Before I went on Whole30 I was sleeping 8 to 10 hours a night (yes, I love my sleep), yet come 2 p.m. I'd hit an energy slump. I'd feel high right after I ate (looking back on it, probably because I was eating so much added sugar) but my energy would significantly fluctuate through the day. During the beginning of Whole30 — specifically the first three days — I really struggled. Again, I was a sugar addict and I think detoxing from that really affected my energy levels. But after that slump, my energy was constant — I really had never felt better. Even when things didn't go the way I wanted, I felt energetic and up for any challenge.
Fruits are not only delicious, but they’re also great for you. That said, fruits (even paleo-approved ones) contain large amounts of fructose which, while much better than HFCS (high-fructose corn syrup), is still sugar. If you’re looking to lose weight on the paleo diet, you’ll want to cut back on your fruit intake and focus more on the vegetables allowed on the paleo diet. However, feel free to have one to three servings of fruit a day. Check out this list of paleo diet fruits and see if you’re not hungry by the end! (We’ll admit, we’re partial to blackberries!)
Exercise is a vital part of the live-by-your-genetic-code equation. Surviving in the Stone Age meant a constant on-the-go lifestyle that probably required 4,000-plus calories a day, according to David L. Katz, MD, director of the Yale University Prevention Research Center. Even most people who hit the gym regularly won't need to eat that many calories, but the principle of using food as fuel to exercise still stands.
Excluding foods. The exclusion of entire categories of commonly eaten foods like whole grains and dairy requires frequent label reading in the supermarket and in restaurants. It may also increase the risk of deficiencies such as calcium, vitamin D, and B vitamins, if these nutrients are not consistently eaten from the allowed foods or a vitamin supplement. For example, there are some nondairy calcium-rich foods that are absorbed well by the body such as collard and turnip greens or canned bone-in sardines and salmon, but you would have to eat five or more servings of these greens and fish bones daily to meet recommended calcium needs. (Note that some greens like spinach that are touted to be calcium-rich also contain oxalates and phytates that bind to calcium so very little is actually absorbed.) One small, short-term intervention study of healthy participants showed a 53% decrease from baseline in calcium intake after following a Paleo diet for three weeks.  Furthermore, the exclusion of whole grains can result in reduced consumption of beneficial nutrients such as fiber and thus may increase one’s risk for diabetes and heart disease.
The NY Times had a blog article on Good News on Saturated Fat which is reporting on Gary Taubes's interpretation of the new report in The New England Journal of Medicine on a two-year diet experiment in Israel. A followup is the post The Fat Fight Goes On where Gary rebuts the arguments against the study. And here's a good interview with Taubes (and includes a good summary): Gary Taubes on Cold Fusion, Good Nutrition and What Makes Bad (and Good) Science.
Two years ago, I dropped 30 pounds (and kept it off) by doing the Whole30 and continuing to eat well in the months that followed. During the 30 days on the program, I lost 11 pounds. And for me, completing it helped me form healthy habits (like reading labels and not smothering everything in cheese), taught me how to cook an arsenal of healthy recipes I actually enjoyed eating and most importantly (and the reason why I do it every January), showed me how incredible my body feels when I'm not pumping it full of sugar and alcohol. These lessons stuck with me well past the 30 days, allowing me to drop an additional 19 pounds by April of that year and finally reach my goal weight.
The plan focuses on unprocessed foods and foods with very minimal, or, better yet, no added ingredients. Whole30 requires dieters to cut out a lot of items, including sugar, dairy and legumes, and then slowly reintroduce these food groups back into their diets after the 30 days. The purpose of the reintroduction phase is to see if any of the foods cut out are the culprit for any health issues.
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.