By Roberta H. Anding, MS, Baylor College of Medicine and Texas Children’s Hospital
Edited by Kate Findley and proofread by Angela Shoemaker, Wondrium Daily
Do you reward yourself after a workout with your favorite sugary or salty treat? Professor Anding explains why this is counterproductive and why you’re probably not as active as you think.
Out-Eating Exercise
Many people are disappointed to find that they’re still not losing weight after beginning an exercise regimen. Sometimes they even gain weight because they overestimate how many calories they’re burning. When it comes to caloric balance, most people out-eat their exercise, meaning they consume more calories than they burn through exercise.
“I live in Houston, where it’s unbelievably hot and humid, and so people believe that if they sweat, somehow they burn significantly more calories than if they haven’t,” Professor Anding said. “I can walk outside in Houston and start sweating within the first five minutes that I’m out the door, with no real activity.”
There are many methods for estimating calories expended in exercise, but in general, you burn 100 calories per mile, or 100 calories per 2,000 steps. If you walk three miles, you burn around 300 calories. If you eat a large chocolate chip cookie afterwards, that’s 450 calories. You out-ate your exercise.
If you are trying to manage your weight, you shouldn’t account for the amount of calories you’re burning during average physical activity. This is because many of us overestimate the amount of calories we burn, using factors that actually have little bearing on energy expenditure, as demonstrated by the example about sweating.
At the same time, we underestimate the amount of calories consumed each day. All those chocolates and handfuls of chips add up. Even an extra serving of rice can outpace the calories burned during a jog.
Determining Caloric Needs
Most public health agencies recommend that you take 10,000 steps per day. There are about 2,000 steps per mile, so in a 10,000 step day, you might have burned an additional 500 calories. Because most of us have sedentary lifestyles, when we walk or exercise, we really overestimate the value of that.
Exercise and movement can be quantified by adding about 30 percent to your basal metabolic rate (BMR)—calories burned at rest—if you are sedentary. Sedentary means that other than activities of daily living, you’re not engaging in any purposeful exercise such as running or walking.
For example, if you’re 5 foot 4 inches, you can calculate your ideal body weight using the Hamwi equation, which would come out to 120 pounds. Your basal energy needs are 1,200 calories (found by multiplying your ideal body weight times 10), so you can add about 30 percent to that, bringing your average caloric need to between 1,500 and 1,600 calories. That is not a lot of food in today’s environment of large portion sizes and on-the-go processed food.
How Active Are You?
If you’re unbelievably active, meaning you have a physically active job, such as a waitress or construction worker, you do yard work, and you also do purposeful exercise, you could double your BMR calories to 2,400. Very few Americans fall into this category.
Most of us fall in the middle, with people who are moderately active. You may have a desk job, but you go out and get regular activity. You may like to read during the day or work around your home, but you’re still getting some exercise.
In this case, you add about 50 percent to your basal energy needs. Again, if your BMR is 1,200 calories, adding 50 percent means that you get about 1,800 calories.
Therefore, caloric needs can be adjusted to your level of physical activity, but it is important not to overestimate how many calories you are burning through exercise. Unless you are a competitive athlete or have a physically demanding job, most likely you are not burning enough calories to eat that slice of cheesecake every day and still meet your weight loss goals.
This article was edited by Kate Findley, Writer for Wondrium Daily, and proofread by Angela Shoemaker, Proofreader and Copy Editor for Wondrium Daily.
Professor Roberta H. Anding is a registered dietitian and Director of Sports Nutrition and a clinical dietitian at Baylor College of Medicine and Texas Children’s Hospital. She also teaches and lectures in the Baylor College of Medicine’s Department of Pediatrics, Section of Adolescent Medicine and Sports Medicine, and in the Department of Kinesiology at Rice University.
