London: A new fatbusting drug that makes the body loose 12 percent of weight in a year – faster than any other drug on the market – could soon be available to UK patients.

The one-a-day tablet called Excalia which has been developed by US scientists works by tricking the metabolism into running faster.

The number of NHS prescriptions for obesity drugs has jumped almost 600 per cent since 1999. Already available in the UK are Xenical, which blocks absorption of fat, Reductil, which makes the stomach feel full, and Acomplia, which reduces cravings and stops the body storing abdominal fat.

Britain’s National Health Service spends around £1bn a year on obesity-related illness such as diabetes and the UK the worst problem with overweight adults.

The American scientists say the pill also helps weight to come off for longer. It works on the hypothalamus in the brain to boost the body’s metabolism and uses two drugs which are already widely used, against epilepsy and smoking. It also boost levels of a hormone that stops us getting hungry.