Saturday, July 21, 2012

The Paleo Diet

Thanks to everyone who took a look at my site! I’m looking forward to this new venture and the journey on which it takes me. :)

A friend and her husband are considering the Paleo Diet and asked me what I thought. As I was researching it, I thought it would make a fine second blog entry so here goes.

The Paleo Diet, also referred to as the Caveman Diet, Stone Age Diet or Hunter-Gather Diet was created by Dr. Loren Cordain, a professor at Colorado State University. The basic idea behind the diet is that humans are genetically adapted to function best when consuming a diet of foods that could be found or hunted before agriculture or the domestication of animals. This tends to be a higher protein diet focusing on lean meats, nuts, fresh vegetables, fruits, and berries. The diet excludes dairy and all processed or cultivated foods like grains, beans, potatoes, sugars, bakery, sodas, beer, etc.

I did find some academic research on the Paleo Diet. A 2009 study published in the European Journal of Clinical Nutrition fed 9 healthy, sedentary volunteers the Paleo Diet for a period of 10 days. They found reductions in blood pressure, insulin levels, and improved lipid profiles (cholesterol, triglycerides, HDL, and LDL levels in the blood). There was no change in weight. Another study published in Nutrition and Metabolism in 2010, compared the Paleo Diet to the Mediterranean Diet in terms of how satisfying the diet was. The study was comprised of 29 males with pre-diabetes or diabetes and increased waist circumference (a risk factor for heart disease). The group on the Paleo Diet reported feeling more satisfied, in spite of consuming fewer calories, than those on the Mediterranean Diet. At the end of the 12 weeks, both groups showed lower levels of leptin (a hormone associated with energy metabolism) but those with lower levels of leptin in the Paleo Group were more likely to have lost more weight and inches relative to those with lower levels of leptin in the Mediterranean Group. Both studies noted an intake of Calcium below the recommended levels.

Although these examples show some potential for benefits of the Paleo Diet, we should keep in mind the context of the studies. Both groups were very small, the first group’s meals were prepared for them (nice!), one study excluded women, exercise was not a factor in either, and both studies were carried out during short time periods. There have not been any large, long-term studies of the diet. Note that blood pressure, insulin levels, and lipid profiles can all be positively influenced with other diets and regular exercise. I will also note that Dr. Cordain’s higher education is in Exercise Physiology, which is the study of how exercise and physical activity alter the structure and function of the body. Certainly nutrition is important in the study of exercise and physical activity, but the extent of his nutrition education is not clear.

From a professional nutrition standpoint, the Dietary Guidelines for Americans (DGA) published by the USDA and the US Department of Health and Human Services are the key recommendations based on extensive, quality research. The My Plate icon is based on the Dietary Guidelines. The recommendations include eating food from all five food groups every day (Grains, Vegetables, Protein Foods, Dairy, and Fruit) while limiting the amount of sodium, saturated and trans fats, and refined grains. The Paleo Diet aligns with the recommendations of reducing refined grains and sodium (of which processed foods are a major source), and consuming lean meats. The Paleo Diet excludes whole grains, dairy, and legumes, which are rich sources of essential nutrients.

Many diets create weight loss by eliminating entire food groups and the Paleo Diet fits into this category. Many of them also work, at least in the short term, because dieters usually consume fewer calories when they exclude entire groups of food from their meals. These diets are also usually hard to stick to over time for the same reason. People like the idea of prescribed diets because it seems like it would be simple to find a plan and then carry it out. As if eating better is like a road trip from point A to point B, guaranteed to be without incident, via a single freeway. The truth is that our eating habits are constantly changing and being influenced by our environments. That is why, over time, we tend to slip away from these kinds of diets.

I hesitate to make broad diet recommendations because every individual circumstance is different. However, there are certain ideas that I like to use because they are simple, align with recommendations, and make sense. I love Michael Pollan’s philosophy of “Eat food. Not too much. Mostly plants.” This phrase means to eat real food, not highly processed, in moderate amounts, making sure you eat plenty of vegetables and fruits. Although Mr. Pollan’s formal education is also not in nutrition (he’s a professor of journalism at Berkeley) his philosophy conveys a common-sense wisdom and allows for personal flexibility. I also think that it’s crucial to listen to your body above all else. Awareness is becoming a focus area in obesity research. We often eat for reasons other than hunger, and we may ignore hunger cues or subtle adverse reactions to certain foods. Be a scientist in your own eating. Be willing to learn and make changes to what you eat based on what you notice. How do you feel after eating certain foods? How little food can you eat and still be satisfied? Take time to notice your food before and while you are eating it.

If you want to try the Paleo Diet, in the spirit of being a scientist in your own eating, go ahead and try it! You will likely discover something new that will be useful to you. I would caution that there is not enough research on the long term effects of the diet and the positive outcomes it promises can be achieved by following the Dietary Guidelines. Be aware of potentially low intakes of Calcium and Vitamin D. (It may make sense to take a multi-vitamin.)

Related Links and Readings
The Dietary Guidelines for Americans PDF download:

My Plate Recommendations, you can get a personalized eating plan and see what your recommendations are:

Michael Pollan’s ‘In Defense of Food’, an informative and pleasant read:

WebMD review of the Paleo Diet:

HBO Weight of the Nation
HBO partnered with the Institute of Medicine to produce a documentary about obesity in American. The link below is to one of the 4 main films. You have the option to select chapters; chapter 3 is titled “Why Diets Don’t Work Over the Long Term.”

No comments:

Post a Comment