Study shows how hitting gym to lose weight may not be enough

If you’re hitting the gym thinking it’s the ultimate solution for weight loss, it might be time to reconsider your approach. While exercise is undoubtedly important for overall health and fitness, research shows that relying solely on it to shed pounds might not be as effective as you think. A recent study on the Hadza tribe challenges popular belief, offering fresh insights for those looking to lose weight.

Calorie burn in active vs sedentary lifestyles
When Herman Pontzer began researching the metabolism of the Hadza, a modern hunter-gatherer tribe in Tanzania, he expected their calorie burn to be through the roof. With their constant activity like walking, jogging, lifting, and carrying throughout the day, he thought they’d burn far more calories than a sedentary office worker.

However, his 2012 study revealed something unexpected. When comparing Hadza’s daily energy expenditure (adjusted for body size) with that of an average office worker in the United States, the results were almost the same. Despite their active lifestyle, the Hadza weren’t burning significantly more calories than someone working at a desk.

What is ‘constrained total energy expenditure mode’
“That was unexpected,” said Pontzer, now an evolutionary anthropologist at Duke University and author of the 2021 book Burn, which explores the science of metabolism. The results were so surprising that they led him to create a new theory about how we burn calories, known as the “constrained total energy expenditure model.”

This theory suggests that our bodies and brains can adjust the number of calories we burn by slowing down or even shutting down certain biological functions when we’re more active, ultimately keeping our total calorie burn within a narrow range.

“We’ve studied people who are extremely active,” including marathon runners crossing the U.S., Pontzer explained, “and those who are very sedentary, and it turns out they burn about the same number of calories.” This insight helps explain why many people don’t lose significant weight from exercise alone, even though it improves their health.