Fundamentally, almost all foodstuffs are derived from natural products...
The Real Natural Dog Food
The word “natural” is arguably the most overused word in food advertising and has lost its meaning. Truly natural dog foods are at the very minimum grown under organic guidelines. What is the point of making a food from ingredients that have cancer‐preventing qualities, if they have been sprayed with pesticides or processed with chemicals and other nasties?
If a product is not organic it cannot be considered as the real natural.
"Natural foods" and "all natural foods" are widely used terms in food labelling and marketing with a variety of definitions, some of which are vague. The term is assumed to imply foods that are minimally processed and do not contain manufactured ingredients, but the lack of standards in some jurisdictions means that the term assures nothing. The term "organic" has similar implications and has an established legal definition in many countries and an international standard.
"Natural foods" are often assumed to be foods that are minimally processed and do not contain any hormones, antibiotics, sweeteners, food colours, or flavourings that were not originally in the food. The terms are often misused on labels and in advertisements.
The international Food and Agriculture Organization's Codex Alimentarius does not recognise the term "natural" but does have a standard for organic foods.
Fundamentally, almost all foodstuffs are derived from the natural products of plants and animals and therefore any definition of natural food results in an arbitrary exclusion or inclusion of food ingredients; likewise, since almost all foods are processed in some way, either mechanically, chemically, or by temperature, it is difficult to define which types of food processing is natural.