Plus mono diets like eating only rice or potato are effective at loosing weight. What processed food brought is very unnatural combination of a lot of refined

Plus mono diets like eating only rice or potato are effective at loosing weight. What processed food brought is very unnatural combination of a lot of refined carbohydrates and a lot of fat especially in the form of polyunsaturated seed oils. Seed oil consumption in substantial quantities is relatively new thing (like 100 years). And even olive oil (with its rather low polyunsaturated fat content) was never staple food. In Ancient Greek literature, for example, there are more references to its usage as cosmetic or for lighting than for eating.