When Jared Fogle attended an assembly at Northview Middle School, he mentions that he lost weight on the Subway diet. Subway's meals have just as much calories and fat as McDonalds. Subway's nutritional labels show that just about every sub sandwich including the meal has hundreds and hundreds of calories. There is no way to lose weight while on a fast food diet. Morgan himself proved it to be a fact.
Although a calorie is the amount of heat required to raise the temperature of 1 gram of water by 1 degree Celsius, a food Calorie is actually a kilocalorie (aka "kilogram calorie" or "large calorie"), so the nutrition expert's definition is correct in this context.
When the movie shows McDonald's locations worldwide, 2 golden arches were shown in the country of Iceland. However, many people know Iceland to be a country with no McDonald's restaurants. The film, however, was released in 2004 and McDonald's didn't close its Reykjavic restaurants until 2009. So it was correct at the time.