A Big Mac contains 30 grams of fat. Each gram of fat contains 9 calories. 9 x 30 = 270 calories from fat. Since a Big Mac packs 560 calories total, that means that nearly 50 percent of the calories in it are fat calories. That's 20 percent more than recommended. Some 16 percent come from saturated fat, so that's well over the recommended max, too. (p. 81)Spurlock preforms this kind of breakdown for a number of fastfood items he considers unhealthy.
This is an odd way of going about the USDA dietary recommendations. Note the preceding phrase: dietary recommendations. No one food item will meet all of the USDA's suggestions. They weren't written to be be applied that way. The only way Spurlock's method of criticism would be applicable is if one were to eat a diet of nothing but Big Macs. Most people know better than that.
Save for wry, documentary filmmakers, I guess.