London: Scientists at Imperial College have discovered a hormone that can turn off hunger signals.

In trials patients injected with oxyntomodulin dropped more than 5lb in weight in a month. In similar trials with animals appetite was supressed to zero

The discovery paves the way for new treatment to tackle growing obesity epidemic in developed countries.

Scientists noticed that patients who had undergone surgery to reduce the size of their gut began to produce more of the hormone.

In Diabetes, the world’s top diabetes research journal, the team from Imperial College London and Hammersmith Hospitals NHS Trust reveal how patients self injectioned oxyntomodulin, a naturally occurring digestive hormone found in the small intestine, to reduce body weight and calorific intak.

The injections boost existing levels of oxyntomodulin, normally released from the small intestine as food is consumed, signalling to the brain that the body is full and has had enough to eat.

Professor Steve Bloom (pictured right), senior researcher at Imperial College London and Hammersmith Hospital, says: “The discovery that oxyntomodulin can be effective in reducing weight could be an important step in tackling the rising levels of obesity in society. Not only is it naturally occurring, so has virtually no side effects, it could be ideal for general use as it can be self administered. Despite this, we still need to conduct larger clinical trials to test its effectiveness over longer periods.”

The researchers found that over four weeks, injections of oxyntomodulin three times a day in 14 volunteers reduced their body weight by an average of 2.3kg. They also found that daily energy intake by the test group was reduced by an average of 170kcal after the first injection, to 250kcal at the end of four weeks. The average recommended intake is 2500 kcal per day for men, and 1940 for women.

The researchers also found that volunteers in the study group had lesser appetites without a reduction in food palatability.

Professor Bloom adds: “Obesity is fast becoming one of the biggest problems in society, affecting huge numbers in the western world, and with the latest figures showing 65 percent of American adults are overweight we desperately need new solutions. A reduction of up to ten percent in calorific intake would make a huge difference to the overweight, vastly improving their health. Obesity is well known as a major risk factor in all sorts of conditions, including coronary heart disease, cancer, and the development of late onset diabetes.”

The team looked at 26 volunteers over a four week period in a double blind randomised trial. The treatment group of 14 self administered oxyntomodulin 30 minutes before each meal, three times a day, over a period of four weeks. The control group of 12 volunteers administered saline at the same frequency for the same period.

The study found that leptin, a protein responsible for regulating the body’s energy expenditure was reduced in the study group. They also found reduced levels of adipose hormones, a hormone which encourages the build up of adipose tissues, a type of tissue where fat cells are stored.

Professor Bloom has set up a spin-out company, Thiakis, to commercialise this discovery, and run further trials.

The study was funded through project grants with project grants from the Wellcome Trust and the Medical Research Council.