You’d be forgiven for thinking that I have some kind of chip on my shoulder about Professor Tim Noakes. Well I don’t. But I do have a problem with his method of cherry-picking data to suit his purposes. Let me clarify: yesterday one of his Twitter followers linked to a public lecture given by Noakes, with the comment that ‘watching this lecture … could be the single best thing you do this year for your health.’
Note that this claim is not aimed at anyone specific, for instance, to those who might be pre- or actually diabetic, or glucose intolerant. It suggests that anyone and everyone could do well to listen to Noakes’ advice. But Twitter is a naturally limited space, and my issue is not really with the poster, so let’s leave that there (for now).
The content of the lecture will be familiar to anyone who has attended or watched any of Noakes’ other talks, which is to promote LCHF (Low-Carb Hi-Fat) as a healthier alternative to the “Prudent Diet,” and particularly for those who, like Noakes, are pre- or actually diabetic (he used to refer to himself as pre-diabetic, but last week spoke of himself as a diabetic), or “glucose-intolerant”, or “carb-resistant”.
Here’s a screen shot of the slides he uses as “evidence” of some of the “negative consequences” of the Prudent Diet:
Now, I can appreciate that the point here is to underline (as the original Tweeter pointed out) that supersized people were an anomaly at the turn of the twentieth century, but are now a very normal sight. But to choose an overweight/obese person as an example of the failings of the recommended dietary guidelines is, to my mind, a very poor choice, because it’s very likely that that person did not become overweight or obese as a result of following the recommended dietary guidelines, but rather – probably, in all likelihood – of not following recommended dietary guidelines. And, yes, I don’t know the particular story of this particular cop (could be genetic? metabolic syndrome? maybe he really eats rice cakes and cottage cheese and does ab crunches all day long, much to his frustration?), but neither, I would venture to guess, does Tim Noakes.
Nonetheless, in response to my pointing out that this looks like an example of cherry-picking (only using or including evidence that supports your hypothesis), Noakes challenged me with the following:
‘Prospective Women’s Health Initiative proves Prudent Diet worsens health of those with CHD [Coronary Heart Disease] and diabetes. Cherry?’
The WHI, for those of you who aren’t familiar with it, was a huge study ‘designed to test the effects of postmenopausal hormone therapy, diet modification, and calcium and vitamin D supplements on heart disease, fractures, and breast and colorectal cancer‘.
So, let’s see. If you use the results of a highly contextualised study (not only looking at specific therapies for specific conditions, not including diabetes, but also only looking at postmenopausal women) to advance a general theory about the unsuitability of a particular diet to the general public, is that an example of cherry-picking? I would say a resounding yes.
Time limits prevent me from ranting any further about this here and now, but let me also add that the “big news” released today that “Overeating now a bigger problem than lack of food” does not mean that obesity is a bigger problem than world hunger. Well, it does on the “disease burden” scale used in this study, but note that one of the reasons that overweight people have more diseases is because they are generally living longer due to increased global life expectancy. What a paradox: science keeps people alive longer so they can experience more disease. And why are undernourished people less likely to have more diseases? Probably because they die without food.
What’s the key dietary risk factor associated with disease? A diet low in (high carb) fruits. Go figure.