The Power of the Extreme in Elucidating Obesity

Despite the worrisome statistics that 16% of children in the United States are obese and that the number of adults with a body-mass index (the weight in kilograms divided by the square of the height in meters) of 50 or more has increased by a factor of 6 in the past 10 years, no simple environmental explanation for the obesity epidemic has proved valid. Many health advisers view obesity simply as a reflection of unwise personal lifestyle choices, and many would probably be surprised to learn that adiposity is one of the most heritable of human traits. Data from recent . . .