We have to eat the food which was consumed by our ancestor (Father, Mother, Grandfather, Grand Mother and still more we have to look back). Because we are inherited from our ancestor. Our are just the extension or projection of their chromosomes. Our body cells will live healthy and becomes energetic only when we eat what our previous generation eat to build their body and livelihood. This is the only way to best survival. If we try violating this our genetic pattern will get altered body prone to have disorders and diseases.
For the best survival knowing our family history is more important. Thats why in Hinduism we celebrate death anniversary. On that day we pray with all the food items which they mostly like and we peak about their lifestyle by remembering them.