Another downside: If you have had chronic health issues (especially gut related), you may find that reintroduction actually teaches you that you're sensitive to most foods. It turns out peanut butter, gluten, and most dairy are now off limits. That rots!! But I'll live. I feel so, so much better without them, as I learned. And wouldn't you rather know why you feel crappy all the time?

Snacks: Snacks were a problem for me. One of favorite snacks is cheese, but dairy was not allowed in the program. One of the most recommended snacks is nuts, but I can’t have them because I have diverticulosis. My fall back was celery with almond butter. It seem to fill me up while meeting the requirements of the Whole 30 plan but it was pretty boring.
Greg Glassman and Lauren Jenai founded CrossFit, Inc. in 2000.[14][15] The company was conceived a few years earlier, in 1996, as Cross-Fit.[16] The original CrossFit gym is in Santa Cruz, California, and the first affiliated gym was CrossFit North in Seattle, Washington; there were 13 by 2005, and today there are more than 13,000.[6] Coaches associated with CrossFit include Louie Simmons, John Welbourn, Bob Harper, and Mike Burgener.[17]