Some variation from the official count should be expected, depending on how your food is prepared. Here's what companies said about these discrepancies:
McDonald's did not respond to a request for comment.
Chipotle: "Our food is prepared in our restaurants and assembled to order by the people who work there (not by machine as you would have in a packaged food production facility), so there is always the possibility of some variation in calories, tough we work hard to be sure portions are consistent and correct."
KFC (Yum! Brands): "We send a composite sample of our products to an outside third part for nutritional analysis, which includes caloric content."
Starbucks: "We calculate the nutritional information based on standard recipes, and use best-in-class resources such as USDA guidelines for commodities like milk and our suppliers' nutritional information for ingredients such as sauces and syrups."