Diet composition affects the release of gut hormones involved in the regulation of appetite and energy intake. While some research suggests high fiber foods cause greater satiety than low fiber foods, few studies have measured gut hormone levels as a mechanism by which fiber may influence appetite. A review of the literature was conducted to better understand the effect of fiber on gut hormone concentrations in humans, which specific focus on peptide YY, glucagon-like peptide-1, cholecystokinin, and ghrelin. Considerable variation was found in study design, population, fiber type and level. Few studies reported a significant effect of fiber on gut hormone levels, and data suggest caloric load may have a more significant influence on gut hormone release. While it is possible that circulating gut hormones are not the mechanism by which fibers influence satiety, it is also possible that variability in study design prevents definitive conclusions around this relationship.