Its recommendations will often be different for each person regarding which foods and which lifestyle they should follow in order to be completely healthy. This is due to it's use of a constitutional model.
Everything in Ayurveda is validated by observation, inquiry, direct examination and knowledge derived from the ancient texts.
It understands that there are energetic forces that influence nature and human beings. These forces are called the Tridoshas
Because Ayurveda sees a strong connection between the mind, body and soul, a huge amount of information is available regarding this relationship.
Each person has all three Doshas, but usually one or two dominate. Various Dosha proportions determine one's physiological and personality traits, as well as general likes and dislikes. For example Vata types will prefer hot weather to cold and Kapha types are more likely to crave spicy foods than other types.