The debate regarding the American "obesity plague" has taken on an increasingly rancorous tone. On one side are those who honestly believe that we cannot repair our imperiled health-care system without addressing the enormous strains placed on that system by the seriously overweight. On the other side are those of a Rubenesque stature who are enraged that they are routinely the targets of catcalls, epithets and even job discrimination, and who have had it up to here with the fatty jokes.

Lost in all this is an appreciation...