A study published in the Journal of Food Science found that expectations of product quality, nutritional content and the amount of money consumers were willing to pay increased when consumers saw a product labeled "all-natural" as compared to the same product without the label.

Researchers at Ohio State University used virtual reality technology to simulate a grocery store taste-test of peanut butter. In one condition, consumers were asked by a server to evaluate identical products with only one being labeled all-natural. In the other, the server additionally emphasized the all-natural status of the one sample.

In the first condition, expectations of product quality and nutritional content increased, but not liking or willingness to pay additional for the all-natural product. However, expectations of product quality and nutritional content as well the amount of money subjects were willing to pay increased further when a virtual in-store server identified one of the peanut butters as being made with all-natural ingredients. This result was observed across a diverse group of subjects indicating the broad impact of the all-natural label.

Currently, the U.S. Food and Drug Administration (FDA) has not provided a clear definition of the phrases "natural" or "all natural", despite extensive use in US product marketing. Prior research has indicated that consumers define "natural" primarily by the absence of "undesirable" attributes such as additives and human intervention, as opposed to the presence of specific positive qualities.

"We believe our findings provide sound, evidence-based guidance to the FDA and suggest the term natural be regulated so as to minimize consumer and manufacturer confusion over the term. This will serve to protect Americas consumers and manufacturers by ensuring food labels convey accurate and non-misleading information," lead author of the study Christopher T. Simons, Ph.D., explained.