The Biology and Genetics of Obesity
Many years ago, I came up with a sure way to lose weight –
take in fewer calories than you burn. What could be simpler?
I was not alone. A study of more than 1100 adults found that
61% of U.S. adulates that “personal choices about eating and exercise” were the
cause of overweight.
Over the past few years, data have been accumulating that
indicate that while I might be correct in many, even most cases, there was a
group of people with whom my plan would not work.
Today, molecular genetics is central to obesity research. In
2007, Mark McCarthy, Andrew Hattersley, and their colleagues in the UK
identified a common variant in FTO, the fat-mass and obesity–associated gene,
and gene hunters aided by the use of next-generation–sequencing technology
continue to identify gene variants or mutations. These studies reinforce what
some researchers have been insisting for more than a century: that obesity is
innate in some people, that for them weight regulation is not governed by a
uniform tally of “calories in–calories out,” Genetic predispositions, in tandem
with the development of food environments that facilitate overeating and built
environments requiring minimal energy expenditure, may help explain why so many
Americans are obese today.
Chin Jou, N Engl J Med 2014; 370:1874-1877