Yes. Sweeteners Can Help with Maintaining a Lower Weight

As an article of faith, many people, even some who should know better, dispense advice that sweeteners are bad for metabolic health and weight management. They rely on observational evidence and theories about how they might have subtle effects to undermine health. But no direct evidence. Now, in Nature Metabolism comes a randomized controlled study to show that, in fact, sweeteners can help with maintaining a lower weight.

One Year, 348 Adults, 38 Children

In this study, everyone followed a reduced calorie diet for two months to lose at least five percent of their starting weight. All of them started with overweight or obesity. Then, for ten months, they followed a healthy ad libitum diet. Less than ten percent of their calories came from sugar. In the treatment group, foods and drinks with sweeteners replaced items that contained a lot of sugar. The control group used no products with sweeteners to replace high-sugar items.

At the end of a year, the group that used sweeteners maintained a lower average weight than the control group. The difference was 1.6 kilos or 3.5 pounds. Not a lot, but statistically significant nonetheless.

Important Reassurance

In a commentary published with this study, Sarah Schmitz and Louis Aronne remind us why this study is so meaningful:

“Sustaining weight loss is notoriously difficult, as persistent hormonal adaptations drive increased hunger and promote weight regain, reversing many of the cardiometabolic benefits achieved through weight loss.

“The SWEET trial offers reassurance that replacing sugar with a variety of sweeteners and sweetness enhancers in both foods and drinks can support weight maintenance and does not seem to harm cardiometabolic health over a year. The findings also hint at a role for the gut microbiome in determining who will benefit most, a reminder that even in the long-running sweetener debate, the answer is never one-size-fits-all.”

Indeed, what is good for one, or even for many, is seldom right for all. Especially if the subject is obesity and weight management. But those who insist sweeteners do more harm than good are preaching a gospel more than offering an objective perspective of science.

Click here for the study and here for the commentary.

Drink Can Pull Tab, photograph by Marcos André, licensed under CC BY 2.0

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October 8, 2025