Fat-busting pill helps obese to shed two pounds a week - without changing their diets

The drug works by targeting how the body breaks down fat

After weeks of festive indulgence, seven out of 10 of us say we are determined to lose weight by going on a New Year diet.

Now trials of a new fat-busting pill suggest we could lose two pounds a week - without changing what we eat.

Start-up drugs company Zafgen have announced the results of a promising human trial of a drug called ZGN-433.

The double-blind placebo-controlled study found 24 obese women lost an average of 2lbs a week over one month - which is the maximum safe recommended amount.

The women also reported feeling fewer hunger pangs over the 26 days.

The New Scientist described the results as 'stunning' considering that the women continued to eat normally and were not given exercise advice.

It could potentially help one in four Britons who are now considered obese.

The drug, which was initially developed for the treatment of solid tumours, works by increasing the breakdown of fat.

Previous research has suggested the more overweight you become the harder it is for the body to shift it because the body becomes 'programmed' to make and store more fat.

This in turn makes the body less sensitive to the hormone insulin, which helps us to battle the bulge.

Scientists at Zafgen believe ZGN-433 blocks an enzyme, which prevents several genes from functioning properly. This means they no longer activate other genes that stop insulin from working effectively.

The U.S drugs company said the pill could potentially help individuals to lose 20 to 40 per cent of their body weight over nine months.

Dr Steven Smith at the Sanford-Burnham Medical Research Institute in Orlando said it was the first drug that appeared to be as effective as a gastric band.

He added: 'While the long-term safety and efficacy of the compound remain to be established, there is nothing in the industry drug pipeline this advanced that has shown this kind of efficacy. These early results are very encouraging.'

The data will be presented at the Keystone Symposia on Obesity in Colorado.

Zafgen now plan to launch a Phase 2a study, which will test how much of the drug should be given using a larger group of participants.