By Brian Wallace, Ph.D., FACSM, CSCS |
The Paleo or ‘Stone Age’ diet has become exceedingly popular especially in health circles and among fitness enthusiasts. In fact, it seems to be a nutritional strategy that continues to evolve. The name ‘Paleo’ does have considerable cachet and its own evolution has brought it to the forefront of the health, fitness and athletic arenas – encompassing more than just a diet but a health and fitness lifestyle as well – which all of us in the exercise, sport and nutrition fields know are inextricably connected for success. So let’s take an objective look at this nutritional phenomenon.
The Paleo diet was actually initiated back in the 1970s by a gastroenterologist, Walter Voegtlin, who suggested that eating like our Paleolithic predecessors would make us healthier. Of course, the fundamental hypothesis is a bit questionable – that there was a single and identifiable nutrition strategy used by our Paleolithic ancestors. It seems more likely that food selections were largely directed by opportunity – seasonal, geographical, availability – the latter being the deciding factor.
Leaving evolutionary and nutritional assumptions aside, many prefer to think as the modern Paleo plan as a lifestyle – exercise and nutrition program – as push back on the culture we have created; not just the unprecedented levels of inactivity but also such recent developments as fast food restaurants, supersizing, sugar laden sodas, and all you can eat buffets. We have fallen prey to our own evolutionary success, having created calorie dense foods (loaded with fat, sugar, sodium and an array of chemicals) while minimizing the amount of energy used through physical activity – an expansion of a survival mechanism passed on from our progenitors – conserving energy: maximizing ‘calories in’ from our food while minimizing ‘calories out’ from physical activity. In many ways, obesity, diabetes, heart disease and other common maladies today are the product of a survival strategy initiated millions of years ago.
So how does our modern version of the Paleo diet equate to what our ancestors consumed and is that really the goal? Despite the Stone Age implications, the Paleo nutritional tenets are not in fact written in stone and seem to vary depending on who you are talking to. To be sure, the Paleolithic nutritional assumptions inherent in the diet have stimulated considerable debate which has led to varying interpretations of what foods should and should not be included. It is this consensus discord that makes assessing the nutrient density, biochemical impact and health-fitness effectiveness of the Paleo diet more challenging.
Modern Paleo proponents typically recommend: the primary sources of protein and fat – meats (preferably pasture raised and grass-fed beef and bison), free range poultry and eggs (chicken, turkey, duck) – all antibiotic and hormone free, wild caught fish and shellfish, uncured cuts of free-range pork and organ meats like liver. It also typically includes: naturally grown plant foods, fresh fruits and vegetables, roots and tubers, nuts and seeds: rich in protein and healthy fats and healthy oils including olive oil, avocado, coconut, walnut, macadamia and flaxseed oils. Preferably all organic and locally grown. As most good nutrition plans though, Paleo is as much about what you should avoid: processed foods, sugar, sugar alcohols, pesticides, hormones, antibiotics, grain fed beef and chicken, refined vegetable oils, oils derived from grains and legumes, trans fats, sweets, desserts. In particular, any foods that drive up blood sugars, insulin and inflammation while loading up on calories such as fast foods with supersizing, high sugary sodas, and processed foods – all should be avoided or at least limited in the diet because they are typically high in energy density and low in nutrient density and produce reactive oxygen species (ROS), inflammation, etc.
Proponents also recommend (and this is where the debates get more intense) staying away from grains, potatoes, legumes and dairy. While that may be true for some, it is not true for all and can result in their own problems and deficiencies. Ultimately, a decided limitation with any singular diet strategy is the one size fits all mentality which quite simply is an oversimplification of complex individual physiologic and biochemical dynamics which are in constant flux, varying relative to genetics and lifestyle and changing over time as we age. The Paleo diet could be a good starting point, but to truly be effective your nutrition and exercise program must fit your specific individual physiology, biochemistry and lifestyle so monitor your responses and modify your plan accordingly. I’m sure Paleo man would’ve felt the same! See related articles in the Sport Digest: Physiologic Individuality; Ketogenics – a Case Study; and the Living Lab: Mapping your Physiology.
Dr. Brian Wallace is the chair of sports exercise science at the United States Sports Academy.