These are trends or at most guidelines under certain circumstances. They are conceived in relation to a Western diet. It may not be possible to meet the requirements of these guidelines (and to extremes may be inappropriate). They are not rules, and are, at most, guidelines. They indicate a direction rather than a practice. They indicate a preference.
Where there is a serious and immediate threat to health and well being then different rules may be applicable. For example where infectious diseases are common, canned food may be preferable to fresh food. It is preferable, then, to drink tea rather than water, because tea destroys some infectious agents.
Quite obviously, where food is in short supply, any food is better than no food (or dying of starvation or thirst)..This obvious statement is made because sometimes people forget, especially when considering third world countries.
Do remember the following point. The effect of eating certain foods in a certain way is likely to have a long term rather than a short term effect. So occasional breaches of the guidelines, for example, pleasing grandma by eating her cookies, is preferable to developing a superior attitude. Eating undesirable food occasionally is not likely to affect someone whose diet is otherwise good. It may be better to eat the occasional chocolate bar rather than to stuff yourself with rice!
In addition, following these guidelines to an extreme will not guarantee greater health and wellbeing than following them in principle. There is no value in being an extremist.
Nonetheless, these guidelines give an idea towards good health and wellbeing.
Foods and beverages that have a long history in our evolutionary development are preferable to recently added foods and beverages. Leafy vegetables, fruit and meat should form the staple diet. Leafy vegetables and fruit should be eaten much more frequently and in much larger quantities than they are currently consumed in the West.
Leafy vegetables and fruit are preferable to cereals.
Meat is preferable to milk.
Game and fish are preferable to domesticated animals.
Foods or beverages that do not have a long history in our evolution, are preferably eaten or drunk less frequently than foods with a long history.
Fresh products are preferable to other products.
Natural products are preferable to processed products.
Whole products are preferable to parts.
Whole rice is preferable to polished rice.
Fat in vegetables and meat is preferable to added, refined fats.
A diet that contains a variety of foods is preferable to one that contains a limited selection.
The way a food or drink is prepared, affects its nutrient content and its anti-nutrient content.
Clean, wholesome and fresh uncooked food and unheated beverages are preferable to those that have been cooked or heated.
Food cooked at a lower temperature (stews) is better than food cooked at a high temperature (roasted, fried).
Vegetables sliced along their natural meridians are better than vegetables sliced otherwise, or food that is mashed.
Foods are better eaten with other foods that they are naturally found with that food
Vitamin supplements are preferably taken with natural sources of these vitamins.
Fish may preferably be eaten with water cress.