Abstract: Obesity has become a serious threat to human health, with excessive intake of sugar being one of the major causes of obesity. Therefore, replacing high-calorie sugar with low-calorie functional sweeteners or sugar substituents is a popular dietary choice for the prevention and management of obesity. However, the relationship between functional sweeteners and obesity is complex, and no definitive conclusion has been reached. This is because the effect of functional sweeteners is influenced by various factors, including the type and dosage of functional sweetener, as well as individual differences such as gender, health status and gut microbiota composition. In this article, we review the effect of common functional sweeteners on energy metabolism, fat metabolism and the gut microbiota in the body. Furthermore, we summarize the current studies on the effect and mechanism of functional sweeteners on obesity hoping to provide a reference for better selection or application of foods and beverages containing non-nutritional sweeteners in the future.

Key words: functional sweetener; obesity; energy metabolism; intestinal microbiota; mechanism