In order to survive, your body needs enough nutritious food to maintain body weight and supply you with energy you will need in emergency situations.  Stress can cause you to burn more calories than normal.  Emergency situations present other  problems, such as storage and cooking food which will keep you healthy.

Most disaster situations are easily prepared for by stocking up on MRE's But long term survival will depend on adequate food supply, renewable foods such as those obtained by planting your own survival food garden. During the time it takes to harvest your garden, freeze-dried and dehydrated foods will ensure you have enough food for several months to a year.