July 28, 2008
Researchers Explore Appetite Effects Of Obesity Gene
A London-based research study found that children carrying the first gene that has been linked to obesity find it harder than others to tell when they're full.
The study assessed over 3,000 children to see whether the FTO gene impacts on the ability to burn calories or appetite.
Those with copies of the gene's risky variant were less likely to have their appetite "switched off" when they should be full, researchers said.
FTO is the first common gene to be linked to obesity in Caucasian populations.
According to previous studies, adults with two copies of the higher risk version of the gene are on average 3kg (6lb 10oz) heavier, and those with a single copy are on average 1.5kg heavier, than those without the gene.
The researchers set out to learn more about the way the gene works.
They tested whether children aged eight to 11 carrying the higher risk gene variation had an altered appetite through height, weight and waist circumference measurements. They also issued a questionnaire that asked parents about their child's eating habits.
Children with the higher risk version of the gene tended to overeat and to struggle to recognize when they were full, according to results.
The gene's effect on appetite was the same regardless of age, sex, socio-economic background and body mass index.
"It is not simply the case that people who carry the risky variant of this gene automatically become overweight, but they are more susceptible to overeating," said lead researcher Professor Jane Wardle.
"This makes them significantly more vulnerable to the modern environment which confronts all of us with large portion sizes and limitless opportunities to eat."
However, the effect of the gene in isolation was relatively small, she said.
She believes it is likely that many genes contributed to obesity and appetite, each making a small contribution, but together creating a substantial effect.
Dr. David Haslam, clinical director of the National Obesity Forum, called the research "very interesting".
"We are looking at a thousand-piece jigsaw and we have shown how the first two pieces fit together.
"It is a step in the right direction, but what we don't want to say is 'we have got the gene for obesity, therefore we can cure it' - that is not going to happen for many years to come."
The researchers, from University College London and the Institute of Psychiatry, King's College London published the study in the Journal of Clinical Endocrinology & Metabolism.
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