An Appeal to Nature is the assumption that something that is “Natural” is inherently better than something that is “Unnatural.”
This fallacy is not to be confused with “The Naturalistic Fallacy” which is a card for another day.
First off, “natural” is a loaded term(a link to that card is coming soon!), meaning it brings on certain feelings when it is used. In actuality the word is vague and thus not super useful when describing things.
Mostly this fallacy is used in the selling of products deemed to be better for you because of their ‘naturalness’. Certain industrial processes can indeed take away nutritional value from your food, but since the term ‘natural’ doesn’t have a specific definition(nor regulation on its use), including it in marketing only helps in conjuring positive images, as apposed to relaying any real information about a product.
The term is vague because there is no clear destination between natural and unnatural. Is heating food natural? Farming? Fermenting? Cross-breeding plants?
It is also fair to question feelings the term ‘natural’ brings. Here is a list of ‘natural’ things that will kill you soon as look at you: snakes, hemlock, flesh-eating bacteria, allergic reactions, and bears. Although if you ate bear you’d probably be okay. There are also loads of man-made ‘unnatural’ things/processes that have improved, extended and saved countless lives such as vaccines, indoor plumbing, and agriculture.
While there are certainly arguments to be made when considering the source, contents, and processing of food/other products, anything using the term”natural” is probably worthy of a raised eyebrow.