The Washington Post reports the results of a Rutgers study finding inadequate amounts of a particular hormone in the brain leads to overeating. The hormone, glucagon-like peptide-1 or GLP-1, is secreted by both the brain and small intestine and tells the brain when you've had enough food.
The study, done on mice, found when mice had too little GLP-1, they overate and favored fatty foods. Obviously we're a long way from a brain-targeted treatment based on GLP-1. Mice which got extra GLP-1 tended to avoid fatty foods.
A hormone level determinant could explain why obesity tends to run in families. Producing lots vs. little of it would tend to be genetically determined.
The ability to store nutrients as fat was a pro-survival trait in humans for hundreds of thousands of years; our ancestors experienced periodic famine, particularly in late spring before the crops ripened. Of course fat storage is pro-survival no longer as today most of us are complete strangers to famine.
