I do not recommend a very strict diet. My belief is that we should eat what our bodies enzyme systems can effectively utilize. This means whole foods, not processed foods. If we look at our diets from this perspective, what to eat or not eat becomes a much simpler, intuitively obvious situation. Let me give a few examples.
Many people have difficulties with dairy products.
This is not surprising. We have been eating animal products for tens of thousands of years, but before animal husbandry, a relatively new skill, we did not have the opportunity to accumulate large quantities of milk, much less butter and ice cream. The point is that every individuals enzyme system will be able to handle different quantities of these foods and some of us will have to restrict them quite a bit. Carbohydrates are the class of foods that provide us the energy we need to survive, the energy to breathe, maintain our body temperature and move around. Our bodies have a complex and relatively delicate system to process carbohydrates and maintain the proper blood-glucose levels.