Effect of three types of dietary fiber on food intake in a real life setting

The diverse physical properties of dietary fiber types may differently affect satiety and food intake. The aim of this study was to determine the effect of three types of isolated dietary fiber on food intake and feelings of satiety in healthy subjects in a real life setting. In a cinema setting, six test foods were randomly offered to 121 healthy, non-restrained subjects (BMI 18–25 kg/m2). Test foods were cookies in which flour was replaced by cellulose (5%), guar gum (2.5% and 1.25%) or alginate (5% and 2.5%). The control cookie did not contain added fiber. On six test days and after a fixed preload, foods were offered in a surplus, and consumed until pleasantly satisfied. Changes in feelings of hunger, fullness, appetite and prospective food intake did not differ between the six test foods. Mean intake (±se) of the test food with 5% alginate (147.8 ± 8.5 g) was lower (p <0.001) than mean intake of the control food (177.0 ± 8.5 g). Intakes of test foods with 5% cellulose, 2.5% and 1.25% guar gum, and 2.5% alginate did not differ from control. A dose-response effect of alginate (0% > 2.5% > 5%) was found (p <0.05). Compared to control, foods with 5% cellulose, 2.5% guar gum and 5% alginate were liked less (p <0.01). Correcting the results for liking scores did not change the findings. Addition of an alginate isolate, a dietary fiber with gelling properties, to food products reduced ad libitum food intake. Effects of bulking and viscous fibers on food intake were not found.