Apill that switches off hunger is on the horizon after scientists discovered an ‘anti-appetite’ molecule which tells the body to stop eating.
Researchers at Imperial College discovered that people feel full when eating fruit and vegetables because fibre releases acetate into the gut.
They believe that a pill derived from acetate could be created to help people cut down on food without experiencing any cravings.
One in four adults in England is obese and that figure is set to climb to 60 per cent of men and 50 per cent of women by 2050.
Obesity and diabetes already costs the UK over £5billion every year which is likely to rise to £50 billion in the next 36 years.
Large amounts of acetate are released when plants and vegetables are digested by bacteria in the colon. The scientists tracked the molecule and found that it eventually ended up in the hypothalamus region of the brain, which controls hunger.
The new study suggests obesity has become an epidemic because we have replaced the healthy diet of the past with processed food, which does not react with gut bacteria to produce acetate. So the brain does not receive a signal telling it to stop eating.
The average diet in Europe today contains about 15 g of fibre per day. In Stone Age times it was around 100g per day.
“Unfortunately our digestive system has not yet evolved to deal with this modern diet and this mismatch contributes to the current obesity epidemic,” said Professor Gary Frost, of Imperial College.
Although scientists say their research should encourage more people to eat more fruit and vegetables, they also believe it could pave the way for new drugs to help dieters.
Prof Frost added: “Our research has shown the release of acetate is central to how fibre suppresses our appetite and this could help scientists tackle overeating.
“The major challenge is to develop an approach that will deliver the amount of acetate needed to suppress appetite but in a form that is acceptable and safe for humans.
“Developing these approaches will be difficult but it is a good challenge to have and we are looking forward to researching possible ways of using acetate to address health issues around weight gain.”
The study analysed the effects of a form of dietary fibre called inulin which comes from chicory and sugar beets and is also added to cereal bars.
Experiments on mice found those fed on a high fat diet with added inulin ate less and gained less weight than animals given a lot of fat diet with no inulin.
They also noticed that the acetate acculmulates in the hypothalamus of the brain where it triggers a series of chemical events which fire neurons and suppress hunger.
The research also showed when acetate was injected into the bloodstream, the colon or the brain it reduced the amount of food eaten by the mice.
Prof Jimmy Bell, of the Medical Research Council, Cambridge, who collaborated in the research, said: “It is exciting we have started to really understand what lies behind fibre’s natural ability to suppress our appetite and identified acetate as essential to the process.
“In the context of the growing rates of obesity in western countries, the findings of the research could inform potential methods to prevent weight gain.”
Acetate is only active for a short amount of time in the body so an ‘acetate pill’ would need to be able to mimic the chemical’s slow release into the gut.
Prof David Lomas, chair of the MRC’s population and systems medicine board, said it is becoming increasingly clear the interaction between the gut and the brain plays a key role in controlling how much food we eat.
He added: “Being able to influence this relationship, for example using acetate to suppress appetite, may in future lead to new, non surgical treatments for obesity.”