Are 0 calorie foods really 0 calories?
                                
                                
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                                    4 min read                                
                            
                                According to FDA regulations, a product can legally be labeled "zero calories" if it contains fewer than 5 calories per serving. So, are 0 calorie foods really 0 calories? The surprising truth is that these products can, and often do, contain trace amounts of energy that can add up.