Reward impulsivity is linked to addictive-like behaviors towards sweet food and sugary drinks but not fatty food

Overconsumption of hyperpalatable food is a worldwide problem. Although many previous studies have shown the link between monetary delay discounting and propensity to overconsume food, the studies did not focus on the link between delay discounting and various subcategories of palatable food. In the present study, we investigate the link between the individual propensity to choose smaller immediate rather than larger delayed reward and the degree of problematic eating behavior for five types of palatable food (sweets, sugary drinks, fatty food, salty snacks, and starchy food). The delay discounting task was used to measure propensity to choose immediate rather than delayed rewards, while the degree of addictive-like behavior was measured using the modified Yale food addiction scale (mYFAS) for each food category. Both model-free and model-based analysis showed that there is a significant correlation between the addiction score for sweet food and the tendency to choose smaller immediate rather than larger delayed rewards. A model-based analysis showed the same significant correlation for sugary drinks. However, no such correlation was observed for other food categories (fatty, salty, or starchy food), suggesting that reward impulsivity may play different roles in addictive-like behavior towards various food categories.