A Diet is a regulated combination of foods designed for medical or nutritional reasons. A diet should include a balanced selection of foods vital for good health, taking into account the individual's specific dietary needs. A special diet is prescribed for each individual depending on his (or her) age and medical condition like obesity or sensitivity to certain foods.
A diet should preferably contain all the essential nutrients, like protein, carbohydrates, fibers, minerals, vitamins, etc. to make it a healthy diet. You should incorporate the ingredients for healthy recipes to ensure a healthy diet. In special conditions like a pregnant woment or an infant or a senior person, the requirement are different. Therefore the same diet is not good for all.