According to the University of Michigan, about 90% of people who lose significant amounts of weight, whether through diets, structured programmes or even drastic steps such as gastric surgery, ultimately regain just about all of it.
Why is this? Scientists believe that the answer lies in the workings of our metabolism.
When someone begins a new diet, we know that metabolism initially drops – because we are suddenly consuming fewer calories, the body responds by burning them at a slower pace, perhaps an evolutionary response to prevent starvation – but what then happens over the following weeks, months, and years, is less clear.
“Does metabolism continue to go down, more than it should,” asks [researcher Susan] Roberts, “or does it initially go down, and then bounce back?”
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The implications for how we tackle obesity could be enormous. If metabolism drops and continues to stay low during weight loss, it could imply that dieting triggers innate biological changes that eventually compel us to eat more. If it rebounds to normal levels, this suggests that weight regain is due to the recurrence of past bad habits, with social and cultural factors tempting us to go back to overeating.
