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.
Trying to devise an ideal diet by studying contemporary hunter-gatherers is difficult because of the great disparities that exist; for example, the animal-derived calorie percentage ranges from 25% for the Gwi people of southern Africa to 99% for the Alaskan Nunamiut. Descendants of populations with different diets have different genetic adaptations to those diets, such as the ability to digest sugars from starchy foods. Modern hunter-gatherers tend to exercise considerably more than modern office workers, protecting them from heart disease and diabetes, though highly processed modern foods also contribute to diabetes when those populations move into cities.
The Paleo diet includes nutrient-dense whole fresh foods and encourages participants to steer away from highly processed foods containing added salt, sugar, and unhealthy fats. However, the omission of whole grains, dairy, and legumes could lead to suboptimal intake of important nutrients. The restrictive nature of the diet may also make it difficult for people to adhere to such a diet in the long run. More high-quality studies including randomized controlled trials with follow-up of greater than one year that compare the Paleo diet with other weight-reducing diets are needed to show a direct health benefit of the Paleo diet. Strong recommendations for the Paleo diet for weight loss cannot be made at this time.
Food and Western Disease: Health and nutrition from an evolutionary perspective by Staffan Lindeberg (MD at Lund University in Sweden) is the newest book promoting the paleo diet. It covers the link between diet and disease in the Western world (all major diseases, including cancer, heart disease, obesity, stroke and dementia) and towards a greater knowledge of what can be defined as the optimal human diet. Benefits and risks are detailed. The Amazon reviews are all 5 stars. Especially read Susan Schenck's detailed review. You can read a preview at Google Books
Meetup has a growing number of paleo groups, now numbering in the dozens. Each has a local message board. They have a map of Paleo Diet Meetups around the world. Initially I tried listing them all here. The number grew and Meetup wasn't letting me find groups in newest order, except for my zip code. You now have to go there to find the one nearest you.
Plus, I feel like the way I eat directly affects my mood. If I eat sugar, I almost always feel like garbage. If I eat protein and veggies and tons of avocado, I feel stable and much less like I am going to have a stage-four meltdown. Blood sugar swings are also real — no one wants to deal with me when I am hangry. It’s a nightmare. This program is supposed to help with all these things. I desperately wanted to feel better, so I dove in.
Overall, the diet is high in protein, moderate in fat (mainly from unsaturated fats), low-moderate in carbohydrate (specifically restricting high glycemic index carbohydrates), high in fiber, and low in sodium and refined sugars.  The monounsaturated and polyunsaturated fats (including the omega-3 fats EPA and DHA) come from marine fish, avocado, olive oil, and nuts and seeds.
CrossFit is promoted as both a physical exercise philosophy and a competitive fitness sport, incorporating elements from high-intensity interval training, Olympic weightlifting, plyometrics, powerlifting, gymnastics, girevoy sport, calisthenics, strongman, and other exercises. It is practiced by members of over 13,000 affiliated gyms, roughly half of which are located in the United States, and by individuals who complete daily workouts (otherwise known as "WODs" or "workouts of the day"). CrossFit has been criticized for allegedly causing people to suffer from unnecessary injuries and exertional rhabdomyolysis.