Scientists have discovered a genetic defect that can increase an individual's chances of becoming obese.
A team from the Monell Chemical Senses Center in Philadelphia has discovered a metabolic defect that impedes the production of fat-burning liver enzymes.
This reduces the generation of energy in cell mitochondria and thus leads to increased hunger and overeating.
Mark Friedman, the lead researcher, said the results of the study would help identify children at risk of developing obesity, independently of lifestyle factors.
Friedman also found that treatments which increase fat oxidation result in weight loss because patients consume fewer calories.
"The inherited propensity to gain weight when eating a high-fat diet appears to be due to a preexisting limit on the ability to burn fat in the liver," he said.
He added: "This defect persists during the development of obesity and is then further compounded by additional deficits in the fat oxidizing machinery.
"The present findings point to fat oxidation in the liver as a target for the development of drugs that suppress appetite and promote weight loss in obese individuals."
The study will be published in the August edition of Metabolism.