Following the paleo diet can be pricey. Inexpensive and healthy non-meat protein sources like soy and beans are off-limits, and a recent BMJ Open study shows that healthy meats like lean ground beef and boneless, skinless chicken breasts cost an average of 29 cents more per serving compared to less-healthy ones, such as high-fat ground beef and chicken drumsticks. Even switching from peanut butter to paleo-approved almond butter will cost you—it goes for up to $13 a jar.
Why so strict? According to the diet's founders, Melissa and Dallas Hartwig, these are the foods that are most likely to cause inflammation and gut damage. They're also the foods that the founders say destabilize blood sugar levels and lead to cravings. But it's hard to say whether that's true for everyone. In general, limiting sugar and alcohol is always a good idea. But dairy, grains, and legumes? They don't trigger an inflammatory response in everyone, Haas says.
Primal Body-Primal Mind: Beyond the Paleo Diet for Total Health and a Longer Life by Nora Gedgaudas advocates a diet that our paleo ancestors ate. Meat, lots of fat, and seasonal fruits and berries when available. Basically, sugar and starchy carbs are discouraged. You can download a chapter from the author's site. She has a Primal Body, Primal Mind Radio weekly show on Voice of America. It started May 20, 2009, so there are many shows you can listen to. Published June 30, 2011.
Certain food groups (like sugar, grains, dairy and legumes) could be having a negative impact on your health and fitness without you even realizing it. Are your energy levels inconsistent or non-existent? Do you have aches and pains that can’t be explained by over-use or injury? Are you having a hard time losing weight no matter how hard you try? Do you have some sort of condition, like skin issues, digestive ailments, seasonal allergies, or chronic pain, that medication hasn’t helped? These symptoms are often directly related to the foods you eat—even the “healthy” stuff. So how do you know if (and how) these foods are affecting you?
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.
CrossFit is a strength and conditioning program consisting mainly of a mix of aerobic exercise, calisthenics (body weight exercises), and Olympic weightlifting. CrossFit, Inc. describes its strength and conditioning program as "constantly varied functional movements executed at high intensity across broad time and modal domains," with the stated goal of improving fitness, which it defines as "work capacity across broad time and modal domains." Hour-long classes at affiliated gyms, or "boxes", typically include a warm-up, a skill development segment, the high-intensity "workout of the day" (or WOD), and a period of individual or group stretching. Some gyms also often have a strength-focused movement prior to the WOD. Performance on each WOD is often scored and/or ranked to encourage competition and to track individual progress. Some affiliates offer additional classes, such as Olympic weightlifting, which are not centered around a WOD.