A new vaccine has been shown to lead to decreased weight gain and less body fat in animal models and has the potential to be effective in the fight against obesity.
Scientists at the Scripps Research Institute in California found that rats which were given specific types of the active vaccine ate normally but put on less weight and had less body fat.
Dr Eric Zorrilla, assistant professor at Scripps Research, commented: "The rats who received the most effective vaccines didn't eat differently than the others, including the control models.
"That makes our findings exciting therapeutically – the vaccine slows the rate of weight gain, while still allowing for normal eating habits."
The vaccine works by preventing a hormone called ghrelin from reaching the central nervous system.
Ghrelin is known to promote weight gain and fat storage by decreasing the breakdown of stored fat and curbing energy expenditure during periods of weight loss.
It is thought to have evolved to assist survival during the feast and famine conditions endured by early humans.
Dr Kim Janda, professor of chemistry at Scripps Research, admitted that much more research is needed and said that the study doesn't claim to answer the question of obesity treatment once and for all.
"Right now it appears that active vaccination against ghrelin is one avenue that can slow weight gain and fat build-up in the body," she said.
Obesity is a growing concern and recent reports from the World Health Organisation suggest that around one billion people worldwide are either overweight or obese.
An increasing number of patients are electing to undergo obesity surgery to try and assist weight loss and reduce obesity-related health problems, such as Type 2 diabetes.