Yes and no.

There is a "calorie" and then there is a "Calorie".

1 Calorie = 1000 calories = 1 kcal

Both are measures of energy. A calorie (also known as a "small calorie") is the energy needed to raise the temperature of 1 gram of water by 1 °C (as a specific temperature and pressure, and several different definitions have existed). Today, the standardized definition is that 1 calorie is exactly equal to 4.184 joules.

This is a small amount of energy compared to the energy content of food, so a second definition of the calorie (also known as a "large calorie" or as a "dietary calorie") arose which is the energy needed to raise the temperature of 1 kilogram of water by 1 °C. This is technically one thousand small calories, or 1 kcal. To distinguish the two when we just want to use the word "calorie", the large calorie is capitalized while the small calories isn't. That's fine when you are writing or reading something -- even then there can be confusion because maybe it is capitalized due to grammar rules and not because it is a large calorie -- but gets lost when something is being spoken. That's why I use kcal or kilocalorie as my preferred way of expressing it.

To give an idea of how much energy living things consume, the energy released by a standard "stick of dynamite" is 1 MJ (one million joules). This is 239 kcal. A normal Hershey's chocolate bar is 220 kcal, so eating a candy bar is consuming the energy equivalent of a stick of dynamite. If you expend 2400 kcal a day, then you are expending, on a daily basis, the equivalent of ten sticks of dynamite.

To take that even further, a pound of fat has roughly 3500 kcal of energy stored in it, which is equivalent to nearly 15 sticks of dynamite or nearly eight pounds of TNT (7.7 lb). If someone is 200 lb overweight (we'll assume that all of that weight is excess fat at 3500 kcal/lb), then the energy in their excess fat is 2.9 GJ (nearly three billion joules of energy) and is equivalent to the energy of 0.7 metric tons of TNT, which is about 1500 lb of this high explosive, which is a 3/4 ton pickup truck loaded to capacity. It is also approaching the scale of the smallest nuclear explosives ever developed (intended for civil engineering demolition work).

Mother nature is very good at packing lots of energy into small spaces, but it is hard to release that energy very quickly. Man, on the other hand, has a hard time packing any where near the same energy into the same small space, but is very good at putting it into a form that can be released very quickly.