Dietitian Explains How Different Types of Foods Affect Health and Weight Gain

If you want to stay healthy and lose weight, it's not just the quantity of calories that matters, but the quality of those calories.zarzamora/Shutterstock

A calorie is a calorie is a calorie, at least from a thermodynamic standpoint. It’s defined as the amount of energy needed to raise the temperature of 1 kilogram of water by 1 degree Celsius (2.2 pounds by 1.8 degrees Fahrenheit).

But when it comes to health and your body’s energy balance, not all calories are equal.