Gradual, little steps will get you there, too.
Not everybody needs to eat paleo and wear inov-8s during their first week of CrossFit. The first year I did CrossFit I did it mainly fueled on Hot Pockets, Lean Cuisine, and Diet Coke. No joke. Was it ideal? Um, no. Did I survive? Yes, and I actually built some strength, too, given that I had never lifted a weight in my life previously. Over time I slowly adjusted my diet from “food industry healthy” to actual healthy. But I didn’t do it overnight. I did it with gradual changes and consistent behavior.