People often follow rigid diets that are full of rules. Most diets come and go. Despite their claims, diet is not one size fits all. Most diets do not — cannot — account for differences in one’s genes, state of health, or nutritional needs. Schedules, budgets, or food availability. Personal preferences or even cultural traditions. But diet — the word — just means which foods we eat regularly to obtain nutrients. So, don’t think of it as “following a diet” but rather a way of getting all your nutrients through your diet. The purpose of diet is to choose foods to regularly eat that will provide you with needed nutrients.
from the Eat Chapter, The Simple Seven