) acids ratio. By correlation with their rheological behaviour it was found that alginate solutions with low M:G (M:G = 0.8) exhibited stronger gel strength than did solutions with higher M:G (1.3 and 2.5). Subsequently, eight subjects participated in an acute meal test, where two alginate-based preloads with different M:G ratios (0.8 and 2.5) were administered after subjects had fasted overnight. Subjective appetite sensation was assessed over 4 h; thereafter an ad libitum meal was served. Self-perceived capacity for food intake decreased (P = 0.02), fullness increased (P = 0.05), and subsequent energy intake decreased numerically by 10% (P = 0.1) after consumption of the alginate formulation with low M:G compared with high M:G. These findings suggest that high-guluronic acid alginates are worth further investigation in relation to appetite regulation.