The results from the two experiments, published in Appetite, were modelled on a 2008 study by Swithers and Davidson that reported rats fed yoghurt with a non-nutritive sweetener gained more weight than those fed yoghurt with glucose, said the Australian research team behind the study.
“The claim that non-nutritive sweeteners accelerate body weight gain by disrupting sweet-calorie associations was tested in two experiments using rats,” said the team – led by Professor Bob Boakes from the University of Sydney. “Both of the current experiments likewise compared groups fed saccharin- or glucose-sweetened yoghurt in addition to chow and water.”
But contrary to previous findings using similar study conditions in 2008 and 2013, the results of the fresh experiments found that consumption of the non-nutritive sweetener saccharin had no effect on weight, while glucose did.
“Adding saccharin had no detectable effects on body-weight regulation, whereas the effects of glucose on fat pad mass were consistent with previous studies reporting more harmful effects of sugars compared to non-nutritive sweeteners,” said Boakes.
No detectable effect
In the experiments, Boakes and his colleagues split rats into three groups that were fed normal chow and water in addition to either a yoghurt sweetened with saccharin, glucose-sweetened yoghurt or unsweetened yoghurt as a control.
“In Experiment 1, but not in Experiment 2, rats were initially exposed to both saccharin- and glucose-sweetened yoghurts to assess their relative palatability,” they revealed. “We also tested whether the provision of an energy-dense sweet biscuit would augment any effects of saccharin on food intake and weight gain, as seemingly predicted by Swithers and Davidson (2008).
The Australian researchers found no differences in body weight gain or fat pad mass between the saccharin and control group, “whereas the glucose group was the heaviest by the final five weeks and at cull had the largest fat pads.”
“Weight gain in Experiment 1 was greater in glucose rats in the latter stages, while the same pattern was observed in Experiment 2 but was not statistically significant,” Boakes concluded. “Nonetheless, in both experiments significant differences in fat pad mass were observed, with higher g/kg fat in glucose-fed animals.”
Indeed, the researchers added that “no differences were detected between the saccharin and control groups on any measure.”
Boakes and the team of researchers reiterated that neither of the current experiments found greater weight gain in the saccharin than in the glucose group.
Published online ahead of print, doi: 10.1016/j.appet.2016.05.011
“Sweetening yoghurt with glucose, but not with saccharin, promotes weight gain and increased fat pad mass in rats”
Authors: Robert A. Boakes, et al