While it’s definitely important to exercise several times a week, it’s unfortunately not the way to lose weight.
Scientist Herman Pontzer lived in northern Tanzania over a summer to study the local Hadza people, and he discovered how our metabolism works.
The Hadza are constantly engaging in physical activity throughout the day, but they are burning the same number of calories as men and women from industrialized populations.
In Pontzer’s book, Burn: The Misunderstood Science of Metabolism, he writes: “We have [got] the science of energy expenditure fundamentally wrong.”
That’s not to say that we should give up exercise — it just won’t make you slim down. “If you start a new exercise programme tomorrow and stick to it religiously, you will most likely weigh nearly the same in two years as you do right now,” he writes. “You should still do it! You’ll be happier, healthier and live longer. Just don’t expect any meaningful weight change in the long term from exercise alone.”
So, how exactly does one lose weight without going crazy at the gym every day?
“I think that’s right, if you had to point your finger at one thing,” he said. “All the research we’ve done in the last 10 years – not just my lab but other people too – points to diet as being the culprit here for obesity. It’s not sloth, it’s the food.”
Pontzer suggested that the Hadza people have got it right: “They stay thin because they eat a diet that doesn’t have these processed foods in it. I think 90 percent of it is that simple.”
“Every diet that works works because it cuts calories,” he added. “There are different ways to do that. There’s no magic. Every diet works if you stick to it.”
However, everyone’s bodies and metabolism are different, so the best diet depends on “your particular reward system and the variety of foods that satisfy you most on the fewest calories,” Pontzer writes.
Additionally, how you think about food can change your eating habits.
“We know that is your brain’s management of your hunger and fullness and satiety, and we know people are wired differently and the genes that contribute to the variation in BMI [body mass index], they’re active in your brain, not in your fat or muscle cells,” he said. “So it’s how you’re wired, it seems, that’s going to affect how fast you feel your metabolism is.”
The Telegraph spoke with Pontzer about how our metabolisms work.