In the US, the Food and Drug Administration's suggested caloric intake per day is set at 2,000 calories. While a suggested caloric intake is just an estimate that differs depending on a person's size, amount of physical activity, and overall health, among other things, the 2,000 calorie mark is a reasonable one for many people.
To visualize just what 2,000 calories looks like, Business Insider created a photoseries that shows approximately what and how much food makes up that suggested caloric intake at a few of the biggest fast food chains in the world.
At some chains, the 2,000 calorie mark is somewhat reasonable. At Subway, for example, it's a foot-long sub, a six-inch flatbread, and an oatmeal cookie -- which could make up a person's lunch and dinner, at least. However, 2,000 calories is a surprisingly small amount of food at other chains in the series.