Calorie Intake and Energy Expenditure

The Truth About Calories

We set the record straight on negative calories, low-cal diets, and the best calorie-blasting workout

Energy Expenditure, Explained

The Truth About Calories // pointing to calories on nutrition label © Thinkstock

Image: Thinkstock

Counting calories isn’t rocket science. It’s more like basic physics, or at least the first law of thermodynamics—that energy can be changed from one form to another, but not created or destroyed. Burn the 3,500 calories that make up a pound of body fat, and you’re that much lighter.

Try these delicious and filling 400-calorie snacks for weight loss

Still, if it were that simple, we could stop here, and anyone with a pen, paper, and a calculator could slim down without a struggle. Truth is, if you’re trying to lose weight, the source of your calories matters, as does the type of exercise you combine with a low-cal diet.

“If someone is consuming many calories from fatty, sugary, low-nutrient foods, clearly they won’t be getting all the valuable nutrients they need for their bodies to function optimally,” says Elisa Zied, MS, RD, CDN, author of Nutrition at Your Fingertips. “To sustain weight loss, it’s key to keep activity level up and mix up exercises so you’re using different muscle groups or stimulating your muscles in different ways.”

You’re not alone if you’re feeling a little clueless about calories. While 77 percent of Americans say they are trying to lose or maintain weight, only 19 percent track calories, according to a survey conducted by the International Food Information Council Federation. Only 12 percent can accurately target the number of calories they should consume in a day, while 43 percent have trouble estimating how many calories they burn during everyday activities.

Knowing the facts about energy intake and expenditure can help you pinpoint why the needle on the scale gets stuck. Here, nutritionists set the record straight on five matters of calorie confusion.

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