New research presented at this year’s European Congress on Obesity (ECO) in Venice, Italy (May 12-15), suggests that replacing sugary foods and drinks with low- or no-energy sugary products may help control weight for at least one year after rapid weight loss in adults, without increasing the risk of type 2 diabetes or cardiovascular disease.
Findings from a one-year randomized controlled trial involving overweight and obese adults and overweight children from Northern, Central and Southern Europe also found that consumption of sweeteners and sweeteners (S&SE) was associated with greater dietary satisfaction. positive mood and fewer cravings and explicit preference for sweet foods in adults.
The results come in the wake of a 2023 systematic review of evidence from the WHO which suggested that replacing free sugars with sugar-free sweeteners does not appear to help control weight in the long term and could increase the risk of various health problems such as diabetes type 2 and cardiovascular disease, although the report highlighted uncertainty about the evidence between sweeteners and disease outcomes.
“Weight maintenance after weight loss is difficult to achieve and our findings support the use of S&SEs found in many foods and beverages worldwide as alternatives to sugary products to help control weight in overweight adults.” says study leader Professor Anne. Raben from the University of Copenhagen in Denmark. “The findings also provide important information to address controversies about potential adverse health effects. Until now, safety data have generally come from animal studies using doses of sweeteners much higher than usual human intake.”
S&SE have very high sweetening power, but contribute little or nothing to energy intake. Natural and synthetic sweeteners such as aspartame, stevia and saccharin are commonly added to products by the food and beverage industry to reduce sugar content and are consumed by millions of people around the world every day, for example in soft drinks, desserts and breakfast foods.
However, the safety of these food additives and their use in appetite and weight control has been hotly debated, and little is known about the long-term effects of S&SE on eating behavior.
Sweeteners promise weight control
To provide more evidence, researchers from the SWEET (Sweeteners and sweetness enhancers: Prolonged effect on health, obesity and security) project conducted a one-year randomized controlled trial to investigate whether prolonged use of S&SE as part of a healthy low-sugar H diet could improve weight loss maintenance after rapid weight loss, as well as benefit risk markers for type 2 diabetes and cardiovascular disease compared to not consuming S&SE.
Participants also completed questionnaires (at baseline and after 2, 6 and 12 months) to assess the effect of S&SE on dietary satisfaction, control of overeating, explicit and implicit food preference, eating behavior, physical activity and quality of LIFE.
The trial recruited 341 overweight or obese adults (aged 18-65 years, 71% female, body mass index (BMI) ≥25 kg/m2) and 38 overweight children (aged 6-12 years, 60% girls, BMI- age >85th percentile) from Denmark, Spain, Greece and the Netherlands via websites, social media, newspapers and registries.
During the first 2 months of the trial, adults were instructed to follow a low-energy diet (the Cambridge weight plan) with the goal of achieving at least 5% weight loss. The children received dietary advice to maintain body weight.
Over the next 10 months, participants were randomized to either a healthy diet with less than 10% of energy from added sugar allowing foods and beverages with S&SE (S&SEs group), or a healthy diet with less than 10% of energy from added sugar not allowing food and drinks with S&SE (sugar group).
At the start of the trial and after 2, 6 and 12 months, participants took part in clinical survey days to measure weight change, children’s BMI-for-age z-score (a measure of how many standard deviations a child has O BMI is above or below the mean BMI for their age and sex, anthropometrics, and risk markers for T2D (eg, glucose and hemoglobin A1c) and CVD (eg, cholesterol).Participants also completed questionnaires food frequency and urine samples were collected to measure S&SE, fructose and sucrose biomarkers to measure compliance.
As planned, intake of sugar-rich foods and drinks decreased in both groups during the trial, but significantly more in the S&SE than the sugar group. At the same time, intake of S&SE products increased in the S&SE group and decreased in the sugar group. These results were confirmed by urine biomarker analyses.
Intention-to-treat analyzes (including 277 adults who successfully lost 5% or more body weight after the 2-month weight loss period) found that those consuming S&SE had slightly better weight loss maintenance after 1 year than the sugar group (mean weight loss – 7.2 kg vs -5.6 kg making a difference of 1.6 kg).
Furthermore, in 203 participants who completed all clinical surveys, risk markers for type 2 diabetes and cardiovascular disease did not differ between groups.
No differences in BMI-for-age Z-score or other outcomes were observed among the 22 children who completed the trial. A larger study in more children will be needed to determine any possible effect, the researchers say.
Sweeteners reduce cravings for sweet foods and improve well-being in adults
In further analyzes of eating behavior, the researchers found that adults in the S&SE group reported greater dietary satisfaction when eating out, increased positive mood, and lower sweet food cravings at 6 months than the sugar group. In contrast, adults in the sugar group had a greater preference for sweet than salty foods at 6 months and 12 months. However, there were no differences between groups in reported physical activity or quality of life.
In children, replacing sugar-sweetened foods and beverages with sugary products had no effect on eating behavior or physical activity. However, the inclusion of S&SEs appeared to benefit children with high levels of dysregulated eating (eating in response to the palatability of food [tastiness] and the possibility of overconsumption).
As co-lead author Ms Clarissa Dakin from the Appetite Control and Energy Balance Research Group at the University of Leeds, UK explains, “Our findings suggest that including low or no energy sweeteners may benefit children who show high levels of controlled food. For these children, being allowed to consume S&SE resulted in lower levels of binge eating at 12 months compared to children who were not allowed to consume S&SE. This benefit was not found for children with lower levels of uncontrolled eating. these findings provide important information for the ongoing re-evaluation of food additive sweeteners by the European Food Safety Authority and other health organizations worldwide.”
Professor Jason Halford, Head of the School of Psychology at the University of Leeds, UK, one of the SWEET co-authors and Chair of the European Association for the Study of Obesity (EASO), says:“The use of low-calorie sweeteners in weight management has been questioned, in part because of the association between their use and apparent weight gain in observational studies, however, it is increasingly becoming clear that this is not the case in long-term studies.“
The authors note that a key strength of the study is that it is a 10-month (long-term) investigation that adds to evidence from previous short-term trials using a weight loss maintenance plan including food and beverages with S&SE. and using daily amounts of intervention products that are feasible and realistic in daily life. In addition, the trial was conducted as a multicenter trial in four countries across Europe.
However, they note some limitations of the study, including that the dropout rate was higher than estimated. However, with 203 completers, statistical power for the primary outcome was 86%, which is considered satisfactory. In addition, they say the children’s results should be interpreted with caution because of the small number of participants. Finally, they looked at S&SEs collectively without distinguishing between individual types, although this was done intentionally to reflect product variation in the market. Selection bias may also have been a factor, as most participants were female, had a higher level of education, and exhibited health-conscious behaviors.
This research represents the pivotal randomized trial of the SWEET project. Professor Jo Harrold (University of Liverpool, UK), one of the co-ordinators of the SWEET project explains, “The EU-funded project Horizon2020 develops and reviews evidence on the long-term benefits and potential risks of replacing added sugar in the diet with S&SE from multiple perspectives. The results of this long-term trial support the use of S&SEs instead of sugar in foods and beverages for weight control. The evidence suggests that there is no cause for concern about the safety of these products in terms of sweet preference, appetite or glucose control. These results add to the body of evidence suggesting that S&SEs can play a positive role in weight management when used judiciously. Other aspects of the project addressed barriers to the development of healthier, low-energy products and the consequent need to revise policy and regulatory approaches. The SWEET Symposium will provide an opportunity to inform industry representatives, consumers and policy makers about the potential benefits of S&SEs for public health and safety, obesity and sustainability.”
