A NEW study suggests that obesity is irreversible if not caught early enough – and that people who are fat in childhood may end up ‘programmed’ to be fat for life.
Experiments at the University of Michigan and the National Council of Science and Tecnology (CONICET) in Argentina showed that the longer mice remained overweight, the harder they found it to shift the pounds for good.
That’s because the animals reset their body weight set point to ‘normal’ when obese or overweight.
The boffins flipped a genetic switch that controls hunger using mice at several different ages.
Turning on the switch right after weaning prevented those mice from overeating and ever becoming obese.
Similarly, mice that remained at a healthy weight into young adulthood by strict dieting alone were able to maintain normal weight without dieting after turning on the switch.
But chronically overfed mice with the earliest onset of obesity never completely returned to normal weight after flipping the switch – despite reducing their food intake and increasing activity.
Senior author Professor Malcolm J. Low said: “Somewhere along the way, if obesity is allowed to continue, the body appears to flip a switch that reprogrammes to a heavier set weight.
“Our model demonstrates that obesity is in part a self-perpetuating disorder – and highlights why most adults find it difficult to maintain meaningful weight loss from dieting and exercise alone.