The definition of natural means that it is something that exists or is created in nature rather than made by mankind. Crude oil, for example, is natural; the refined gasoline that we fill up our cars with is not.
In regards to food, consumers tend to think that the word "natural" means that the food is less "artificial" than a conventionally produced item. If you were to ask a group of people to define what "natural" means on a food label, you'll likely get a broad range of answers including no-added hormones, non-GMO, and no "artificial" additives. "Natural," for many people, implies that the food is somehow healthier because it is the opposite of unnatural.
So why would there be such a broad range of answers to a labeling question? Well, it turns out that that there is no right answer.
In the food industry, there is no set definition and no regulations regarding "natural" products. Currently, the FDA only has an advisory that a "natural" product is one free from added color, artificial flavors, or synthetic substances. This is essentially an opinion and lacks the legal binding of a regulation.
The FDA has no set definition because so much of our food has been processed and is no longer a product of the earth. The FDA itself has admitted that it hasn't developed a definition for the term "natural" and its derivatives due to this difficulty.
However, the FDA is currently accepting comments on whether it is appropriate to define "natural" and, if so, how it should be defined and regulated on food labels. The FDA is accepting comments from 11/12/2015 through 02/10/2016 and will use public input to determine how to address "natural" as a regulated label. You can read more regarding this and submit a comment here.
1. Be free of artificial colors, flavors, sweeteners, preservatives, and ingredients that do not naturally occur in the food.
2. Must be minimally processed in a method that does not fundamentally alter the raw product.
3. The label must explain the use of the term "natural," e.g. no artificial ingredients.
So if "natural" is not a federally regulated term outside of meat and poultry, does it mean that companies can simply slap "natural" on any product packaging and get away with it? Not necessarily.
What it boils down to is this: take any claims that a food is natural with a grain of salt. And remember that "natural" potato chips aren't any kinder to your waistline than the normal kind.