Academic Diet Soda Claims Disputed by Sweeteners Industry

04 Jan 2017 --- During a commentary on current research and policy into sweetened drinks, researchers from Imperial College London have argued that sugar-free and “diet” drinks offer no more help when it comes to maintaining a healthy weight than their full-sugar counterparts.

The academics from Imperial College London and two Brazilian universities (University of Sao Paulo and Federal University of Pelotas) also suggested that they may be detrimental to the environment.

Often known as “diet” versions of soft drinks, artificially sweetened beverages (ASBs) are sweetened with artificial sweeteners, and are not taxed or regulated to the same extent as their full sugar counterparts. The researchers say that consumers often perceive ASBs as the healthier option for those who want to lose weight or reduce their sugar intake, due to their “perceived harmlessness.”

However, the academics argue that there is no solid evidence to support the claims that they are any better for health, or that they prevent obesity and obesity-related diseases such as type 2 diabetes.

Professor Christopher Millett, senior investigator from Imperial’s School of Public Health, said, “A common perception, which may be influenced by industry marketing, is that because “diet” drinks have no sugar, they must be healthier and aid weight loss when used as a substitute for full sugar versions. However we found no solid evidence to support this.”

Dr Maria Carolina Borges, first author of the study from the Federal University of Pelotas in Brazil added: “The lack of solid evidence on the health effects of ASBs and the potential influence of bias from industry-funded studies should be taken seriously when discussing whether ASBs are adequate alternatives to SSBs.”

Speaking with NutritionInsight, John Fry from Connect Consulting, disputed the claims of little evidence, saying, “The authors have either missed a number of key publications or been very selective in their assessment.”

“Their claim that there is “no solid evidence” simply does not hold up,” Fry states.

"As the recent definitive review by Rogers et al (Int J Obes (Lond). 2016 Mar;40(3):381-94 ) makes clear, “Overall, the balance of evidence indicates that use of low-energy sweeteners in place of sugar, in children and adults, leads to reduced energy intake and body weight.”

A spokesperson from the International Sweeteners Association reiterated the same point, saying "A strong body of evidence based on high-quality research affirms the beneficial role of low-calorie sweeteners’ use in foods and drinks in helping reduce overall calorie intake when used in place of sugar and as part of a balanced diet and lifestyle, thereby being a useful tool in weight management."

"In 2016, a systematic review and meta-analysis, which analysed the outcomes of 56 short-term randomised clinical trials and nine long-term studies in relation to energy intake and weight loss, concluded that the findings of the available literature are consistent in confirming that the use of low-calorie sweeteners can help reduce energy intake and thus can be helpful in weight loss."

They added, "This new publication in Plos Med by Borges et al is a commentary rather than a new clinical study or review of the literature and therefore cannot provide supporting data to the claims that there is an absence of evidence to support the role of diet drinks in preventing weight gain”.

While outlining current evidence of the health effects of consuming ASBs, Professor Millett and colleagues stated that although there was no direct evidence for a role of ASBs in weight gain, they found that there was no evidence that ASBs aid weight loss or prevent weight gain compared with the full sugar versions.

The researchers argued that despite having no or very little energy content, ASBs may trigger compensatory food intake by stimulating sweet taste receptors. This, together with the consumers’ awareness of the low-calorie content of ASBs, may result in overconsumption of other foods, thus contributing to obesity, type 2 diabetes and other obesity-related health problems.

In addition, they stated that the production of ASBs has negative consequences for the environment, with up to 300 liters of water required to produce a 0.5 L plastic bottle of carbonated soft drink.