People on all sorts of diets have successfully lost weight. But check in after 6 months and many are back where they started. It’s as if our bodies are programmed to regain the pounds. A new review explores energy balance and the relationships between obesity, inactivity, and health. The bottom line? Time to get moving.
When you think of obesity, what comes to mind?
Is it disease? Poor diet? Laziness?
What about adaptation?
Consider a 125lb woman and a 250lb man. Who do you think expends more energy walking from point A to point B?
What if obesity’s just the body’s response to life in an increasingly sedentary environment?
According to a new review published in US Endocrinology, this view of obesity has some merit. Obesity isn’t so much the problem, but your body’s stab at a solution.
Drs. James Hill, Holly Wyatt & John Peters believe the problem actually revolves around energy balance—the straightforward idea that calories coming in should match calories going out. Lose that balance and you’ll likely gain some weight.
Of course, weight loss also requires an energy imbalance: moving more than you eat. What makes weight loss so difficult is your body responds very strongly to this kind of imbalance. Not only are you struck with hunger pangs, but your body actually reduces your resting energy expenditure to compensate for the decrease in energy coming in.
Why does it do this?
Because for most of human history, this kind of imbalance—moving all the time to find limited food—was a major problem.
Unfortunately for us modern humans, when you eat more than you move, your body’s response isn’t nearly as strong. This, again, is the slow and steady weight gain. Your body requiring you to expend more energy with each visit to the fridge.
Worldwide, there are 1.1 billion overweight adults. Given the changes to our diet and activity levels over the last decades, the obesity epidemic should be even worse. So the human body is adapting. But we’re demanding a sprint when evolution tends to crawl.
So how can we solve this problem, without leaving our bodies to their evolutionary devices?
More physical activity.
Ever notice how that friend of yours who exercises every day can seemingly eat whenever and whatever without significant changes in weight?
Here’s the scientific explanation:
There’s a line in the sand when it comes to physical activity. Cross it and you enter a zone where—without expanding your waistline—your body can easily regulate increased intake à la your Thanksgiving feast.
If you fail to reach that line and you don’t want to upgrade your wardrobe, you’ll have to rely on unsustainable diets (key word: unsustainable).
Here’s an unsavory statistic: over the long-term, one-third to two-thirds of dieters regain more weight than they initially lost.
As the publication reports, it’s all because human physiology is biased toward finding energy balance at high intake and high expenditure.
In short, halting obesity requires more than just watching how much we eat. It requires watching how much we move. Because, while dieting can help you drop the pounds, physical activity is what will keep you from picking them back up.
For more of the science behind this energy balance review, check out Scizzle.
Hill, J.O., Wyatt, H.R., Peter, J.C. 2013. The Importance of Energy Balance. US Endocrinology Vol. 9:1, p.27-31.