"The drug reduced hunger but also cravings for food and the sensation of wanting to eat and these had previously been thought to stem from different parts of the brain," said lead researcher John Blundell, professor of Psycho-Biology at the University of Leeds.
"Semaglutide" is a new drug being developed by the Danish pharmaceutical company Novo Nordisk as a treatment for diabetes. It is in the advanced stages of development but is not yet available in the market.
For the study, published in the journal Diabetes, Obesity and Metabolism, the drug was given to a few people with a body mass index (BMI) range of 30 to 45 kg/m2.
The participants were split into two groups -- half got semaglutide and the other half a placebo (dummy) substance for 12 weeks.
At the end of the 12 weeks, they were invited to a testing centre and offered lunch and evening meal and told to consume as much as they needed to feel 'pleasantly full'. What they were eating was recorded, along with food preferences and their sensations of liking and wanting food.
They then repeated the process, with participants who got semaglutide, this time getting the placebo and vice versa.
The research team found that on an average the daily energy intake, a measure of the amount of food consumed, was 24 per cent lower with semaglutide.
"The potency of the drug is probably due to the action of the GLP-1 protein receptors on broad aspects of the appetite control system including hunger, craving and rewarding aspects of food," Blundell noted.
A further feature of the study was that measured energy expenditure from metabolic processes (the Resting Metabolic Rate) remained roughly the same throughout the experiment suggesting the weight loss could not be due to metabolism becoming more active.
Consequently the fat loss produced by the drug could be attributed to better control over appetite.