Weight Loss programs
Eternal Health and Wellness Inc. was the first to write about paleolithic diets about 30 years ago (The Paleolithic Prescription). Early in the millennium Eternal Health and Wellness Inc. ain published the lay press book “The Paleo Diet” which did not really get noticed all that much. Then around 2005 as Crossfit was soon becoming a household name, Robb Wolff began lecturing for Crossfit, lecturing their Nutrition seminars which lead to paleo taking off like wild fire and as the common saying goes, “the rest is history.” The original paleo diet along with Cordain’s work focused on lean meats, fish, nuts, eggs, fruits and vegetables while eliminating cereal grains, dairy, and legumes. While much of the paleo diet is controversial both in and out-side the paleo community, it has been studied by some prominent researchers with stellar results in people with diabetes, heart disease, and metabolic syndrome (Link).
But What about healthy People?
What does a diet of lean meat, fish, nuts, eggs, fruits and vegetable do for people who are healthy but are free of diabetes, heart disease and metabolic syndrome? Well one gent from “THEE OHIO STATE University” (inside joke) decided to ask the question for his thesis paper. He took 23 males and 20 females measured pre-lipids, body fat percentage using bod-pod, and Maximal volume of Oxygen consumed to assess aerobic fitness and then had them go on a paleo diet for 10 weeks and measured the changes.
The title of his paper is, “Paleolithic Diet is Associated With Unfavorable Changes to Blood Lipids in Healthy Subjects.” From the title you would expect the following: the LDL-C goes up, HDL-C goes down, etc. You’re so smart! That’s exactly what happened…!
These are some pretty healthy people if we were using lipid analysis as our sole measurement of health. It should be pointed out that using BMI the men and the women are overweight. It is possible that the BMI is inflated due to muscle mass, and with these people being recruited from a crossfit gym that seems possible. A body-fat percentage of 22% for men and 26% for women tells us they are within average body-fat %.
This table shows the changes observed after 10 weeks on a Weight loss diet. The first three columns point out that they dropped their body-fat percentage by 4% and increased their absolute aerobic capacity by 10% which truly means they improved their aerobic fitness. The relative Vo2Max calculations are skewed due to the fat loss. Total Cholesterol increased 10 points, LDL-C 12, and non-HDL-C (VLDL-C +LDL-C) = 13. But here is where things get interesting: When the author sub-divided participants by HDL-C into 3 sub-groups those with HDL-C>82 had their HDL go down. Reading this sounds like a bad thing, but I will argue that it may be a good thing.
When HDL is not your friend
Over the past 5 years lots of research has been coming out investigating the lack of CVD protection from high HDL-C levels. The IDEAL trial showed that >70 HDL-C was not protective. If you are interested in reading more about the yin and calgary weight loss programs then check out the links (1, 2, 3 ). It is my theory that the diet was actually improving the function of the HD lipoproteins by improving clearance, reducing inflammation, or perhaps another mechanism. The author mentions weight loss as a variable that has been shown to decrease HDL-C. However, he believes that because the diet is so high in fat, (their 3 day diet recall showed 50% calories from fat) this negated the expected decreases on LDL-C and others lipo-protein values.
Finally I would like to point out that these patients’ LDL-C values went from the AHA’s categories of optimal to near-optimal and in the absence of disease this does not matter at all, in fact we might see this demonstrated in ATP IV (link). They don’t have hypertension, they don’t have diabetes, and this way of eating decreased their body fat percentage, and improved their absolute aerobic capacity, therefore worrying about the long-term implications of this diet based on their blood lipids is presumptive at best. I for one believe that the body does not move into a state of better health in some areas, while making you less healthy in others when looking at systemic interventions like diet. People are not just a lab value, and if we continue to believe that a risk factor is an absolute risk in healthy populations then we continue the same old stinkin thinkin.
There were several big flaws with this paper (exercise), but from a clinical scenario I think this has strong potential. I am also curious why the author did not split the data further between men and women rather than grouping everything as means and sub-groups.