Do Diet Beverages Increase Preferences for Sweet Foods and Beverages?
Reducing consumption of sugar-sweetened beverages is a strong evidence-based recommendation of the Dietary Guidelines for Americans. Water and nutritious beverages such as low-fat or nonfat milk are obvious alternatives to beverages that are sweetened with high-fructose corn syrup (HFCS), sucrose, or other form of added sugars. Many Americans realize the importance of reducing sugar intakes for themselves and their children, but there is much confusion and controversy over the potential value of diet beverages. Until now, there has been a concern that the sweet flavor of diet sodas and other beverages containing low-calorie sweeteners may increase individuals’ preference for, or intake of, other sweet/calorie-laden foods and ultimately contribute to overall weight gain.
A new study from the University of North Carolina at Chapel Hill is the first randomized clinical trial to examine the effect of diet beverages on dietary patterns and energy/calorie intakes. Subjects (mostly women) were randomly assigned to three groups and followed for six months. One group of 106 subjects substituted water for caloric beverages, another group of 104 subjects substituted diet beverages, and a third group was not given either substitution. Both the water group and the diet soda group lost about 2- 2.5% of their body weight on average, as reported in an article published in 2012. The current article focused on dietary intake patterns and food choices. When compared to the diet soda group, the water group increased intake of fruit and vegetables and decreased intake of protein foods, grains, and mixed/frozen/fast-food meals but the diet beverage group had greater reductions in desserts. Overall, the authors state “it was difficult to find meaningful differences between water and the diet beverage groups” because both groups were trying to reduce their food/calorie intakes. The main outcome was that this study’s findings do NOT support the argument that diet beverages cause weight gain by increasing people’s desires or tendencies to consume other sweet foods.
There are many arguments for and against recommending diet beverages as appropriate substitutions for beverages containing added sugars such as HFCS and sucrose. One of those arguments – the suggestion that diet beverages may increase overall calorie intake by stimulating appetites or cravings for other sweet foods – is weakened by this study. The overall topic still unsettled and the following quote from the Dietary Guidelines for Americans’ Advisory committee’s 2010 report is still a prudent guide for educators.
“Moderate evidence shows that using non-caloric sweeteners will affect energy intake only if they are substituted for higher calorie foods and beverages. A few observational studies reported that individuals who use non-caloric sweeteners are more likely to gain weight or be heavier. This does not mean that non-caloric sweeteners cause weight gain rather that they are more likely to be consumed by overweight and obese individuals…The replacement of sugar-sweetened foods and beverages with sugar-free products should theoretically reduce body weight. Yet many questions remain, as epidemiologic studies show a positive link with use of nonnutritive sweeteners and BMI. Additionally, whether use of low calorie sweeteners is linked to higher intake of other calories in the diet remains a debated question.” (page D5-30).
Tate DF, Turner-McGrievy G, Lyons E, Stevens J, Erickson K, Polzien K, Diamond M, Wang X, Popkin B. Replacing caloric beverages with water or diet beverages for weight loss in adults: main results of the Choose Healthy Options Consciously Everyday (CHOICE) randomized clinical trial. Am J Clinical Nutrition 2012;95:555–63.
Piernas C, Tate DF, Wang X, Popkin BM. Does diet-beverage intake affect dietary consumption patterns? Results from the Choose Healthy Options Consciously Everyday (CHICE) randomized clinical trial.
Report of the DGAC on the Dietary Guidelines for Americans, 2010, http://www.cnpp.usda.gov/Publications/DietaryGuidelines/2010/DGAC/Report/D-5-Carbohydrates.pdf.
By Susan Nitzke: UW-Extension Nutrition Specialist, UW-Madison Professor Emeritus