A part of the brain that senses and integrates the sweetness and energy content of food has been identified by researchers from the University of Sydney’s Charles Perkins Centre and the nearby Garvan Institute of Medical Research.
The results of an animal study, published in Cell Metabolism last month, found evidence of a complex neuronal network that responded to artificially sweetened food by telling the animal it hadn’t eaten enough energy. Researchers believed the results had implications for the global battle against obesity.
‘The brain recalibrates’
“After chronic exposure to a diet that contained the artificial sweetener sucralose, we saw that animals began eating a lot more,” said lead researcher, Associate Professor Greg Neely from the University of Sydney’s Faculty of Science. “Through systematic investigation of this effect, we found that inside the brain’s reward centres, sweet sensation is integrated with energy content. When sweetness versus energy is out of balance for a period of time, the brain recalibrates and increases total calories consumed.”
Claim was refuted
However, the claim was refuted by The International Sweeteners Association (ISA), which argued that there was a broad body of scientific evidence from human studies that showed low-calorie sweeteners were not associated with an increase in appetite, but were effective in reducing energy intake and body weight.
In the study, fruit flies exposed to a diet laced with artificial sweeteners for more than five days were found to consume 30% more calories than when they were then given naturally sweetened food. The study was replicated using mice, with similar results.
“The pathway we discovered is part of a conserved starvation response that actually makes nutritious food taste better when you are starving,” added Neely.