Researchers at the University of California, Berkeley, have published a study in the journal Cell that outlines their identification of a gene that is critical in turning carbohydrates into fat. The gene, called DNA-dependent protein kinase (DNA-PK), is a potential key to the prevention of obesity linked to the over-consumption of high carbohydrate foods, according to the study's authors.

It was found in the study that mice in which the gene DNA-PK had been deactivated were able to eat all the carbohydrates they wanted and still have 40 per cent less body fat than the mice in which DNA-PK was functioning.

Usually, after a meal of carbohydrates such as bread or pasta the levels of blood glucose (the digested form of carbohydrates) increase. The rise in blood glucose causes the secretion of insulin which helps the body covert glucose into energy. The excess glucose, which is not burned in energy, is usually converted to fatty acids and stored as fat.

The discovery of the DNA-PK gene may help to explain why some people can eat whatever they want without putting on weight, while others seem almost predisposed to obesity. The discovery of DNA-PK fills in the missing link by uncovering the pathway by which the conversion of excess glucose to fatty acids takes place.

Professor Hei Sook Sol, an author of the study said: 'It turns out the DNA-PK is critical to a metabolic process we have been trying to understand for many years... Identifying this signalling pathway involving DNA-PK brings us one step forwards in understanding obesity resulting from a diet of high carbohydrates, and could possibly serve as a potential pharmacological target for obesity prevention.'