New research published in the journal Cell Metabolism reveals why.

Artificial sweeteners play mind games

The brain’s reward center senses sweetness in your food and associates it with energy. When the energy doesn’t show up, your brain stimulates your appetite.

“After chronic exposure to a diet that contained the artificial sweetener sucralose, we saw that animals began eating a lot more,” lead researcher Associate Professor Greg Neely from the University of Sydney’s Faculty of Science said in a press release. “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.”

This study was carried out using fruit flies. After being given a diet including artificial sweetener for more than five days, the flies took in 30 percent more calories than when their diets contained naturally sweetened food.

The researchers then performed the same study using mice. After seven days on a diet including sucralose, the mice were eating significantly more.

The researchers say artificial sweeteners also promote hyperactivity, insomnia, and poor sleep. In previous human studies, mild starvation and fasting had the same effects.

These studies were conducted on flies and mice, not humans. Others artificial sweetener studies have had contradictory results. More controlled studies would be needed to confirm how artificial sweeteners affect our appetites over time.

In the meantime, people all around the world are using artificial sweeteners in an effort to lose or maintain weight or eat what they believe is healthier.

Natural foods in sensible portions

Just like the great butter debate, over time we’ve come to realize that we would have been better off if we had stuck with the natural version. Not that we should be eating sugar and butter with reckless abandon. They’re better than their artificial counterparts, but too much of a good thing quickly turns bad.

Another problem is that many processed foods contain hidden ingredients. People who eat a lot of them eat a lot more sugar and artificial sweeteners than they realize.

It all comes down to what most of us already know. When you have the choice, eat the foods found in nature, and in sensible portions.

How artificial sweeteners could be making you gain more weight