Chicory root fibres with its low energy value can reduce the caloric density of foods by replacing sugar and /or fat. Moreover, there is evidence to suggest that people eat less when chicory root fibres are added to their diet. Through fermentation by beneficial bacteria within the digestive tract, chicory root fibres induce a cascade of metabolic effects that can ultimately result in lower food intake. Scientific studies suggest that this may be caused by the short chain fatty acids produced during fermentation, which may regulate food intake through modulation of hormones involved in hunger and satiety. 

Scientific studies - A number of intervention studies in healthy, overweight and obese adults and children, has investigated the effects of chicory root fibres on energy intake for improved body weight management. Review articles indicate that dietary prebiotic supplementation may increase self-reported feelings of satiety in healthy adults and reduce post-meal glucose and insulin concentrations.  

An overview of scientific studies on this topic.