Labeling foods with calories is "the most straightforward way to assess how much energy you're getting from a food," says Marlene Schwartz
, PhD, director of the Rudd Center for Food Policy and Obesity at the University of Connecticut. But one number doesn't necessarily tell you whether or not a food is nutritious — meaning: Quantity is one factor, but quality
is just as, if not more, important. For example, a high-calorie food (like avocados) could contain important nutrients like fat
, and a low-calorie food (like a small bag of baked potato chips) could contain very few nutrients. "The objective is not to eat as few calories as possible, it's to eat the amount that's appropriate for your body to energize and fuel you," says Diane Vizthum, RD, a registered dietitian at Johns Hopkins Medicine.