Dietary fibre and satiety

Abstract

Summary Dietary fibres have different physiological effects and provide a variety of health benefits, including satiety. They are thought to impact on satiation (the satisfaction of appetite during feeding that marks the end of eating and satiety (inhibition of hunger as a result of having eaten), because of their properties of adding bulk (satiation) and producing viscosity (satiety). Pre‐absorptive factors, such as gastric distention, and the work and time required for chewing are important for satiation. For this reason, the bulking and textural properties of fibre make it an attractive ingredient for enhancing satiation. Adding bulk to the diet with fibre will also reduce the energy density of the diet. Satiety signals are generated both pre‐ and post‐absorptively. Viscous soluble fibres may be useful because they prolong the intestinal phase of nutrient digestion and absorption. This means that there is a longer time over which the macronutrients can interact with the pre‐absorptive mechanisms of satiation and satiety, as well as prolong the time course of post‐absorptive signals. Diets low in energy and fat, such as those typically recommended for obese people, are poorly satiating. Adding fibre to low‐calorie/low‐fat foods may enhance satiety, but because weight‐loss meals are low in energy and fat, satiety is likely to be short lasting. Not all dietary fibre has an impact on satiety. We review types of dietary fibre, whole foods that contain dietary fibre, and published studies on the effect of these fibres on satiety.