What is the fine-grained topic of the following text: His efforts have directly led to sweeping changes in the supply chains of hundreds of major food companies, impacted countless individuals’ diets, and have been covered extensively by the media: his work has been featured by CNN, in the pages of the New York Times, the Wall Street Journal, the Boston Globe, and countless more; his writing’s appeared in USA Today, the Washington Post, Barron’s and others; his photographs have been featured in the Rolling Stone and Food & Wine; he’s been as a guest on national television news programs; and he was even once a guest on NPR’s Wait Wait...Don’t Tell Me. Only return the topic.
The impact and recognition of a person's efforts in changing food supply chains.