Well, this is upsetting: A new study shows that the number of calories listed on a nutritional label are probably just a close estimate, not the actual number of calories in the food.
The good news: Usually the number of calories in a food are over-estimated, according to the U.S. Department of Agriculture's Human Nutrition Research Center.
Why the discrepancy? The way you eat a food—mashed, cut, whole, whatever—will influence how the calories are "released" in the stomach.
Also, natural "whole" foods contain fewer calories than "processed" foods. Take a potato, for example: Eating a from-the-garden potato will have fewer calories than a potato that's processed in a plant before it hits your table.
So, are our calorie counting efforts doomed? Not necessarily. I've had a nutritionist tell me to assume that the number of calories I eat a day has a 10 percent margin of error. Plus, you need to eat 3,500 more calories than you burn to gain a pound, so it's unlikely you'll do that if you're counting calories to lose weight.
Bottom line: Calorie counts might not be totally accurate, but don't freak out over it.
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