If you have been listening lately, you have probably heard the Paleo Diet sales pitch. And to be sure, many of the Paleo Diet websites you visit will be happy to sell you something. Here are some examples, where you can also get a summary of the plan; http://www.paleoplan.com/, http://thepaleodiet.com/. There are some very healthy aspects to the Paleo Eating Plan. The focus on fruits, vegetables, nuts, seeds and healthy oils over processed foods and sugar is consistent with most other respected healthy eating plans. This plan can work for weight loss since you are eliminating entire groups of food (grains and legumes). These foods are replaced, at least in part, by less calorie dense foods (fruits and vegetables), which should result in overall reduction of calories. However, basing a diet on a guess of what our ancestors ate raises some important questions.
Do we know what our ancestors ate?
Most adherents to the Paleo Diet will authoritatively claim that our ancestors ate mostly meat, or a great deal of meat. While this may be commonly accepted amongst Paleos or even other lay people, you will not find the same agreement amongst anthropologists. The truth is that we really don’t know what our ancestors ate. There is conflicting research regarding the amount of protein in their diet. More importantly, what they ate probably depended on where they lived. Paleolithic people who lived on the Savannahs in Africa, where the majority of early humans lived, ate quite differently than those who lived in arctic areas. This is important evidence that we have evolved to take advantage of a great variety of food sources.
Should we eat what our ancestors ate?
Even if our ancestors did eat a certain way, eating like them may be overrated. Consider that our ancestors did not have a nearly unlimited supply of calories as we do. In fact, acquiring food was their full-time job. And it took work. It was physical work over long hours, which required a great deal of energy. Our ancestors, therefore, were likely in constant risk of energy deficit. Our situation is quite different. We are in constant risk of energy surplus. We simply take in more calories than we expend. This is the most potent driver of obesity and related diseases. No matter how many days per week Paleo enthusiasts do an hour of CrossFit before spending the day at the office, they are not going to approach the daily energy output of our Paleolithic ancestors. The diet that our ancestors ate, whatever it consisted of, was appropriate for their lifestyle, but not necessarily ours. Meat, as a calorie rich food source, may have been desirable for people constantly at risk of energy deficit. The last thing we need to accompany our sedentary lifestyle is more calorie dense food.
Can we eat what our ancestors ate?
While we don’t know how much meat our Paleolithic ancestors ate, they certainly didn’t eat domesticated beef or pork. If they did eat fowl, it didn’t resemble anything we eat today. Their most abundant meat source had to be what was easiest to catch and kill, which was probably more similar to squirrels and mice than cows and pigs. The meat we eat today is far from Paleo in its nutritional comparison to the meat that our ancestors ate. Wild game would be closest. How many Paleo dieters are using this as their main protein source? Even the recommendation that we consume a similar amount of protein as our ancestors is difficult to follow considering that the range of estimates is so broad, and that the upper level of the range would most likely be toxic. The domesticated plants we eat also differ significantly from the wild plants our ancestors ate.
What is the potential health risk?
It is clear from examining multiple sources of information regarding the Paleo Eating Plan that relatively high meat consumption is part of the plan. This is true regardless of the source of the Paleo information. In fact, meat is often listed before fish and seafood, and before fruits and vegetables. This represents a disconnect between the Paleo Plan and the majority of scientific studies on the relationship between red meat consumption and risk of various diseases, including cardiovascular disease and certain cancers. The body of scientific research supporting this relationship is abundant. Anyone interested in the detail can easily find numerous studies with a simple search in Google Scholar or through your local public library. Red meat consumption has been linked to increased risk of atherosclerosis, stroke, coronary artery disease, colorectal cancer and diabetes. While the exact mechanism for this relationship is not fully understood – our knowledge is constantly evolving – the current evidence is clear that meat consumption correlates with disease and mortality risk.
The Paleo people argue, “But what about our ancestors, they were healthy and ate lots of meat. They weren’t all dying from these ‘diseases of civilization.’ It must be the milled grains and legumes.” Atherosclerosis, coronary artery disease and stroke are diseases of aging. They usually do not manifest until later in life. Our average Paleolithic ancestor did not live long enough to suffer the effects of these chronic diseases. However, CT scans of mummies up to 5,000 years old from various cultures show development of atherosclerosis. Most likely, these individuals died from some infectious disease or injury before heart disease could do them in.
What is the bottom line?
If you want to lose weight, any plan that eliminates entire food groups will probably work if adhered to. Elimination plans however, are not necessarily the most healthy or sustainable. To eat as healthfully as possible, take the Paleo recommendations and rearrange the order a bit. A better order would look like this: vegetables, fruits, healthy oils, nuts and seeds, fish/seafood, meats. Reduction in starchy foods, without total elimination, is a positive goal considering our over-reliance on these foods, especially the highly refined variety. What you end up with is similar to the Harvard School of Public Health Healthy Eating Plan, which is a good place to start a quest for balanced and healthful eating.