(originally posted 12/4/2013. libbysfitnutrition.com)
With the rise in popularity of cross-fit, “Paleo” or “Caveman” diets have become a cult following as much as the WOD. But is this type of diet really helping your workout or weight loss efforts? Before I get into the discussion, I will say I do eat meat and animal products. Now, let’s take a deeper look into how people have evolved eating, and the pros and cons of a high-protein, low-carb diet.
Hunter-Gatherers have been studied by anthropologists, scientists, and many other research groups, covering all areas of the globe through human civilization. For the great majority, gathering vegetable foods and starches made up the majority of our ancestor’s intake globally, with hunting being merely opportunistic. Animal consumption made up a larger portion of the diet in the highest longitudes, with most groups of people relying on a heavily plant-based diet.
When our ancestors did get an animal, it was wildly different than today’s meat stock. Wild game is much leaner than even the grass-fed and free-range animal products in stores today. Even hunting wild game yourself in North America doesn’t have the same nutrition profile as it did thousands of years ago. Now, the human gut evolves along with the diet over time to be able to eat food as the food evolves. Much of today’s foods are in a more “pre-digested” form, which is easier on our gastrointestinal tract than foods from the hunter-gathers era.
Another difference from our ancestors is activity. The hunter-gatherers were physically active most of the day (>8 hrs) walking, pulling, cooking, carrying heavy things, etc. Most people today do their hour or two-hour workout a few times a week, and think that that is plenty of exercise. The difference in levels of activity can equal thousands of calories, and differing nutrient needs.
So what does the Paleo diet get right? Cutting out refined grains and sugars not naturally occurring in vegetables and fruits (not sugar cane) is a fantastic thing to do for your diet! Processed white flour lacks essential nutrients found in whole foods. Another thing Paleo does well is to encourage eating vegetables, any kind of vegetables. Eat the rainbow! Also, no eating hydrogenated oils (these are the “trans fats” found in processed foods and processed oils).
The downside of Paleo is its risk to your heart and overall health. Paleo encourages high saturated fat consumption (we are supposed to eat less than 10mg/day according to the 2010 Dietary guidelines) from meat and butter and heavy cream; yet eschews all other dairy. Now you can get enough Calcium and Vitamin D from green leafy vegetables, but most Americans do not eat enough of these to meet their needs. Fruits and nuts are limited, which is helpful in weight loss, but if taken too far can lead to nutrient deficiencies. It leaves out all cereal grains and legumes, which contain essential nutrients, filling fiber, and are the main diet components of many countries (such as Japan) where people are lean and healthy. With all these missing nutrients it is no wonder they tell you to supplement many vitamins and minerals that you could get through a balanced diet that does not cut out food groups.
For healthy individuals wanting to slim down before an event, using this diet for about 2 weeks can have a slimming effect. That being said, I would not recommend this diet for long–term use (greater than a few weeks), or for people with co-morbidities such as heart conditions, cancer, and eating disorders. As with other high-protein diets (ie: Atkin’s) the risk of heart disease is great, and initial weight loss is water that will quickly be regained upon cessation of the diet.
Don't just take my word for it:
Ted-Talk: Christina Warinner, anthropology expert, "Debunking the Paleo Diet"
Milton, K. Hunter-Gatherer Diets – A Different Perspective. Am J Clin Nutr. March 2000 vol. 71 no. 3 665-667.
Paleo 101. <http://paleodietlifestyle.com/paleo-101/>
Libby is a Registered Dietitian focusing on eating disorder treatment and prevention. She is working on the central coast to create wellness in individuals and the community
Not Your Average Nutritionist, LLC