The research, which could be the holy grail for weight-watchers, was made by a team at Pennsylvania University who found a signalling pathway in the brain which may prevent the body from knowing it has had enough food.
When this stops working, people stay hungry, crave sweets and store more fat instead of burning it, increasing the risk of heart disease, diabetes and metabolic syndrome.
For the first time, the researchers have identified the body`s signalling mechanisms that contribute to "satiety" -- the sensation of feeling full, the British media reported.
It is now hoped a greater understanding of these complex mechanisms could form the basis for anti-obesity medications. Currently, no drug exists to treat obesity outright.
Team leader Matthew Hayes said: "Identifying both the site-of-action and mechanisms that account for the body weight loss from these GLP-1 drugs puts us one step closer to developing effective treatments for obesity."
Co-researcher Harvey Grill added: "Ignoring the brain is not the right strategy, as these drugs are certainly engaging multiple, distributed centres in the brain governing energy balance regulation."
The study, published in the journal Cell Metabolism, said that many researchers have tried to determine precisely how GLP-1 and other satiating signals work. This is because, especially in obese people, the brain fails to tell them that they are full, leading them to overeat.
Hayes added: "If we can identify other chemical signals or hormones that act on the same pathways that we`ve shown here, then by combined action you have a coordinated, orchestrated symphony of weight suppression."