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Diet Soft Drinks Could Make You Eat More

New research from the University of Sydney suggests that artificial sweeteners, often found in diet soft drinks, trigger a fasting response in the brain, which increases our craving for calories.
July 13, 2016, 12:00pm

Sugar has been getting a bad rep recently and to a certain extent, rightly so. But we can still enjoy our sugar-free, "diet" soft drinks and pop a few sweeteners in our tea without feeling too guilty, right?


To add to the growing list of things that make us eat more, according to new research from the University of Sydney, consuming artificial sweeteners could trigger a fasting response in the brain and increase craving for calories.

READ MORE: Fake Sugar Might Be Making Us Sick

The findings, which looked into the long-term effects of artificial sweeteners that provide a sweet flavour but no calorific energy (in this case, sucralose), were published yesterday in the Cell Metabolism journal. They suggested that "chronic consumption of a sweet/energy imbalanced diet triggers a conserved neuronal fasting response and increases the motivation to eat."

Basically, even if you trick your body into thinking it's getting something sweet, it knows that it won't be ingesting those delicious calories. Turns out you can't have your cake and eat it after all.


Lead researcher and functional genomics expert Greg Neely explained in a press statement: "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."

The first part of Neely and his team's research studied what happened when fruit flies were "exposed to a diet laced with artificial sweetener for prolonged periods (more than five days.)" The results found that they then went on to "consume 30 percent more calories when they were then given naturally sweetened food."

To discover whether artificial sweeteners had the same effect on mammals, the second part of the study replicated the experiment using mice. Led by Herbert Herzog, an eating disorder scientist, it found the same results—namely that "mice that consumed a sucralose-sweetened diet for seven days displayed a significant increase in food consumption, and the neuronal pathway involved was the same as in the fruit flies."

READ MORE: This Lab-Grown Sweetener Is Trying to Cure Our Sugar Addiction

Although artificial sweeteners are currently prescribed as a way to treat obesity, there are still conflicting arguments for and against the full effects that "diet" and "sugar-free" products can have on the body.

Speaking to the BBC about the new research, Ros Miller from the British Nutrition Foundation said its results are not found in the majority of similar human studies and relevance to humans is "questionable". She thinks it's too simplistic to reduce food and drink consumption to a craving for sweetness in a varied human diet. She said: "The simplicity of the diets consumed by the rodents in these types of studies is in contrast to our highly complex diet."

Miller clearly has clearly never been on a 3 PM sugar scavenge.

While the arguments in favour of the artificial sweet stuff can seem a bit fishy, maybe the best thing is to ditch the Diet Coke and just have one lump in your tea. And let's be honest, you were probably going to have that mid-afternoon biscuit anyway.