Physical

Hunger
One can survive maximum 7-10 days without eating anything. Having enough food will keep you fit.

Water
Water is more important than food. You must have your own stable water source. Different environments, different water sources.

Vitality
Physical power is Hunger plus Water. If you have no power, you can't use tools. And sleeping at the camp will help you recover quickly.

Health
Keep a balance diet with meat, vegetables and carbohydrate food. Cooking meals can make you health. Stay away from dangerous animals.