SEX DIFFERENCES IN HEDONIC FEEDING IN SPRAGUE-DAWLEY RATS WITH MOTHERS UNDERGOING A HIGH-FAT, HIGH-SUGAR DIET THROUGHOUT PREGNANCY AND LACTATION

The prevalence of obesity remains high globally, with women disproportionately affected; in the United States alone, the prevalence of severe obesity (body mass index ≥ 40) for adult women was 12.1% in 2023, compared to 6.7% for adult men. Maternal obesity has also increased and represents a risk factor for fetal development. Maternal metabolic status during gestation and lactation presents a critical window for programming offspring’s physiology and behavior, and long-term susceptibility to developing obesity. Among the proposed causes of obesity, hedonic feeding is a major contributing factor. It refers to food intake regardless of physiological hunger; instead, it is driven by pleasure and food palatability. Here, we used a single-session behavioral economics (BE) approach to evaluate hedonic feeding in female Sprague-Dawley rats for a high-fat palatable (HFP) reward pre-pregnancy, during pregnancy, and during lactation. BE was also performed on their offspring. We quantified demand elasticity (α), the rate at which demand falls when the effort required increases, and demand at null cost (Q₀), a prediction of consumption at null effort. We determined a significantly higher Q₀ for the HFP reward in mothers during lactation but not during pregnancy. In offspring of HFP-rewarded mothers, females had a higher Q₀ than males, although not statistically significant. Given that in previous studies we had observed significant sex differences in Q₀, not observing them in this study leads us to hypothesize that a high-fat, high-sugar diet throughout pregnancy decreased sex differences in hedonic feeding.