The science underpinning both short (episodic) and long (tonic) term appetite regulation demonstrates that foods higher in macronutrients such as fibre can, under certain experimental conditions, produce great decreases in feelings of hunger and increases in fullness, post consumption, compared to equi-caloric loads of high carbohydrate or high fat. Given that fibre increases the release of GLP-1, slows down gastric emptying, prolongs nutrient absorption and, over long-term use increases the generation of short chain fatty acids (SCFAs) which have been linked to improved satiety responding, it is plausible that it will produce strong effects on within meal processes of satiation and satiety over the short- and long-term. Fibre has also been suggested to influence carbohydrate fermentation (via generation of these SCFAs) and improve the insulin response, additionally improving satiety. Ingredients may be added to boost fibre content such as the use of polydextrose, which is a non-digestible polysaccharide usually used as a dietary fibre in foods. Polydextrose has also been shown to increase levels of SCFAs due to its slow fermentation and has been related to reductions in subsequent intake and/or reduced hunger.