What led me to paleo eating was the discovery of scientific studies that demonstrated the nutritional superiority of the diet. These studies pointed out the benefits of introducing lean meats and fish back into my diet while clearly explaining how grains, gluten, and the processed carbohydrates (breads, cereals, pasta etc.) that I regularly consumed were affecting my health.
After reading a ton of material on the subject I was convinced to give it a shot. I'm now feeling better than I have in years and working to become a stronger communicator of a lifestyle that I feel has the potential to make a huge dent in the healthcare epidemic that we're currently facing.
The following is my attempt to answer three of the major major "why's" that I've encountered while providing a link to published research for those wanting to dig a little deeper.
Why Low Carb? Because it regulates insulin production.
Carbohydrates control insulin production. Insulin controls fat storage.
This oversimplified equation is possibly the most important piece of nutritional information to explore regarding body composition and weight management: two factors that unfortunately define many peoples relationship to food.
(We should be clear to separate processed carbohydrates from those naturally found in fruits and veggies while focusing on the glycemic load of the food itself, i.e. to what extent it cause's blood sugar levels to spike and then rapidly fall)
Endurance athletes or anyone doing glycolyticaly demanding workouts such as CrossFit or other high intensity strength and conditioning circuits need significantly more carbs to both fuel and recover from these efforts. Good carb sources for athletes can be found in root vegetables such as sweet potatoes and yams which won't spike blood sugar as much as carb-rich fruits leaving you feeling good both during and following your long workout.
Why No Grains? Because of phytic acid.
All whole grains contain the anti-nutrient phytate, or phytic acid, which binds the key minerals that they are noted for providing (e.g. magnesium, calcium, iron, zinc) making them unavailable for absorption in our bodies. Studies have also shown that whole grains impair our metabolism of Vitamin D, a hormone that many of us are deficient in to begin with and one that is critical to the function of so many of our cells and organs.
By following USDA guidelines grains can make up nearly a quarter of our daily calories which can be better obtained from nutrient dense sources such as lean meats and fresh vegetables.
Why No Gluten? Because you might be allergic to it.
The number of Americans who have been diagnosed with celiac disease, an autoimmune disease triggered by the consumption of gluten proteins found in wheat, rye, and barley has risen to the point that the Center for Disease Control now considers gluten-sensitivity to be a major public health risk. With symptoms ranging from anemia, to type 1 diabetes, to infertility there is a high risk of living with celiac without ever being diagnosed.
The best approach that I've heard regarding the identification of gluten sensitivity/intolerance comes from Paleo pioneer Robb Wolff and can be applied to any dietary or lifestyle change that you might want to try out.
"Cut it out for 30 days and see how you look, feel, and perform. Measure the bio-markers of health, wellness, and disease (total cholestorol, blood pressure, vitamin d levels, cortisol levels etc.) Now reintroduce it and see how you look, feel, and perform. Measure the bio-markers of health, wellness, and disease. See how you do..."
The following is a link to peer-reviewed papers by Professor Loren Cordain, Dr. Boyd Eaton, and other experts on Paleolithic nutrition http://thepaleodiet.com/published-research