The key aspect to the clean food movement is eating foods that are as close to their natural state and point of origin as possible. The movement also adopts “slow foods” lifestyle – foods that are grown, prepared and eaten without the fast food rush. For example, instead of purchasing prepared chicken nuggets from a fast food restaurant or a grocery store, they would cook their own chicken.

Clean foods are free of artificial preservatives, ripening agents, growth hormones, synthetic pesticides, and artificial coloring. Clean foods also should be in season and transported from a reasonable enough distance for it to retain maximum nutritional value. Clean foods are not only fruits and vegetables, but they also include meats that are humanely prepared and seafood that are not overfished.

References:

http://www.usatoday.com/news/health/story/2012-07-24/clean-eating/56456224/1

http://www.huffingtonpost.com/susan-weissman/what-is-clean-food_b_446035.html