Artificial sweeteners may be making people overweight

A study links long-term intake of artificial sweeteners to fat accumulation, increasing the risk of obesity regardless of diet quality or caloric intake.

Over a median 17.5-year follow-up, higher consumption of total artificial sweeteners, aspartame, saccharin, and diet soda contributed to increased fat stores in the abdomen (visceral adipose tissue [VAT]), between muscles (intermuscular adipose tissue [IMAT]), and under the skin (subcutaneous adipose tissue [SAT]; p>0.05 for all). [Int J Obes 2023;doi:10.1038/s41366-023-01336-y]

Participants in the top vs bottom intake quintile of total artificial sweeteners, aspartame, and diet soda had 8.4–10.4 percent greater VAT volume, 11.6–14.8 percent greater SAT volume, and 10.6–14.8 percent greater IMAT volume. Likewise, those in the top tertile of saccharin intake had 10.3-percent higher VAT, 14-percent higher SAT, and 10-percent higher IMAT volumes compared with those in the bottom tertile.

Total artificial sweeteners, aspartame, saccharin, and diet soda were also associated with higher body mass index, body weight, waist circumference, and their increases across three timepoints (baseline, year 7, year 20) over a 25-year period.

Of note, greater risks of developing obesity were seen throughout increasing intake quintiles of total artificial sweetener (Q5 vs Q1: hazard ratio [HR], 1.68, 95 percent confidence interval [CI], 1.39–2.03), aspartame (Q5 vs Q1: HR, 1.52, 95 percent CI, 1.26–1.84), and diet soda (HR, 1.49, 95 percent CI, 1.24–1.79; p<0.001 for all).

No significant associations were observed for sucralose intake.

These findings, according to the investigators, extend evidence from previous studies by showing the associations of individual components of artificial sweeteners with anthropometric measures, their change over 25 years, and incident obesity.

“This is an especially timely study, given the World Health Organization's recent warning of the potential health risks of aspartame,” principal investigator Dr Lyn Steffen of the University of Minnesota Medical School in Minneapolis, Minnesota, US, stated. [https://www.who.int/news/item/14-07-2023-aspartame-hazard-and-risk-assessment-results-released]

The takeaway is that “habitual, long-term intakes of total and individual artificial sweetener were related to greater volumes of adipose tissue, commonly known as body fat,” added co-investigator Dr Brian Steffen of the University of Minnesota Medical School. “This was found even after accounting for other factors, including how much a person eats or the quality of one’s diet.”

In light of the present data, the recommendations from the American Diabetes Association and the American Heart Association that promote the replacement of added sugars and sugar-sweetened beverages with artificial sweeteners and diet beverages, respectively, to help curb the continuing obesity and type 2 diabetes epidemics may not be as sound as they once seemed. [Circulation 2018;138:e126-e140; Diabetes Metab Syndr 2022;16:102462; Can Med Assoc J 2017;189:e929-e939]

“Finding alternatives to artificial sweeteners in foods and beverages [is crucial], especially since these added sweeteners may have negative health consequences,” Steffen stressed.

The investigators also underscored the need for more studies to better understand the association between artificial sweetener intake and increased body fat, as well as to explore the biological processes involved in the relationship between dietary habits and metabolic health.