Obesity has become such a large problem world wide that in Britain there are children listed on the British social services ”at risk” register because it was assumed their parents were abusing them with deliberate overfeeding. ”In one case, one of the children had been taken into care,” said Stephen O’Rahilly, a world expert on the genetics of obesity at the University of Cambridge.
But then his research team discovered the problem. The obese children had a section of DNA missing in their genetic code – a fault that produced a very strong drive to eat. ”They are very hungry children and very hard to keep healthy,” said Professor O’Rahilly.
The research, published in December, is the latest discovery in understanding better why some people are more likely than others to become overweight and obese. A food-on-tap environment had contributed to the obesity epidemic but telling people to eat less and exercise more would not solve it, Professor O’Rahilly said, when about 70 per cent of body size and shape was determined by genetic inheritance.
Professor O’Rahilly’s team found the first genetic fault linked to childhood obesity more than a decade ago and showed that giving children the protein they lacked, leptin, led to weight loss. While big genetic mistakes such as this were responsible for a small number of cases, for most overweight and obese people it was the result of a combination of many genetic variations with small effects, he said.
More than 60 of these variations have been identified and most appear to be active in the brain and to influence hunger, appetite and and satiety. ”Some of these genes will be affecting your weight by only a pound,” Professor O’Rahilly said.
Professor O’Rahilly said obesity should be regarded as a ”heritable neuro-behavioural disorder” and he hoped genetic research would lead to new treatments which, with societal and lifestyle changes, would make it as manageable as blood pressure.
