If you burn 500 calories exercising can you eat 500 calories without gaining weight?

Answer 1

Not necessarily. A certain amount of the energy that you're going to be burning in the gym is going to be sugar based, readily available energy that wouldn't have translated into weight, anyway, because your body would have excreted it if unused. Not all energy is stored in the body after digestion, and certain forms of energy or foods will alter how efficiently you process energy-dense material (sugar, fat, and protein.)

Weight gain is not the only problem. There are problems associated with intake of certain sources of energy that the casual dieter doesn't usually understand. Certain fats are necessary in small quantities, but certain fatty foods have compounds such as HDL cholesterol which can build plaque in your arteries, and foods with lots of simple sugars can make your blood sugar spike dramatically.

To address your question, however, if you were to eat ONLY 500 calories in a day, and burn 500 calories at the gym that same day, then you would not gain weight. In fact, you would likely lose some (if you'd already depleted your free energy reserves) because your body is going to be using more than those 500 calories to do other things, such as walk, and breathe. You aren't going to be eating ONLY 500 calories in a day, however, because your body needs vitamins, minerals, protein, and certain amounts of oils in order to keep in top form. (Also, you can get 500 calories from six tablespoons of peanut butter, and that would not be very filling. As you can see, the form in which you eat these calories is going to matter. You don't want to be starving all day.)

Also, to put things in perspective, burning 500 calories at the gym is going to be a rather long and difficult process. To quote nutristrategy.com, if you were 155 lbs, and ran at five miles per hour FOR AN HOUR, you would only burn 563 calories.

The final answer, then, is "kind of yes," but remember that this only applies if you're ONLY eating a small amount of food in a day, and that's dangerous for reasons that far outweigh the social risk of slight chubbiness.