Diets are popular among Americans, although most fail at sustaining long term weight loss. They are however big business and some folks are becoming quite wealthy off of them. Of the most popular diets, Google recently reported that the most searched-for eating plan of 2013 was the Paleo Diet (Daily Mail Google Diet Searches 2013). This ranked ahead of the ‘Juice Cleanse Diet’, the ‘Mediterranean Diet’ and the ‘Master Cleanse Diet’. In contrast to its popularity among average Americans, however, U.S. News and World Report recently ranked the Paleo Diet tied for last on its “Best Diets Overall” list for 2014 (CNN Best Diet Rankings). This report was developed through consultation with a panel of health experts from top academic institutions around the country, including nutritionists and specialists in diabetes, heart health, human behavior and weight loss. This panel of experts rated each of 32 diets diet in seven categories, including short- and long-term weight loss, ease of compliance, and safety and nutrition. How could such a popular diet be ranked so low by scientific experts? There seems to be a clear disconnect between the American public’s view on dietary eating patterns and what is recommended by health experts.
Let’s take a closer look at the Paleolithic dietary pattern and explore why it is not recommended by nutrition experts. The premise of this plan is to “consume everyday modern foods that mimic food groups of our pre-agriculture, hunter-gatherer ancestors” (Paleo Diet). This includes lots of meat protein, low carbohydrate, high fiber from fruits and non-starchy vegetables, and moderate to higher fat intake, with a focus on mono- and polyunsaturated fats. This dietary pattern restricts cereal grains, legumes and dairy foods. The purported benefits include decreasing risk of obesity, cardiovascular disease, type 2 diabetes, cancer, autoimmune disease and osteoporosis, among other stated benefits. The Paleo Diet web site states that these diseases were typically very uncommon among our early ancestors, and suggests that mimicking their diets should provide the same benefits to modern humans.
If this is all true, then why don’t the experts agree? First, it’s important to consider that prehistoric humans had shortened life spans (probably less than 35 years). In fact, as recently as the mid-20th century, the average human life span was less than 50 years. Another factor to consider is whether we really know how these early humans died and what diseases they suffered from, or exactly what they ate. Other aspects of the Paleo Diet were however considered negatives by the expert panel that ranked the diets. Their criticisms of this dietary pattern included a lack of scientific evidence that the Paleo Diet promoted weight loss or prevented cardiovascular disease, and its restrictiveness. In fact, most nutrition experts recommend consuming more grains (particularly whole grains), legumes (as an alternative protein source to meat) and low-fat dairy products (which on a population-wide basis are amongst the best sources of calcium and vitamin D). So who will you believe, scientific experts or those selling a product on a popular web site?