Obesity, genetics, and ponderal set point.

A significant proportion of the interindividual variance in human fatness is attributable to genetic factors. This fact is indicated (inter alia) by studies of identical twins demonstrating that the degree of efficiency with which the body uses excess dietary energy for fat storage is, to a considerable extent, inherited. Genetic factors also appear to render particular individuals or groups especially vulnerable to pervasive obesity-promoting influences (excess food and too little exercise) in the environment. If, indeed, much human obesity results from an interaction between a genetically determined disposition to store fat efficiently and a food-laden, overmechanized environment, then preventive and therapeutic strategies should be directed toward (a) helping the susceptible individual protect himself from the "calorie pollution" that surrounds him, and (b) finding pharmacologic agents to modify the inherited metabolic factors that favor excessive fat storage.