A little-discussed factor that can make dieting difficult is the issue of tolerance. Our bodies get used to a certain amount of fat, a certain amount of sugar, or a certain amount of salt. The more we eat, the more that tolerance builds—and that just makes us need more of the stuff in order to “taste” it.
Now a study shows it may be possible to reverse that trend and quiet the demands of a sweet tooth. Other studies have shown that it’s possible to retrain the taste buds to desire less salt — decrease the amount of salt you eat for a while and then the same foods you found acceptable start to taste too salty.
Now, in a small study published in the American Journal of Clinical Nutrition, researchers found that the same training to reduce people’s taste for sugar might be possible. They recruited 29 people who said they regularly drank at least two sugar-sweetened beverages a day and asked them to rate the sweetness of some sweetened puddings and drinks. The scientists then asked half of the people to reduce their sugar by 40% (they could do so by eating or drinking whatever they wanted) and allowed the other half to continue with their regular diets.
After three months, the people in the study, which was funded by the Monell Chemical Senses Center and PepsiCo, went back to eating whatever they wanted to eat for a month. The scientists monitored any changes in their sugar intake by asking the people to rate lightly sweetened puddings and beverages.
The people who lowered the amount of sugar they ate during the study consistently reported that the puddings and drinks with little sugar tasted sweeter than did the group that didn’t reduce their sugar consumption, suggesting that their taste or tolerance for sugar had changed after eating less of it. The effect was stronger for the puddings than for the drinks, which the researchers say could be related to differences in the way foods and liquids are processed by the body.
The effect did not last when the people went back to eating what they wanted. The group that had lowered the amount of sugar they ate went back to eating just as much as they had at the start of the study.
Also, even during the study, the people who ate less sugar did not report any changes in how pleasurable the sweetened puddings or drinks were — pleasantness, or "reward," is one of factors that some experts say may be involved in eating preferences.
The study only involved a small number of people, and the fact that the low-sugar group went back to increasing the amount of sweet foods they ate certainly doesn’t prove that the effects of a sweet tooth can be dampened. But they hint that it may be possible, and support the need for more research into how our tolerance or “taste” for foods can be adjusted.