Fatness and obesity of the parents of obese individuals.

As shown in 1419 pairings of obese probands with their parents drawn from a larger series of greater than 9000 proband-parent pairings, the fathers and mothers of obese probands are of increased fatness level (+0.27 Z scores) and more often obese than expected (odds ratio 1.50 overall). However, the tendency towards increased fatness and a greater prevalence of obesity among the parents of obese probands bears a curvilinear relationship to the age of the proband, being least when the probands are young, peaking when the sons and daughters are teen-agers, and declining thereafter. Parents of lean probands in turn tend to be lean themselves (averaging -0.25 Z scores) and least often obese when their progeny are teen-aged. As shown in a two-generational context, familial obesity is best demonstrated in adolescents and their parents, either reflecting years spent in common or a specific etiology for adolescent-onset obesity.