The impact of high-fat, obesogenic diets on brain volume in a commercially available mouse model of fatty liver disease

The obesity pandemic poses significant health challenges, despite recent advancements in weight loss medications. Mouse models fed obesogenic diets serve as invaluable tools for dissecting the pleiotropic mechanisms underlying weight gain. Here, we utilize these models to analyze brain morphometrics using MRI techniques, inspired by similar findings in human studies linking obesity to brain volume changes. We hypothesize that the mouse model of obesity will exhibit brain volume alterations akin to those observed in obese humans, potentially shedding light on the neurological implications of obesity. To test our hypothesis, mice were provided free access to either regular chow or a diet consisting of high fat and high sugar and MRI scans for total brain volumes as well as volumes of specific brain regions were estimated and compared between obese and control mice. We found that obesogenic diets resulted in ∼13% greater weight gain compared to control chow diets. MRI brain scans revealed reduced total brain volume in obese mice that trended towards significance. In contrast, analysis of specific brain volumes showed an increase in neocortical regions of obese mice, that were significant when compared to controls. In conclusion, diet-induced obesity mouse models are a readily available avatar for studying the obesity epidemic, with significant increases in body weight within a reasonable timeframe. While weight gain among individual mice fed obesogenic diets showed some variability, MRI brain scans were able to reveal significant differences, especially within different anatomical regions of the brain.