Artificial sweeteners can make you feel more hungry, despite their calorie-free or low-calorie content, research finds.
They have an appetite-stimulating effect on the brain, causing people to eat more and actually increasing the risk of putting on weight.
Artificial sweeteners are food additives and chemical substances that replace sugar to keep foods and drinks sweet but reduce their energy content.
Sugar substitutes such as sucralose, acesulfame potassium (acesulfame K), aspartame, neotame, and saccharin are used in many foods and drinks for losing weight and combating obesity and diabetes.
A study looked at the artificial sweeteners’ effects in changing taste perceptions and brain regulation of appetite.
They found a mechanism in the brain that tells the brain how sweet the food is and how many calories it has.
Dr Greg Neely, the study’s lead researcher, said:
“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.”
In this the study, fruit flies were given a diet laced with artificial sweetener for 5 days.
The study found that these animals were consuming 30 percent more calories compared to the time that they were exposed to naturally sweetened food.
Dr Neely said:
“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 study identified a complex neuronal network sending the information to the brain that it hasn’t eaten enough and needs calories after consuming artificially sweetened food.
Dr Neely explained:
“Using this response to artificially sweetened diets, we were able to functionally map a new neuronal network that balances food’s palatability with energy content.
The pathway we discovered is part of a conserved starvation response that actually makes nutritious food taste better when you are starving.”
Professor Herbert Herzog, who has replicated the fruit flies study in mammals using sucralose-sweetened diet, confirmed similar findings.
Professor Herzog said:
“These findings further reinforce the idea that ‘sugar-free’ varieties of processed food and drink may not be as inert as we anticipated.
Artificial sweeteners can actually change how animals perceive the sweetness of their food, with a discrepancy between sweetness and energy levels prompting an increase in caloric consumption.”
Billions of people consume artificial sweeteners in their diet hoping to lose weight, but these chemicals can significantly increase food consumption.
Previous studies have reported that artificial sweeteners increases hyperactivity and reduce sleep quality in humans.
About the author
Mina Dean is a Nutritionist and Food Scientist. She holds a BSc in Human Nutrition and an MSc in Food Science.
The study was published in Cell Metabolism (Wang et al., 2016).