The Biggest Loser Got This Completely Wrong About Fat Loss

I never really watched The Biggest Loser, so maybe there were some redeeming qualities. But from what I remember, it was a pretty terrible depiction of how we should approach weight loss.

On the surface, it looks like a transformation story. People show up overweight, train hard, eat less, lose weight, and ultimately become better versions of themselves.

But when you look at how the show was structured to maximize entertainment—grueling “last chance” workouts, junk food temptations in exchange for a call to a loved one, and weigh-in rewards and penalties—you start to see how twisted the concept really was.

Is anyone really surprised that most contestants gained the weight back?

As it turns out, not only is abuse a poor model for weight loss, research by Herman Pontzer and colleagues suggests that exercise isn’t all that effective for weight loss anyway.

When Pontzer and his team studied highly active hunter-gatherers, they found that these populations didn’t burn significantly more calories per day than sedentary Western populations—despite dramatically higher levels of daily physical activity.

This runs counter to the traditional belief that exercise simply adds calories burned on top of everything else. Instead, total daily energy expenditure appears to level off at higher workloads.

In other words, a runner logging 50 miles per week may not burn dramatically more total calories than someone sitting at a desk all day.

The Missing Piece

Total energy expenditure is the sum of everything your body does—movement, metabolism, immune function, hormone production, cellular repair, and more.

What emerging research shows is that when activity levels increase, the body compensates by dialing back energy spent elsewhere.

That includes:

• Reducing non-essential energy expenditure
• Suppressing physiological processes (immune, hormonal, reproductive)
• Decreasing spontaneous movement (NEAT)
• Becoming more metabolically efficient

This is often referred to as reduced somatic maintenance—your body temporarily pulls back on repair and upkeep to stay within its energy budget.

While that might not be ideal if your goal is fat loss, it makes a lot of sense from an evolutionary perspective. A system that increased calorie burn indefinitely would be a survival risk in environments where food wasn’t guaranteed.

In practical terms, when energy output increases, less energy is available for resting metabolism, hormone production, immune activity, recovery, and tissue repair.

(Pontzer H, et al. Constrained Total Energy Expenditure and Metabolic Adaptation to Physical Activity in Adult Humans.)

The Metabolic Ceiling

But what about the extremes—like the Tour de France or ultramarathons?

Research by Andrew Best on elite endurance athletes shows there’s a limit to how much energy humans can burn over time.

Even when athletes are expending thousands of calories per day, energy expenditure eventually plateaus. The body simply can’t keep adding output indefinitely.

Over time, humans appear to sustain energy expenditure at roughly 2.5 times their basal metabolic rate. Athletes can exceed this for short periods (up to about 30 weeks), but eventually, they must pull back to recover.

You Should Still Exercise

This challenges one of the most common assumptions in fitness—that you can continually increase calorie burn to drive weight loss.

The reality is more nuanced. Activity does increase energy expenditure, but not in a linear fashion. Over time, the return diminishes.

That doesn’t mean exercise doesn’t matter. It remains one of the most powerful tools we have for:

• Improving metabolic health
• Maintaining muscle mass
• Building strength and resilience
• Reducing pain
• Enhancing performance

And while it may seem like a downside, some of the reductions in immune activity and inflammation may actually play a regulatory role in keeping those systems balanced.

So instead of thinking about exercise as a way to burn calories, it’s more useful to think of it as a way to build a more capable system—one that supports whatever you enjoy doing.

And if you stay consistent, it’s what allows you to keep doing those things well into your later years.

Next week, I’ll dive into how this research impacts recovery—and why it matters more than most people think.

Here are some references if you're interested in learning more:

• Podcast with Dr. Herman Pontzer
• The Exercise Paradox by Dr. Herman Pontzer
• Podcast with Dr. Andrew Best

Originally published as Movement #298