Diet-induced obesity model

The diet-induced obesity model (DIO model) is an animal model used to study obesity using animals that have obesity caused by being fed high-fat or high-density diets.^[1] It is intended to mimic the most common cause of obesity in humans.^[2] Typically mice, rats, dogs, or non-human primates are used in these models. These animals can then be used to study in vivo obesity, obesity's comorbidities, and other related diseases. Users of such models must take into account the duration and type of diet (e.g. hydrated gels vs. dry pellets) as well as the environmental conditions and age of the animals, as each may promote different bodyweights, fat percentages, or behaviors.^[3]

Driven by the worldwide epidemic of obesity, particularly in the Western world, the DIO model has been integral in understanding the relationship between high-fat/high-density diets and obesity, including the discovery of Akt and mTOR, signals in the body linked to obesity and insulin resistance.^[4] However, while many insights into the control of obesity have come from experiments since its introduction in 1949, the use of animal models does restrict our ability to extrapolate findings to humans.^[5]