You must pack food that has high concentrations of fat and protein. Food like granola bars and canned meat are a good source of energy and heat. This is because the body breaks this food down easily converting it into usable energy. Though some people would suggest that you pack food that are high in carbohydrates, fats and proteins are long-term sources of energy that you would need for your hiking trip.
In my opinion mixed layers would be the best choice
