Overweight or obese people are often told, derisively, that they lack will power. If they chose to, they could just stop eating when satiated. Similarly, thin people passed off their slim frame to their willpower and excellent metabolism.
Here’s the problem. Neither being thin nor being obese is a personality trait.
A new study, published in the journal Cell, reported by The New York Times, has laid to rest this will power claim. A genetic mutation makes some people always feel full. Another mutation of the same gene makes people always feel hungry.
The scientists relied on data collected from half a million people who had submitted their DNA and medical records to the UK Biobank. Those studied were between 40 to 69.
The first study examined people who had always been thin and didn’t really care about food. The scientists discovered that these people carry a genetic mutation that mutes appetite.
The second study examined the genetic risk score for obesity that can predict as young as childhood if the person will be obese later in life.
Both point to a simple truth. Those who are overweight, or struggle to lose weight, simply feel hungrier than those who are naturally thin.
Gene MC4R
At the centre of this puzzle is a gene called MC4R. People with MC4R gene mutations are obese. These mutations destroy satiety, leaving the person always feeling hungry.
According to Dr. Sadaf Farooqi, professor of metabolism and medicine at the University of Cambridge, when one eats this gene switches on, sending a message to the person when one is full. Then it switches off. But in people who carry a mutation of the gene, that signal never really switches off.
Similarly, in people who are always thin, the gene never switches on in the first place, ensuring that these people are never really hungry. Approximately 6 percent of the population carries these mutations.
These findings are significant in that they can introduce newer studies that re look how we examine obesity and health problems arising out of them.
(With inputs from The New York Times)
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