Monday, July 23, 2012

The Paleo Diet: Follow-Up V

Okay, I finally got around to digitizing all of my secondary data (from my doctor's records, lab tests, and United Blood Services) relevant to the efficacy of my dietary experiments and merged it with my primary data (the data I collected myself), so I am now in a much better position to make an final appraisal than previously was the case. Also, thanks to my recently acquired programming skills (although still rudimentary at this point) I was able to reorganize my data so that all of the points share the same date format, which should make it much easier to visualize the passage of time (rather than merely the passage of measurements) in my graphs than before.

Firstly, did I lose weight? I already had a high degree of belief that this was the case (from clothing fit and pictures taken during this time period), but since I started recording my weight daily simultaneous with beginning the diet, my assessment lacked the degree of objectivity I think appropriate for these kinds of things. Here is a graph including all of the information about my weight that was available to me at the time of this post (which includes datapoints further in the past than my original analysis):


As you can see from the graph (the "lumpiness" in the first half is due to the relative poverty of information I have about myself from before I became a self-tracker), I was slowly gaining weight during the year leading up to the start of the experiment. The weight loss I did experience started immediately upon starting the diet and continued at a fairly rapid rate for months before slowing down and then oscillating between values that the Singapore Government's Health Promotion Board deems a "healthy range".

Secondly, did I maintain my strength and endurance? When I started my diet I went to the gym 4-6 days a week, alternating between running and weight-lifting. I currently go to the gym 4-6 days a week, alternating between running and weight-lifting. All of my lifts have increased in weight while keeping sets, reps, and rest periods constant. Also, I now run at a higher rate of speed for the same amount of time (and therefore, am running a greater distance). 

Thirdly, has my health suffered? Subjectively, this is an obvious no. My body feels better along almost every imaginable dimension. On the other hand, the placebo effect can be quite powerful and the human capacity for self-deception almost limitless. Since the most common argument against the efficacy of the Paleo Diet for long-term health is that high-fat diets increase the chance of getting heart disease and stroke (although, bacterial infection and calcium deficiency are also fair worries), I have decided to concentrate on measures of cardiac health.

The American Heart Association recommends a systolic (maximum) blood pressure of between 90-119 mmHg and a diastolic (minimum) of between 60-79 mmHg. Blood pressure can very quite a bit throughout the day and between days, so the average is more important than any individual measurement. Before starting the diet my average systolic blood pressure was 115 mmHg, but the sample includes only 4 datapoints which isn't enough to know with much certainty what the actual value was during this time period . In any case, the average from after starting the diet until now (including 119 datapoints, which allows us to be fairly confident in the result) is 112.6 mmHg.


Pre-Paleo my diastolic blood pressure came out to an average of 64.8 mmHg, while afterward it ended up being 61.8 mmHg.


As is apparent from the graphical representations of the data, my blood pressure started out in the AHA's "desired" category and ended up in the same category. Interestingly, in both cases, my average blood pressure decreased after starting the diet.

Cholesterol is generally considered (by the medical profession) to be a measure of heart health, but Paleo advocates disagree. The following graph shows my total cholesterol levels before and after going on the Paleo Diet:


My average total cholesterol started out at 154.2 mg/dL, but is now 201.3 mg/dL. This appears to be an unfavorable change (assuming the consensus in the medical field is correct), but only barely puts me over the edge between "desirable" and "borderline high". While perhaps worrying in isolation, in conjunction with the fact that my post-experiment ratio of total cholesterol to HDL cholesterol is 2.9:1 (which easily falls into the AHA's recommendation of "less than 5:1") it doesn't seem to be a serious threat to my cardiovascular health.

In short, I lost a significant amount of weight, increased my strength and endurance, and probably didn't endanger my health in any other way. This is essentially the same as my initial appraisal, but my confidence in this result is now significantly greater due to the much larger quantity of data and the extended time period (incorporating "new" data from both before and after my original post) used in this later analysis. I am now comfortable making the claim that if you are like me in relevant ways (especially if you are closely related to me), then you should worry a little less about eating large amounts of fat and worry a little more about eating things high in processed carbohydrates.

2 comments:

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