Dietary fibre: the natural appetite suppressant
Dietary fibre makes you feel full and helps you lose weight – that’s not a myth! But it’s not just good for digestion, it also causes the body to release a natural appetite suppressant. In a new study by Imperial College London, researchers have now found that the healthy fibre from fruit, vegetables and whole grains promotes the release of a gut hormone that ensures satiety.
PYY hormone satisfies hunger
The study investigated whether a high-fibre diet could increase the release of the hormone PYY (peptide YY or peptide tyrosine tyrosine) in the intestine, which is known for its satiating effect. The subjects were divided into three groups.
Two groups ate a high-fibre diet with around 47 grams of fibre per day: The first group consumed the fibre in chunky form, while the participants in the second group consumed the same amount but the food was pureed. The third group had a low-fibre diet and only consumed 12 grams of fibre per day.
The hormone was then detected in so-called chyme samples: this is a paste made of saliva and gastric secretions that is excreted in the stool. The researchers were able to show that there was a greater secretion of PYY when the diet was high in fibre. The participants in the third group, who ate a low-fibre diet, not only had lower PYY values, but also got hungry again more quickly.
Pureed fibre has the same effect
Contrary to the researchers’ hypothesis that the way the fibre is prepared could have an influence, there was no difference between the participants in the two groups with a high-fibre diet: fibre contained in pureed food was just as filling and promoted hormone release as solid food that still had to be chewed.
Even babies and older people who cannot chew or can no longer chew very well benefit from the health advantages of a high-fibre diet.
How dietary fibre works
Dietary fibre, especially fermentable fibre such as resistant starch, pectin and inulin, which are found in fruits, vegetables and whole grains, are broken down by the bacteria in the large intestine into short-chain fatty acids. These short-chain fatty acids then bind to certain receptors (FFA-2 and FFA-3) that are activated in the colon cells. This in turn stimulates the release of the hormone PYY. PYY reaches the brain via the bloodstream and reduces the feeling of hunger.
The German Nutrition Society (DGE) recommends consuming 30 g of fibre a day. Since fibre swells in the stomach, you should also drink enough to prevent digestive problems. The recommended amount of liquid of 1.5 to 2 litres per day is a good guideline.