It is True... 

There are actually calories in items listed as ZERO!  But before you go trashing your little yellow packets and picketing PAM, here's the deal. According to FDA rules, if something has less than FIVE calories per serving, the label can claim it has ZERO calories. Most "zero-calorie" sweetener packets have about 4 calories each, however that's still less than a third of the calories in sugar packets. Things get a little trickier with nonstick spray. While a serving has less than 5 calories, a typical serving size is listed as "a 1/4-second spray." Is it even possible to spray for less than a second? Highly doubtful. A much more realistic serving is a 1-second spray, which has about 5 to 10 calories and 0.5 to 1 gram of fat. Still MUCH better than even a teaspoon of cooking oil, which has about 40 calories and 4.5g fat. So use these low-calorie staples, but be aware that they do contain some calories. If you're a strict calorie counter who uses many "zero-calorie" sweetener packets per day, start counting those 4 calories per packet. If you're going through that can of cooking spray pretty quickly, keep in mind that the average can contains around 900 calories. No reason to be alarmed here, but this is good info to know and understand. Knowledge is power!