Why fibre really CAN reduce your appetite 

Eating lots of fibre really could help you feel more full and lose weight.

Researchers have found people who eat a range of high-fibre fruit and vegetables, or who take a fibre supplement, have less of a bile acid called isoUDCA in their body.

And people with less isoUDCA typically have lower appetites, which could help them slim down by eating less.

The study is the first to link fibre with this important type of bile acid, which could also play a role in people’s risk of cardiovascular disease.

Tim Spector, professor of genetic epidemiology at King’s College London, and co-author of the research, said: ‘This study highlights the key role that fibre plays in appetite regulation and metabolism, harnessed by specific gut microbes.

‘The gut microbiome and its chemical products such as these bile acids hold huge promise for reducing obesity without the need for invasive surgery.’

Researchers looked at four studies involving thousands of people, including two which found people who generally ate more healthily, consuming more high-fibre fruits and vegetables, had lower levels of isoUDCA.

A separate study, involving 32 older people taking a daily 20mg fibre supplement for six weeks, found they had a lower level of isoUDCA afterwards too.

Women with a lower level of isoUDCA, asked how hungry they were before breakfast over a few days, generally rated their appetite as lower in a diet study group of 327 women.

The findings suggest a lower level of isoUDCA, produced by bacteria in the gut, could reduce appetite, and that fibre supplements could reduce isoUDCA, which might be helpful for dieters.

This could mean people with a high-fibre diet, or those who take fibre supplements, might harness some of the health benefits, and the reduced appetite, experienced by very obese people after gastric bypass operations.

These people also have lower isoUDCA levels, another study in the research showed, as well as a lower level of triglycerides – fats in the blood linked to a higher risk of having a heart disease or stroke.

A lower level of isoUDCA is not only linked to lower triglycerides but may reduce the risk of non-alcoholic fatty liver disease, which is estimated to affect up to one in five people in the UK.

The study, which compared isoUDCA in twins, found the level of this bile acid is determined by the genes which run in families to some extent, but mainly is down to how we live.

It is strongly linked to our gut bacteria, which are known to play a huge role in health, and are changed by what we eat.

The best way to dramatically reduce isoUDCA is to have a gastric bypass, the study found, but fibre appears to still moderately but significantly reduce the bile acid.

The study is published in the journal Cell Reports Medicine.

WHAT SHOULD A BALANCED DIET LOOK LIKE?

Meals should be based on potatoes, bread, rice, pasta or other starchy carbohydrates, ideally wholegrain, according to the NHS

• Eat at least 5 portions of a variety of fruit and vegetables every day. All fresh, frozen, dried and canned fruit and vegetables count

• Base meals on potatoes, bread, rice, pasta or other starchy carbohydrates, ideally wholegrain

• 30 grams of fibre a day: This is the same as eating all of the following: 5 portions of fruit and vegetables, 2 whole-wheat cereal biscuits, 2 thick slices of wholemeal bread and large baked potato with the skin on

• Have some dairy or dairy alternatives (such as soya drinks) choosing lower fat and lower sugar options

• Eat some beans, pulses, fish, eggs, meat and other proteins (including 2 portions of fish every week, one of which should be oily)

• Choose unsaturated oils and spreads and consuming in small amounts

• Drink 6-8 cups/glasses of water a day

• Adults should have less than 6g of salt and 20g of saturated fat for women or 30g for men a day

Source: NHS Eatwell Guide