Non-nutritive sweeteners, as an alternative to sugar, may lead to weight reduction

Laviada-Molina H, Molina-Segui F, Pérez-Gaxiola G, et al. Effects of nonnutritive sweeteners on body weight and BMI in diverse clinical contexts: Systematic review and meta-analysis Obes Rev. 2020; 21:e13020.

Review question

What is the effect of non-nutritive sweeteners on body weight in people across various age groups, body weight categories, and diet restrictions, compared to other caloric and non-caloric options?

Background

Obesity, an excess of body fat, is a major public health concern that increases the risk of developing serious health conditions and complications, including heart disease, diabetes, and cancer. Non-nutritive sweeteners (also referred to as non-caloric sweeteners, very low-calorie sweeteners, or artificial sweeteners), such as aspartame and stevia, are sugar substitutes used to sweeten food and beverages. Past research on non-nutritive sweeteners has been mixed, with some studies suggesting that they may promote increased food intake, leading to weight gain, and others suggesting that they may help with weight loss. Given the lack of expert consensus on the issue, a comprehensive analysis that takes into account newly published research is needed.

How the review was done

This is a systematic review and meta-analysis of 20 randomized control trials published between 1976 and 2019. Key features of included studies:

• Participants were children, adolescents, and adults who were either of normal weight, overweight (Body Mass Index [BMI] ≥25 kg/m²), or obese (BMI ≥30 kg/m²).
• Participants consumed one or more of the following non-nutritive sweeteners: aspartame, stevia, sucralose, saccharin, and RebA. Participants were either on a weight reduction diet or unrestricted diet.
• Researchers measured changes in body weight or BMI.
• Results were compared to those who used caloric comparators (e.g., sucrose) or non-caloric comparators (e.g., water, placebo, or nothing).
• Studies ranged from 12-77 weeks in length.

What the researchers found

Overall, the results showed that the use of non-nutritive sweeteners may lead to anywhere between small to moderate reductions in weight/BMI. However, the effect differed based on age, weight, and diet type. More specifically, non-nutritive sweeteners may lead to weight/BMI reductions in: adults but not children/adolescents; the population living with overweight or obesity but not the normal weight population; and those on an unrestricted diet but not those on a weight reduction diet. In terms of comparators, non-nutritive sweeteners were more effective than sucrose, but were not more effective than water, placebo, or nothing. The certainty of the evidence ranged from very low to moderate, meaning that the findings from future studies may change these results. Higher quality evidence is needed to provide more definitive guidance. The majority of studies included in the review occurred over a period of less than 48 weeks. As such, more research is needed on the long-term impacts of non-nutritive sweeteners.

Conclusion

Non-nutritive sweeteners, may lead to weight reduction, especially in adults, people living with overweight or obesity, people on an unrestricted diet, and when compared to sucrose as a substitute.