The usefulness of replacement of caloric sugars by low-calorie sweeteners (LCS) for weight management has been questioned on the grounds that the uncoupling of LCS sweet taste and dietary energy may confuse physiological mechanisms, leading potentially to higher energy and sugar intake. The aim of the present study was to determine whether LCS beverages compared to water, when consumed with meals, differ in their effects on energy and food intake in acute trials and after long-term habituation. Ad libitum food intake of 166 (80 women; 86 men) healthy nonobese adults (BMI between 19 and 28 kg/m²), infrequent consumers of LCS was measured in four 2-consecutive-day testing sessions (Day 1 in the laboratory, Day 2 free-living). During the first 3 sessions, held one-week apart, participants were required to drink either water or commercial non-carbonated LCS lemonade (330 ml) with their main meals (randomised cross-over design). On Day 1, motivational ratings were obtained using visual analogue scales and ad libitum food intakes (amounts and types of foods selected) were measured using the plate waste method. On Day 2, participants reported their ad libitum intakes using a food diary. After Session 3, participants were randomly assigned to the LCS habituation group or to the water control group. The habituation (660 ml LCS lemonade daily vs 660 ml water) lasted 5 weeks. The fourth and final test session measured food intakes and motivational ratings after habituation. Water and LCS beverage did not differ in their effects on total energy intake, macronutrient intakes or the selection of sweet foods and on motivational ratings. Similar results were obtained in both LCS-naïve and LCS-habituated individuals.
In line with findings of other studies, the present randomised controlled trial showed that acute or longer-term consumption of low calorie sweetened beverages with meals does not affect overall calorie and food intake nor appetite and hunger, compared to water. Furthermore, the intake of sugar and sweet-tasting foods or drinks was not influenced by the low calorie sweetened beverage versus water in the longer term, and in fact, it was found to be lower in the acute phase in the low calorie sweetened drink group versus the control (water) group. Importantly, these outcomes have been confirmed for both low calorie sweetener “naïve” participants as well as after a habituation period.
The findings of the study by Fantino et al provide further evidence that low calorie sweeteners don’t affect appetite and food intake differently compared to water, and are in contrast with notions that low calorie sweeteners may promote increased calorie intake and body weight gain by uncoupling sweet taste. Contrary to these theories, the consumption of carbohydrates and simple sugars as well as of sweet foods, was decreased in the low calorie sweetened drink group in the acute phase, compared to water, in “naïve” participants. Thus, the results of the present study by Fantino et al show no signs of any disruption of eating behaviours after acute or longer-term exposure to low calorie sweeteners.
Several other works have examined the effect of using low calorie sweeteners in place of sugar and have shown that substitution of sugar for low calorie sweeteners can be an efficient tool to help reduce overall energy and sugar intake and, thus, in weight control. Taken together, the existing evidence from clinical trials shows that low calorie sweeteners do not increase energy and food intake or appetite for sweet taste, and that in line with their intended use, low calorie sweeteners can be a helpful tool when used to replace and help reduce sugar in the diet.