You Can't Burn Calories Fast Enough to Lose Weight

Posted: Dec 02, 2016 6:00 AM
If you’ve been reading my thoughts for awhile—or, really, if you’re just aware of health in general—you know that exercise is extremely important. In fact, for the vast majority of maladies we get, the best preventive medicine we have comes from the benefits of exercise alone! However, exercise is not a total panacea for all that ails us. And, in fact, exercise is given an undue amount of attention when it comes to one issue in particular. I’m talking about
weight. Many people think that exercise is the cure to being overweight. After all, exercise can burn calories, right? Well, I’ve got a sad fact to explain today. While exercise can help you achieve any weight loss goal you might have—both by burning calories during exercise, and upping your metabolism for a couple days afterwards—exercise is really a very small component of a healthy weight loss plan. Much, much more important is diet. In fact, the general rule of thumb is that diet is responsible for about 75% of your weight, while the remaining 25% is exercise, excluding genetics. It’s also much easier to cut calories from your diet than to burn them off later. Indeed, one study found that a group of people who cut calories from their diet lost 23 pounds in 15 weeks; the exercise-only group lost 6 pounds over the same amount of time. In other words, exercise is a component of weight-loss, but a fairly small one. I know that sounds counter-intuitive, and it doesn’t fit into the many myths that surround weight loss. So let me make my point slightly more concrete.

Exercise out versus Calories in

Now, before we begin, it’s important to note that everyone burns calories differently. Your metabolism might be higher or lower—depending on your weight (and how over or under weight you are), muscle mass, and genetic makeup. So, to start out, we’re going to look at the calories burned in an hour by a 160-pound person. Let’s say this person did an hour of hardcore aerobics. That means breathing hard and sweating for one hour, straight—no water breaks, no cool-down or warm-up during the hour—pure active motion for a full hour. That would burn about 533 calories (a 200-pound person would burn almost 25% more calories, so you can adjust for yourself in your head). Not bad, right? Except that’s only the equivalent of 4 ounces of chicken, plus a cup of broccoli and half a cup of beans. Not exactly a huge meal. A McDonald’s chicken sandwich is 535 calories. There goes all that work. Biking for an hour straight would burn 292 calories. That’s one fried egg, two pieces of toast, and half a glass of orange juice. An hour of hatha yoga only burns 183 calories. That’s about the same as you’d get in a can of beer. Even running a full marathon only burns about 2600 calories, give or take. Drink two glasses of wine every night, and you’d have used up your entire caloric deficit in just over a week. Unless you are doing some sort of extremely strenuous physical training every day, a la Michael Phelps getting ready for the Olympics, you just aren’t going to lose weight through exercise alone.

The machines are lying to you

However, the news gets even worse. If you’re exercising at the gym, you’re probably paying attention to the calorie count on your favorite cardio machines. Too bad most of those machines are way off. By as much as 25-30%. Part of the problem is many machines just make assumptions about your weight, which can throw the scale off quite a bit. Another problem is they make assumptions about how you are using a machine. For instance, a treadmill will assume that you aren’t using the handrails—if you do, that greatly decreases the calories you burn. And, on top of that, machine manufacturers want you to feel good about what you’re doing. So they’re almost always going to round (or lie!) up the calorie count, to make the benefit of exercise appear as great as possible.

And you might be lying to yourself

That’s not the end of it. It turns out, when exercising, most people think of calories as a monetary system. The more calories you deposit through exercise, the more you can withdraw though eating. But that doesn’t work when you’re overestimating the number of calories you are burning. And, in studies, exercisers routinely underestimate the number of calories they’re eating—by up to three times the true value. In other words, for every 100 calories you think you’re eating, you may actually be consuming 300 calories. Add in the fact that exercise acts as an appetite stimulant for most people, and you can see why exercise alone simply doesn’t lead to weight loss, for the vast majority of people.

Fill up the right way

Instead, if you have a weight-loss goal, there’s one method that’s been proven to work time and again. And that’s cutting the number of calories you consume. After working with my nutritionist Liliana Partida for years, I’m not a big believer in counting calories. Most people don’t do a great job of estimating calories in and out, and besides, it just isn’t a very sustainable way to live. Instead, I believe in focusing on filling yourself up with the right foods. That means drinking lots of water all the time, which can help decrease hunger. It means dividing your plate up the right way. If you make sure half of everything you put in your mouth is a fruit or vegetable, it’s almost impossible to get into trouble. The filling fiber in fruits and vegetables will have you feeling stuffed long before you can overeat. Especially if you keep proteins like meat to a quarter of your plate, and make sure you avoid enriched or processed grains, and stick with 100% whole grains. In fact, one study found that whole-grains are especially good for a weight-loss plan. In the study, participants who ate whole grains lost more abdominal body fat—the especially dangerous kind—than those who ate refined grains. They also saw a 38% reduction in C-reactive protein (CRP), an indicator of damaging inflammation in the body. Nothing will ever be more effective than exercise and diet combined—for your overall health in general, and for your weight-loss goals in particular. But if you decide to focus on one thing, focus on diet. Eating right takes no more time than eating wrong, and eating nutritious foods is the first key that unlocks everything else.
Exercise is just as important for your health in the long run. But, when it comes to losing weight, putting your faith in exercise alone is likely to do more harm than good. Eat right. All other healthy outcomes will flow from there.