People who want to lose weight need to cut calories, not increase their exercise expenditure. Although exercise is necessary for overall health, research shows increasing our movement can't make us thin. These findings come from years of research on cultures that endure strenuous physical activity each day who don't have a lot of food.
A prime example would be the Hazda people living in southeast Africa. Duke University researcher Dr. Herman Pontzer and his team first examined the Hazdas' daily energy output ten years ago.
"Of course they're so physically active," Dr. Pontzer told CBN News, "Men are walking ten miles a day, women are walking six or eight miles a day. We were sure they'd be burning so many more calories than people in the US and Europe and industrialized populations."
They were wrong.
Knocked Their Socks Off
The researchers witnessed and documented extreme levels of exercise among the hunter-gatherer people group. However, using highly advanced and accurate measurement techniques, they discovered the Hazdas didn't burn more calories than their couch-potato counterparts half a world away.
"Instead what we found," Dr. Pontzer said, "It knocked our socks off, was that actually, Hadza men and women, who are incredibly physically active, burn the same number of calories as we are here in the US."
"On average, men burn about 3,000 calories a day, women burn about 2,500 a day just by virtue of being a little bit smaller," he said.
In his book, Burn: New Research Blows the Lid Off How We Really Burn Calories, Lose Weight, and Stay Healthy, Dr. Pontzer lays out a number of similar studies on calorie expenditure in different cultures around the world over the last decade that all reached the same startling conclusion: people who exercise more don't burn markedly more calories than people who hardly exercise at all.
"What we find is that people who are really physically active are burning the same number of calories as people who are less active, in fact, even more sedentary," Dr. Pontzer said.
How Can This Be?
To help explain this metabolic mystery, scientists discovered that regardless of how much we exercise, the human body's daily calorie expenditure primarily consists of burning most of its energy in ways that keep our bodies operating.
"Your immune function, your reproductive function, just staying alive day-to-day," Dr. Pontzer said, adding that things like thinking, breathing, and digestion burn a lot of calories.
Dr. Pontzer says he and his fellow scientists learned that when people exercise a great deal, the body's metabolism shifts in a way that doesn't allow a person to burn more calories.
"Your body makes adjustments in those activities and how much it's spending on those activities to make room for physical activity," he said.
Although excess exercise prevents people from losing weight, which many overweight westerners may view as a drawback, since these cultures have an abundance of food, it also prevents people from starving to death in cultures that don't have a lot of high-calorie foods.
Watch What You Eat
In light of this discovery, how does a person drop those unwanted pounds? Pontzer says the answer is easy to understand but difficult to implement.
"So if you want to manage your weight, you want to focus on diet," he said.
Scientists tell us we should look to the old adage, "calories in versus calories out." In other words, our weight is determined by the difference between how many calories we consume versus how many calories we burn.
Dr. Pontzer says since we now understand the number of calories we burn is relatively fixed, in order to manage our weight, we need to focus on the variable that is flexible: the number of calories we consume. Surprisingly, however, he discourages people from trying to count them because people tend to make mistakes.
"It's actually really hard to pay attention to the calories you eat every day," he explained, " You forget. Or you sort-of misestimate how much you eat. It happens to everyone."
Instead, he recommends daily weighing and adjusting food intake based on what the scale reads.
If the number on the scale is higher than you'd like, cut back on what you're consuming. Dr. Pontzer says the best place to start is by avoiding processed items such as sugary drinks and prepared packaged foods.
"They're literally engineered for you to over-consume," he said.
Dr. Pontzer says people who are trying to lose weight should replace processed foods with whole foods. These are items that are close to their original state[s], such as fresh produce, meat, fish, and dairy. Many of these items can be found on the exterior of the grocery store. They are foods that are generally lower in calories than processed foods while at the same time make you feel fuller than processed foods.
Pontzer stresses that even though exercise is not necessary to lose weight we still need to exercise. Physical activity helps fight disease in many ways such as lowering inflammation, improving brain function, and strengthening the cardiovascular system.
Your health is important. Do you have questions about nutrition, weight loss, boosting immunity or medicine? Learn more here!