When we think about what strategy to take to lose weight, we think get a gym membership, hire a trainer, do lots of cardio and replace all those cookies and pizzas with healthier options. Exercise has been synonymous with weight loss in popular culture since before Dr. Jonas Gustav Wilhelm Zander popularized the connection between exercise and well-being and invented the Gymnasticon, the world’s first piece of exercise equipment in the late 1800’s. As it turns out though, what you eat and how much you exercise aren’t nearly as important as how much you eat. In fact, it’s not even close. While exercising and eating healthy have enormous health benefits and certainly help with weight loss, when it comes to purely losing weight, eating less total calories, regardless of what you are eating, is overwhelmingly the biggest predictor of bodyweight.
To understand weight loss, let’s separate it completely from health. There are skinny people in poor health and there are obese people in excellent health. Western culture has embedded in all of us that thin = healthy and fat = unhealthy. Even the World Health Organization (WHO) directly correlates health with body weight by using Body Mass Index (BMI). The WHO states that for adults, a healthy BMI for a person who is 5’6 is 154lbs or under. This is, however unequivocally false. While weight can be a good indicator of health, it is not, in and of itself, the sole predictor. This neglects many other heath factors and is like saying the bigger the diamond, the more it is worth. While size (carat) is important, color, clarity and cut are equally as important to a diamonds value.
Now back to weight loss. From 30,000 feet, there is only one thing that determines weight loss, and that is if your body uses more total calories than you eat, you will lose weight, without exception. The two ways we can control this is by eating less calories, or exercising and burning more calories. While the kinds of foods we eat are important, and eating a ‘healthier’ diet has countless benefits as well, when it comes to losing weight, they combine for a small piece of the pie.
To us and our palates, there is an enormous difference between orange soda and orange juice, but to the body, 100 calories from orange soda is the same amount of energy as 100 calories from orange juice. For weight loss, calories are calories are calories. The fact that one has vitamin C and healthy fiber and the other is refined corn syrup doesn’t matter all that much. The health effects are very different between the two, but you will ultimately weigh less if you drink 100 calories worth of orange soda instead of 200 calories of orange juice.
Exercise as well has heaps of health benefits. This can’t be overstated. People who exercise, on average, live longer, feel better, and have less health complications than those who do not exercise. For weight loss however, its impact is far overemphasized. Statistically, in the first eight years of the 2000’s, the percentage of Americans who were “sufficiently active” increased, while the percentage of obese Americans also increased. Wait, what?? Yes, we both exercised more and got fatter. This result has been validated by a number of studies on obesity. Studies have consistently been unable to prove that a physically active person is any less likely to gain weight than a sedentary person. Further, a meta-analysis looking at the relationship between body fat and physical activity in children found that the two are only loosely correlated.
There’s several reasons why exercise are not the best way to lose weight:
Exercise increases your appetite: While we exercise hard it feels like we are burning fat, and perhaps we are, the result of this exercise is a calorie deficit that in turn makes us hungry. We burn more, so the body feels like it needs more, so we tend to eat more.
Exercise doesn’t really burn that much: We often drastically overestimate the amount of calories the body burns through exercise. We often feel guilty about eating pizza or a burger and go for a walk to “burn it off”. But a half hour of running or strenuous exercise burns only about 300 -400 calories. That’s less calories than an average blueberry muffin, and far less than a burger, so while we equated the two to canceling each other out, we actually end up with a net calorie surplus.
We burn less as we exercise more: The first time we do cardio, we burn the most calories. With each consecutive session, our bodies get better at exercise and run more efficiently, and in turn, use less calories to do it. In other words, we get in shape, which is great for our health, but horrible for weight loss. Essentially for exercise 2+2 = 3, as it takes more and more exercise to burn the same amount of calories as we go forward. So you’ll need to do more cardio on day 2 to burn the same amount of calories, while you may bur 350 calories from 30 minutes of cardio on day one, you’ll need 32 minutes to burn 350 calories on day two. This is a big reason why it becomes harder to lose weight as we lose more weight.
Exercising is hard: While jumping on the treadmill one day for 30 minutes is pretty easy. Doing this day in and day out for several weeks is not. It’s much easier to just eat a little less and accomplish the same net effect.
Overall, a combination of healthy eating, portion control and exercise is the best recipe for long term health and a healthy low weight. However, total calorie intake alone is paramount to all in losing weight and maintaining weight loss. Consistent, steady weight loss and diet changes are the way to get and stay lean.