British researchers are attempting to develop a new type of diet drug based on pancreatic polypeptide, a natural hormone secreted in the gut that tells our bodies that we are full.

Pancreatic polypeptide is one of a number of chemicals released by the body when a person eats that signals the brain to stop eating, according to Professor Steve Bloom of Imperial College, London.

“Developing a treatment based on natural appetite suppression, mimicking our body's response to being full, has the potential to be safe and effective, “ said Bloom, explaining that other drugs like diet pill Acomplia (rimonabant) are less safe because they target the brain.

Bloom said people have lived for years with high levels of PP caused by benign tumors, and though chonically thin, are not even aware they have a tumor or a suppressed appetite.

“These people may have had high levels of PP for 10 or 15 years without showing side effects,” Bloom said. “In that sense, they have provided us with a natural experiment that suggests that excess levels of PP over a long period are safe. It does not appear to raise blood pressure or heart rate, or any other obvious side effects.”

When the tumors are removed, the patients gain weight.

"The trouble with PP," said fellow researcher Dr. Carolina Small, "is that it would need to be injected daily and cannot be taken as a pill. Naturally, this is not very convenient, so we need to develop an injectable form that is longer lasting and can be administered on a weekly basis to make it more practical."

Bloom and his team have been awarded a $4 million grant by the Wellcome Trust as one the three inaugural grants from their Seeding Drug Discovery initiative. If their research is successful, the researchers said it may lead to an obesity drug within five to eight years.