ATLANTA — While the authors of a rodent study recently published in Appetite claim sweet tasting foods affect weight gain, the data suggests otherwise. The Calorie Control Council took a look at the full study behind the article, “Sweet taste of saccharin induces weight gain without increasing food intake, not related to insulin-resistance in Wistar rats,” and found that the data do not support the authors’ conclusions.

Study Background

The adult male rats in this study were offered either saccharin-sweetened yogurt or plain, unsweetened yogurt 22 hours a day for five days each week for 14 weeks. The rats also had unlimited access to standard laboratory food. Each week, the research team recorded how much food and water the rats consumed and how much the rats weighed. There were no differences in the amount of yogurt, laboratory food or water consumed between groups, nor was there any difference in caloric intake.

The authors reported that rats with access to the sweetened yogurt gained more weight, particularly between weeks 8 and 12 of the study, and that this effect diminished between weeks 12 and 14. At the end of the study, the authors also determined that the levels of several hormones (insulin, leptin and PYY) involved in metabolism and growth were not different.

The authors stated, “Over the 14 weeks, there was a quadratic effect of cumulative weight gain, which varied considerably in a magnitude and timing among groups. Saccharin presented a more marked weight gain compared to Control.”

Council Response

Lack of Supporting Data to Quantify Weight Gain

It is important to note that the reported “quadratic effect of cumulative weight gain” is a description of the mathematical model that is typical of the weight gain in male rats.  Without a description of the variability in weight gain within the groups or a description of any potential differences in weight gain each week, the description of the cumulative weight gain has limited value.

No Difference Shown in Food Intake

The rats did not eat different amounts of food or yogurt and did not change the amount of water they consume. This supports numerous previous studies that show saccharin does not affect food intake.  Additionally, the lack of difference in the levels of the hormone PYY, leptin or insulin has previously been reported and continues to support the established safety of saccharin.

Contrary to Larger Body on Science in Humans

More importantly, numerous research studies in humans have shown that consumption of saccharin or other low-calorie sweeteners does not lead to an increase in calorie intake or body weight if other factors are controlled. In fact, the collective evaluation of data from more than 20 studies in humans shows that low-calorie sweeteners are associated with lower body weight2.


1          Foletto KC, Melo Batista BA, Neves AM, de Matos Feijó F, Ballard CR, Marques Ribeiro MF, Bertoluci MC. Sweet taste of saccharin induces weight gain without increasing caloric intake, not related to insulin-resistance in Wistar rats. Appetite. 2015 Nov 7. pii: S0195-6663(15)30080-5. doi: 10.1016/j.appet.2015.11.003.

2          Miller PE, Perez V. Low-calorie sweeteners and body weight and composition: a meta-analysis of randomized controlled trials and prospective cohort studies. Am J Clin Nutr. 2014 Sep;100(3):765-77. doi: 10.3945/ajcn.113.082826.