Decreasing the Consumption of Foods with Sugar Increases Their Reinforcing Value: A Potential Barrier for Dietary Behavior Change

Background: The Dietary Guidelines for Americans (DGA) have recommended reducing added sugar intake since its inception in 1980. Nearly 40 years later, added sugar consumption still exceeds 2015-2020 DGA recommendations among most of the population. The reinforcing value of food influences eating behaviors, and foods high in added sugars are highly reinforcing. Restricting intake of foods high in added sugars as part of a low-sugar diet may increase their reinforcing value such that reducing consumption may be difficult to maintain. If so, this would present a mechanistic barrier to making the necessary dietary changes to meet 2015-2020 DGA recommendations. Purpose: To determine whether the relative reinforcing value of foods high in added sugars is altered when reducing intake of all foods high in sugars. Methods: Obese (n=19) and normal weight (n=23) men and woman who habitually consumed over 10% of their calories from added sugars completed the study. Reinforcing value of foods high in added sugars was measured via progressive ratio schedules of reinforcement before and on day 7 of a weeklong controlled feeding intervention where added sugars comprised 2.5% to 4.0% of daily calories and total sugars 7.3% to 8.6% of daily calories. Results: The reinforcing value of foods high in added sugars increased (P<0.01) after consuming a diet low in total added sugars for 1 week in both obese and normal weight participants. Conclusion: Adhering to a low-sugar diet for 1 week increases the reinforcing value of foods high in added sugars. Future studies should examine whether consuming a diet low in added sugars, but not other sugar, increases reinforcing value of foods high in added sugars and whether high–added sugar food reinforcement returns to baseline after longer-term reductions in added sugars.