Obesity in ob/ob mice is due to hyperphagia, calorie partitioning as fat, and slower metabolic rate.

“these animals had what you might call a trifecta for obesity they ate more spent less and whatever they stored was preferentially stored as fat”

“the phenotype centered around hyper fascia it's centered around two phenotypes actually that dr. Coleman was able to show primarily the obesity was due to hyperphagia but he also was able to demonstrate by a mechanism sorry I should just clarify for listeners that means excessive appetite yes by excess food intake that was the primary cause of their obesity but he also by using a technique called peer feeding where he would only feed the animal the amount that a normal weight animal would eat that those animals tend to distort our excess calories as fat we sometimes refer to this as partitioning and by another set of experimental maneuvers was able to show that their metabolic rate was slower”

“if you take a lean animal measure how much it's eating give half of that to the ob mouse so you're literally semi-starving it it's anyway yeah and the fellow who did one of the fellows who published these results are douglas coleman”