The first law of Thermodynamics holds that in any situation the total amount of energy with in is equal to the total amount of energy out. This also means that you can't create energy or destroy it. So well what happened to all the energy we have put in our bodies? The long story short, most of the energy is stored in your body, and on average a human carries around 7*10^18 joules of energy on average. If all that energy were to release all at once, it would have the same effect as setting OFF 30 HYDROGEN BONDS AT THE SAME TIME!!!!!