Artificial sweeteners can make you eat more, experts believe
Consuming food and drink containing artificial sweetener makes you feel hungry and eat more, research suggests.
Experts at the University of Sydney studied the effects of artificial sweeteners on the brain in regulating appetite and in altering people's taste.
Writing in the journal Cell Metabolism, they found that fruit flies fed a diet with artificial sweetener for more than five days ate 30% more calories when they were then given naturally-sweetened food.
Experts believe the sweetener prompts the brain to believe not enough calories have been taken in.
Associate professor Greg Neely, from the University of Sydney's Faculty of Science, said: "After chronic exposure to a diet that contained the artificial sweetener sucralose, we saw that animals began eating a lot more.
"When we investigated why animals were eating more even though they had enough calories, we found that chronic consumption of this artificial sweetener actually increases the sweet intensity of real nutritive sugar, and this then increases the animal's overall motivation to eat more food."
The team said this is the first study to identify how artificial sweeteners can stimulate appetite. A separate study on mice, which were fed a sucralose-sweetened diet for seven days, also found a significant increase in food consumption. The pathway identified in the brain was the same as in the fruit flies.
Prof Neely said: " The pathway we discovered is part of a conserved starvation response that actually makes nutritious food taste better when you are starving."
The researchers also found artificial sweeteners led to hyperactivity, insomnia and poorer quality sleep.
Professor Herbert Herzog, from the Garvan Institute of Medical Research in Australia, who also worked on the study, said: "These findings further reinforce the idea that 'sugar-free' varieties of processed food and drink may not be as inert as we anticipated."
In conclusion, the researchers wrote: "Chronic sweet/energy imbalance promoted hyperactivity, insomnia, glucose intolerance, enhanced sweet taste perception, and a sustained increase in food and calories consumed, effects that are reversed upon sucralose removal."