Question: how many joules of energy are in the human body?
Answer: Using a simple conversion (1000 calories = 1 Calorie, 1 calorie = 4.1868 J), this amounts to 8.37 x 106 joules ingested per day. This means that the average person expends ~8.37 x 106 joules of energy per day, since most of us are in some sort of equilibrium with our surroundings.