Appetite and Energy Intake Review
For your information, the article “A review of the characteristics of dietary fibers relevant to appetite and energy intake outcomes in human intervention trials” was published in the September issue of the American Journal of Clinical Nutrition. The authors summarize research to potentially elucidate properties of dietary fibers that affect appetite and energy intake. The authors hypothesize that both physical effects and metabolites of dietary fiber fermentation can affect appetite and energy intake but note that dietary fibers differ in these properties. Poutanen, et al., identified 49 published articles that included 90 comparisons of dietary fibers in 40 acute and 12 sustained research protocols. Approximately one-half to one-third of studies that evaluated the acute effects of dietary fibers differing in viscosity reported increased gastrointestinal viscosity results in a beneficial effect on appetite or energy intake. It should be noted that the types of dietary fiber evaluated in these studies varied greatly (including guar and locust bean gum, pectin, psyllium, alginate, and cereal β-glucan) and methods to evaluated viscosity differed. Comparisons of alginate with gelling properties when combined with calcium all identified beneficial effects on acute appetite ratings with a dose of 1.5-19.8 grams. Fourteen studies reporting the fermentation of inulin, oligofructose, and other oligosaccharides showed mixed results for appetite and energy intake measures. Lastly, comparisons of dietary fibers varying in molecular weight were reported in 15 publications. The authors report that most studies report dietary fibers with higher molecular weight have beneficial effects on appetite but note that higher molecular weight as a property itself did not consistently reduce appetite. The authors note that the results of this review show no clear relationship among the properties of dietary fiber evaluated and the effect on appetite and energy intake. The authors propose guidelines for the use and reporting of complex materials, such as botanical supplements, should be considered for research conducted on dietary fibers to develop mechanistic knowledge and predictability of the effects of specific dietary fibers.