What new came out of the ISA Conference in 2018
Key remarks:
- Consumers use low calorie sweetened products to control food cravings and to reduce calorie intake while dieting, which potentially explains how low calorie sweeteners can help in weight loss.
- Eating something sweet, with or without calories, does not make us want to have more sweetness in our diet. Sweetness liking is innate.
- Current evidence does not support that low calorie sweeteners have adverse effect on health via impact on gut microbiota.
With sugar reduction being on the spotlight over the last years, low calorie sweeteners have become a topic of high scientific and public health interest. So, the ISA Conference 2018 entitled “The science behind low calorie sweeteners: where evidence meets policy” aimed to examine exactly that: what current evidence and emerging research supports and how these can inform nutrition policies.
Sweetness liking is innate. Can sugar substitutes help with cravings?
It is well established that we innately like sweet taste. At the same time, many people try to reduce sugars’ intake. So, keeping sweet taste in the diet without the calories of sugar could potentially help people to better manage their cravings. This hypothesis has been examined for consumers of low calorie sweeteners in the SWITCH (EffectS of non-nutritive sWeetened beverages on appetITe during aCtive weigHt loss) study undertaken by the University of Liverpool in the UK. Dr Charlotte Hardman presented new evidence that low calorie sweetened beverages are frequently used by consumers as part of a successful strategy to control cravings and food intake and to reduce negative psychological feelings such as guilt associated with eating good-tasting foods while dieting. Additionally, results of the SWITCH study indicate that people tend to eat fewer calories from sweet and savoury snack foods and feel less guilty about their food intake and more in control of their eating when low calorie sweetened beverages were available compared to unavailable. This is a very relevant finding to dietitians and nutritionists who want to be aware of different strategies that can help people with weight management issues to follow a dietary plan which can be lower in calories but tasteful at the same time.
Furthermore, during a panel discussion session at the end of the ISA Conference, the chair of the session, Prof Peter Rogers from the University of Bristol, UK, brought in the discussion a recent study by Prof Marc Fantino, an emeritus Professor from France, which compared the effects of diet drinks and water in non-consumers of low calorie sweeteners. The trial showed that, even in non-consumers, low calorie sweetened beverages did not affect appetite or sweet food intake differently compared to water. This is the latest of a series of studies confirming that low calorie sweeteners do not increase appetite and food intake.
Looking into sweetness generally, and its relationship with body weight, an issue of public health interest, Prof Kees de Graaf, Professor of Sensory Science at Wageningen University, Netherlands, presented new data published in 2018 which do not support a relationship between sweetness liking and body weight. In fact, the study that was conducted in the Netherlands by the department of Sensory Science of Wageningen University showed that people with obesity consumed less energy from sweet-tasting foods compared to normal-weight people.
Low calorie sweeteners can help in meeting sugar intake recommendations, new UK data show
In the keynote speech, Prof Adam Drewnowski, Director of the Center for Public Health Nutrition at the University of Washington, Seattle, USA, presented earlier and new studies showing that low calorie sweeteners’ use is related to a higher overall diet quality and can help people meet nutrition recommendations to reduce excess sugar intake. This was also presented by Prof Judith Buttriss, Director General of the British Nutrition Foundation (BNF), who during her speech presented conclusions from recent data analysis of the UK National Diet and Nutrition Survey (NDNS) by Prof Carlo La Vecchia and his colleagues at the University of Milan in Italy, showing that people who consume low calorie sweeteners have higher chances of meeting the sugar intake guidelines.
What about low calorie sweeteners and the gut microbiota?
About the much-debated topic of low calorie sweeteners and gut microbiota, Prof Ian Rowland, Professor at Reading University, UK, concluded that, while frequently discussed in media, current evidence does not support that low calorie sweeteners have adverse effect on insulin sensitivity or on overall health via impact on gut microbiota. Actually, it was noted that in typical levels of human consumption of low calorie sweeteners, it would be highly unlikely that low calorie sweeteners would have a clinically meaningful effect on the microbiome. Additionally, Dr Berna Magnuson, a toxicologist from Canada with extensive research on low calorie sweeteners over many years, explained that the different metabolic routes of low calorie sweeteners including their effects on gut are taken into careful consideration during the evaluation process of the safety of sweeteners, so these aspects have been examined before by the regulatory agencies. Another point worth pointing out is what Prof Rowland as well as the chair of the session, Prof Wendy Russell, University of Aberdeen, Scotland, UK, emphasized about future human studies. Future trials need to be well-designed, using human realistic consumption levels of low calorie sweeteners, and to be carefully conducted controlling for factors known to affect the gut microbiota such as changes in the diet composition or weight loss.
What’s coming next?
Many of the speakers of the ISA Conference talked about more upcoming studies that are currently being conducted in different universities around the world. These include randomised controlled trials, many of those of long-term design up to two years, that will provide additional evidence about the longer-term benefits of low calorie sweeteners. In the meantime, what evidence collectively supports is that low calorie sweeteners can help in sugar and calorie reduction, and thus aid in weight loss and maintenance of body weight loss after a diet, and that when low calorie sweeteners are used instead of sugar, they can be helpful in glucose control, as they do not cause a spike in glucose levels.
Take-home message
As a dietitian, my personal take-home message from the ISA conference is that in trying to help people to eat healthier and to make better dietary choices, we frequently forget the importance that we also have to enjoy the food we eat. By maintaining the enjoyment of sweet taste in our diet, low calorie sweeteners can help people reduce their sugar and calorie intakes and still follow an overall healthy dietary pattern, while keeping the enjoyment of eating good-tasting foods.
Please also read the ISA Conference review – Part 1: ‘What do we know about low calorie sweeteners?‘.
