Jab to stop us overeating
A daily injection which kills the appetite could stop the obesity epidemic in its tracks, scientists believe.
A naturally-occurring hormone discovered by British researchers stems the hunger pangs which make us overeat.
It is released from the gut in response to food, signalling to the brain that a meal has been eaten.
Obese people are "tricked" into eating too much because they don't produce enough of the hormone - so they still feel hungry when they should feel full-up.
The discovery could help millions who are more at risk from a host of diseases because of their weight.
Researchers from Imperial College, London, and Hammersmith Hospital found that obese people have levels of the gut hormone PYY3-36 which are lower than average.
A daily dose of this 'hunger hormone' reduces the appetite and the amount eaten by 30 per cent, they discovered.
Professor Steve Bloom said: "The discovery that obese people have lower levels of PYY3-36, an important factor limiting appetite, suggests a possible new treatment for the millions suffering from obesity."
The professor said earlier research had shown that it was possible to reduce the amount of calories eaten by lean volunteers by giving them PYY3-36. "These new findings suggest boosting PYY3-36 offers a novel approach towards treating the epidemic of obesity in our society."
The research is published today in the New England Journal of Medicine. The professor's fellow researcher Dr Rachel Batterham said: "This deficiency of PYY3-36 we observed in obese subjects could be the reason why some people become obese and others don't."
PYY3-36 is produced in the intestines. Its levels are low after fasting, but rise following a meal.
The researchers studied twelve obese and twelve lean volunteers.
After an overnight fast subjects were given either a dose of PYY3-36, or a dummy drug.
They were not told which they had been given, and were offered an unlimited buffet two hours later.
All 24 volunteers ate less on the day when they received a PYY3-36 dose compared with the 'dummy' day. Overall PYY3-36 reduced calorific intake by a third in both the lean and obese subjects. Dr Batterham added: "Obesity is a global epidemic that is getting worse. Seventeen percent of children in the UK are obese.
"At the current rates of increase, it will pass smoking as the main cause of preventable death."
Being overweight or obese increases the risk of heart disease, diabetes, stroke and other illnesses.
Eleanor Kennedy, research director of Diabetes UK, said: "Anything which helps obese people regulate their appetite could potentially reduce the number of people developing Type 2 diabetes.
"There needs to be further research into this subject."
Dr Ian Campbell, chairman of the National Obesity Forum, said lifestyle changes had to remain the top priority, whatever new drugs became available, but added: "It's encouraging that we are increasing our knowledge, and if this does lead to better drugs, it's got to be welcomed."