Higher Alcohol Preference is not Necessarily Linked to Higher Consumption of Palatable Food in Rats

Alcohol use disorder (AUD) is a chronic relapsing disorder afflicting millions of people worldwide. Malnutrition is frequently associated with AUD, and it could be a result of reduced nutritional intake and impairment in the absorption/metabolism of nutrients because of excessive alcohol drinking. Interestingly, a higher consumption of high-calorie/palatable foods is reported in recovering alcoholics who have stayed sober. However, it is unclear if the higher calorie content or rewarding properties of these palatable foods account for a protective effect in these conditions. In the present study, we evaluated the palatable food intake in male and female alcohol-preferring (P-rats) and compared it to alcohol non-preferring rats (NP-rats). Importantly, alcohol-preferring (P-rats) were selectively bred for higher alcohol preference and are a well-characterized model of alcoholism. A group of P- and NP-rats received a high-fat diet (40% fat) on four separate days over a two-week period, and 24-hour caloric intake and changes in body weight were recorded. Unrestricted standard chow and water were available to all groups for the entire study duration. Total caloric intake in both P- and NP-rats was significantly increased on HFD access days compared to chow-only days, an effect observed in both males and females. Further analysis revealed that total caloric intake in P-rats was significantly lower compared to NP-rats, an effect more significant and pronounced in female rats. Furthermore, body weight increase during this period was significantly lower in P-rats than in NP-rats, an effect more significant and pronounced in male rats. These data not only document important sex-based differences and differences in palatable diet intake between alcohol-preferring and non-preferring rats, but also highlight that higher alcohol preference does not necessarily equate to a higher intake of high-calorie/palatable food.