Highlights from the symposium of the International Sweeteners Association at the 24th European Congress on Obesity in Porto
Professor Maria Hassapidou, Professor of Nutrition and Dietetics, Alexander Technological Educational Institute of Thessaloniki, Greece
Media can certainly shape perception and influence public opinion and in the case of low calorie sweeteners’ use as a means to help in weight management, mixed headlines create a lot of confusion among consumers. But is media reporting in line with scientific evidence on this topic? And if not, how can this problem be addressed?
The latter was raised as an issue during the panel discussion which followed the symposium supported by the International Sweeteners Association (ISA) at the 24th European Congress on Obesity in Porto. Obviously, there is no easy answer to the previous question or a one-step solution to the problem, but scientists agree on the need of accurate media reporting in nutrition science overall.
So, what does the evidence show about low calorie sweeteners?
Before answering to this question, it is important to address which type of studies should be considered as most reliable in order to draw conclusions. While all type of research is important in nutrition science and different studies can serve different aims, the only study design involving humans that does and can demonstrate cause and effect is a randomised controlled trial (RCT). On the other hand, observational studies, which examine the relationship between two parameters (if factor A is associated with outcome B), cannot provide evidence of cause and effect. In other words, observational studies cannot distinguish direction, i.e. if the exposure to factor A influences outcome B, or vice versa, or even if both are influenced by other factors as well.
Having the above clarification in mind, the existing evidence that come from systematic reviews and meta-analyses of RCTs and from individual high-quality RCTs up to 18 months have shown a beneficial effect on calorie reduction and improvements in body weight and associated cardiometabolic risk factors when low calorie sweeteners are used to displace calories from sugars. Unlike RCTs, some observational studies, which led to big media headlines in the past, have associated the consumption of low calorie sweeteners with increased body weight, without though being able to answer to the question if it is just that people who have body weight concerns turn to low calorie sweeteners to help them lose weight.
New findings in line with existing literature
New preliminary results of an ongoing research conducted by the University of Liverpool (UK) and presented during the session, show that frequent consumers of low calorie sweeteners do not share the same beliefs as non-consumers. For example, frequent consumers have higher body weight concerns and dietary restraint, and significantly higher beliefs that low calorie sweetened beverages are palatable and effective in controlling appetite and weight, compared to non-consumers (overall sample size=211). Therefore, consumption of diet beverages may help these consumers to align potential conflicting goals, in this case, hedonic eating and successful weight control.
But the study tried to answer another important question about whether frequent consumers use low calorie beverages as a strategy to control food intake when in a state of craving. The preliminary results show that while non-consumers consumed significantly more calories in the craving condition relative to the control, the frequent consumers of low calorie sweeteners did not, which tentatively indicate that the use of diet beverages by frequent consumers is a strategy that may help to combat sweet food cravings and to successfully reduce energy intake when in a state of craving, compared to non-consumers.
These findings add to a body of data that support that low calorie sweetened beverages are a preferred option for some people trying to reduce calorie intake and manage their sweet food cravings, also in their effort to control their weight. On the other hand, for people who don’t like sweet-tasting foods, low calorie sweetened drinks might not be a solution to cravings. Individual preferences are always an important factor in deciding which strategies can be helpful in weight management.
To come back to the first question about confusing media reporting, of course, low calorie sweetened foods and beverages cannot lead to weight loss on their own or be expected to act as a magic bullet. They have to be used in place of sugar and integrated in an overall low calorie diet as part of a behavioural weight loss programme, meaning that changes in both dietary and exercise habits are equally important. However, the evidence from well-designed human studies is clear and consistently shows a positive effect of low calorie sweeteners’ use in sugar and energy reduction and therefore in weight management.
To conclude, media headlines that are confusing or frighten people about the role of low calorie sweeteners in weight control are highly problematic as they might turn people away from using low calorie sweeteners and back to consuming sugar. As we know, nutritional guidelines from the World Health Organization (WHO) as well as other organisations around the world clearly suggest that sugars’ consumption needs to be reduced. Low calorie sweeteners can therefore be a useful tool in the context of overall sugar and energy reduction, as recommended by scientific organisations globally.
To read the ISA Press Release about the outcome of the overall ISA symposium at the 24th European Congress on Obesity please click here.