using your muscles to burn fat

and when eaten they bind with the pain receptors in the mouth and throat that detect heat. Once activated by the chilli these receptors send a message to the brain that the person has just eaten something HOT! The brain responds by raising the heart rate, increasing perspiration and releases endorphins. Raising the metabolism therefore burning fat.

If you did not catch that mourning breakfast, you have to start on lunch and dinner. So now you spend the day looking for berries, nuts, eatable roots, and wild game. Water was a problem too, unless you have one of them caves with running water. (hehehe) Along with hunting for food and water, you had to be careful that you did not become food for the larger creatures roaming around.