How many calories are there in human blood?

It can be a little dependent upon our more recent caloric intake, however, because most of our energy from food is from stored fats and sugars, our consumption doesn't affect the calories much.

Human blood has very little calories because the energy isn't needed from blood and our bodies were created so ingeniously that if we are healthy our bodies are designed to divert our calories to the areas within the body that need that energy.

The calorie content of a person's blood will depend on what they last ate about an hour or two before giving the blood.

Well you have to tell us what you ate. lol. Animals don't eat sugar.. So they don't have much fat in their blood. Of course an obese person would have more calories.. It's sort of obvious. Haven't you heard of.. "Let's burn some calories?" And like.. The Biggest Loser? C: