PEOPLE who sleep less are more likely to be obese, according to new research published today.

Dr Shahrad Taheri, a clinical scientist at Bristol University, discovered that people who sleep for five hours a night are often hungrier, and therefore likely to eat more than those who sleep for eight hours.

Together with colleagues in the United States, Dr Taheri examined the role of two key hormones involved in regulating appetite - ghrelin and leptin.

Ghrelin increases feelings of hunger while leptin acts to suppress appetite.

The study found that people who regularly slept for five hours a night were found to have 15% more ghrelin than those who slept for eight hours. They were also found to have 15% less leptin.

Dr Taheri, author of the study, said: "These hormonal changes increase the feelings of hunger so the body sends out strong signals telling you to eat.

"We found that people who slept for shorter durations have reduced leptin and elevated ghrelin.

"These differences are likely to increase appetite and, in societies where food is readily available, this may contribute to obesity."