Science news from the 39th International Symposium on Diabetes and Nutrition
- Substituting sugars with low/no calorie sweeteners can assist with body weight and adiposity reduction, without affecting blood glucose or other cardiometabolic risk factors, as supported by a new systematic reviews and meta-analyses of controlled clinical studies
- Replacing sugar-sweetened with low/no calorie sweetened beverages is associated with reduced adiposity and incidence of heart disease, according to substitution analyses of observational research
- Better science communication is needed to help consumers understand the role of low/no calorie sweeteners in weight management and diabetes control
New evidence on the role of low/no calorie sweeteners in weight management and diabetes was presented at the 39th International Symposium on Diabetes and Nutrition, organised in Athens, Greece, on 16-19 June 2022 by the Diabetes and Nutrition Study Group (DNSG) of the European Association for the Study of Diabetes (EASD).
With the participation of internationally renowned scientific experts, the session dedicated to low/no calorie sweeteners’ latest science aimed at presenting the outcomes of a recent systematic review and meta-analysis by the World Health Organization (WHO), a series of reviews conducted with DNSG support in order to help inform the update of the EASD Dietary Guidelines for the treatment and prevention of diabetes, as well as the gaps and need for higher standards in research and reporting of science.
New evidence consistently supports the useful role of low/no calorie sweeteners
The most recent systematic reviews and meta-analyses of randomised controlled trials (RCTs) that have examined the collective scientific literature consistently show a beneficial effect of low/no calorie sweeteners’ use in assisting with modest weight loss, especially when they are used in place of sugar.1-4 A significant reduction in sugar and energy intakes, body weight and adiposity measures has been reported in the recent WHO review study1 which is in line with the findings of the DNSG-supported systematic review and meta-analysis2 and of previously published studies.3,4 Importantly also, both the WHO review and the DNSG-supported study that were presented at the conference found no evidence of negative impact on cardiometabolic risk factors including blood glucose and insulin levels, blood lipids and blood pressure.
Evidence from observational research has generated an interesting discussion at the session due to the unresolved issue of reverse causality affecting results from this type of studies. It has been highlighted in an earlier WHO study that a positive association between low/no calorie sweeteners’ consumption and weight gain in observational studies may be the consequence of and not the cause of overweight and obesity.5 Similarly, a positive association between low/no calorie sweeteners’ intake and diabetes or cardiovascular disease might be mediated by adiposity and other confounding factors, as residual confounding cannot be ruled out.6 As emphasised at the session, another important limitation of most observational studies is that they assess self-reported sweeteners’ intakes only at baseline, where only one measure of intake is compared with the disease outcome years later, without having any information on the change in sweeteners’ consumption over the years7. Based on under-publication data presented for the first time at this conference, when new statistical methods are applied aiming to help overcome some of these limitations, such as substitution and change analyses, meta-analyses of prospective cohort studies show that the substitution of sugar-sweetened beverages with low/no calorie sweetened beverages is associated with reductions in incidence of obesity, heart disease and total mortality.
Discussing the need for higher standards in research design, analysis, interpretation, and reporting, it was recommended that selection and citation of research should fairly represent the balance and weight of different types of evidence, particularly where there are available data from RCTs with relevant exposures and populations.8 Science communication in media should also reflect the totality of the scientific evidence to help consumers understand and resolve confusion over the role of low/no calorie sweeteners in weight and diabetes management.9
What does the new evidence mean for people living with overweight, obesity or diabetes?
People are increasingly trying to limit excess sugars intake aiming to improve their overall diet quality and to manage their body weight.10 Similarly, people with diabetes need to manage their carbohydrate and sugars intake to better control their blood glucose levels. However, our innate liking for sweet tasting foods and drinks is often a barrier to sugar reduction. Products sweetened with low/no calorie sweeteners which provide zero or less sugar and fewer calories, but still taste sweet, can serve as a helpful replacement strategy for sugar-sweetened products, as evidence supports their useful role in sugar and energy (calorie) reduction. Besides, in their efforts to manage their body weight and glucose control, people living with overweight, obesity or diabetes should have a variety of unsweetened and low/no calorie sweetened products available not to feel deprived of taste or choice.