A study has found that so-called ‘diet’ soft drinks may cause weight gain, rather than contribute to weight loss, with the sweeteners used in them being blamed.
Scientists from Massachusetts General Hospital claim the low-calorie, low-sugar drinks are filled with chemicals that have a negative effect on a person’s metabolism. However, the British Soft Drinks Association (BSDA), has labelled these claims as “baseless”.
Aspartame, an artificial, non-saccharide sweetener, has been named as the offending culprit. The tests, which were conducted on mice, found that those who had been given aspartame in their drinks gained more weight, and suffered more metabolic issues than those who hadn’t.
Over a period of 18 weeks, the scientists analysed four groups of mice; two groups were given a normal diet, with the other two groups given a high-fat diet. In both diets, one group had plain water and one had water containing aspartame.
When the trial ended there was little difference between the weights of the two groups on a normal diet, however the mice given a high-fat diet and aspartame put on more weight than those mice on the same diet that were given just plain water.
On top of this, higher blood glucose levels and higher levels of inflammation were recorded in the mice that were given aspartame, compared to those given just plain water.
Dr Richard Hodin, senior author of the report, said: “Sugar substitutes like aspartame are designed to promote weight loss and decrease the incidence of metabolic syndrome, but a number of clinical and epidemiologic studies have suggested that these products don’t work very well and may actually make things worse.
“We found that aspartame blocks a gut enzyme called intestinal alkaline phosphatase (IAP) that we previously showed can prevent obesity, diabetes and metabolic syndrome. So, we think that aspartame might not work because, even as it is substituting for sugar, it blocks the beneficial aspects of IAP.”
BSDA Director General Gavin Partington said: “These claims are being made by a study conducted on mice and run contrary to the overwhelming body of scientific evidence.
“Decades of scientific research, including human clinical trials, show that low-calorie sweeteners, such as those in diet drinks, have been found to help consumers manage their calorie intake when part of an overall healthy diet.”
The findings were published in the journal Applied Physiology, Nutrition and Metabolism.