Addition of fiber to a meal does not consistently alter gut hormone levels in humans

Individuals with high fiber intakes tend to have a lower body weight than those who consume less fiber. Some research suggests that foods high in fiber increase satiety and may reduce energy intake. The mechanism for this is not fully understood, but may be related to changes in appetite‐related gut hormones. However, the effect of fiber on gut hormones is inconsistent in the literature. This randomized, double‐blind, crossover study aimed to examine differences in gut hormone levels following consumption of different types and combinations of dietary fiber. On 5 separate occasions, healthy men (n=10) and women (n=10) consumed either a low‐fiber control breakfast or 1 of 4 standard breakfasts containing 25 g fiber from soluble corn fiber (SCF) or resistant starch (RS), alone or in combination with pullulan (SCF+P and RS+P), a soluble fiber. All breakfasts were equal in calories and macronutrients. Blood was drawn to measure ghrelin and glucagon‐like peptide‐1 (GLP‐1) at baseline, 30, and 60 minutes after the meal. Results were analyzed as area under the curve (AUC). GLP‐1 AUC was significantly reduced for RS+P compared to control and the SCF treatments. Ghrelin values did not differ among treatments. In this study, addition of fiber to a meal did not favorably alter postprandial gut hormone levels. Supported by Tate & Lyle Health and Nutrition Sciences.