Thursday, June 01, 2006

Dr. Roberts responds to my TCSDaily article

Dr. Seth Roberts recently published a book entitled The Shangri-La Diet. The plan it expounds consists of eating one tablespoon of either olive oil or fructose corn syrup an hour or so before meals. This will induce a reduction in appetite followed by weight loss. I wrote a less than favorable review for TCSDaily.

My reason for writing the review was that at the time, his book was number 2 at Amazon.com despite significant misgivings I had about it. I found his supporting evidence lacking in that it was based on "self-experimentation" ie. N equal to 1.

I have received a great deal of email about this piece, most of it negative. Dr. Roberts himself wrote a response as well. I would like to take this opportunity then to respond to him as well as his followers (most of whom don't think too much of me).

First off, my main objection to his book and to the statements he's been making to the media have nothing to do with whether his diet works. I thought I'd made this clear with the following:

"Any judgments I have about the plausibility of his theories are irrelevant to my argument. That I believe the Shangri-La diet will one day be a distant memory is no less speculative than Roberts' conclusions."
This is so because neither he nor I have offered the slightest bit of hard data in support of or opposition to any of his results.

Dr. Roberts has not been shy or circumspect about touting his credentials as an associate professor at University of California, Berkeley. However, despite his status as an academic, he has opted to bypass his own colleagues and the checks and balances of his own profession. Rather he chose to go straight to the lay press.

Why would he have done so? He has published scientific articles in refereed journals on psychology. He's performed studies. Presumably he is knowledgeable about accepted study design and methodology. Why wouldn't he have studied his diet the way researchers normally do when they want to establish the validity of a hypothesis (and I don't mean with a sample size of one) before publishing widely?

Obviously by mentioning his university affiliation, he intended to give the added weight to his conclusions that such a position would appear to justify.

Had he simply been a Beverly Hills secretary (as was Judy Mazel, author of the childish and scientifically unsound Beverly Hills Diet) I certainly would not have held him to the standards I discussed in my article. Of course, understanding the source, her readers would have been justified in doubting her credibility as a serious nutrition expert should they have chosen to.

So people, please, no more emails calling me an elitist for criticizing his work on the basis of its numerous methodological flaws. He opened the door to such criticism by circumventing the very peer review that is as much a part of his world as it is of mine. Dr. Roberts and I share space in much the same ivory tower.

As for specific points that he made:

  • "Dr. Ford seems to be saying that my book is dangerous but on its face this is absurd."

I believe that a casual perusal of my piece will reveal that I made no such claim and in fact never addressed the issue of safety.

  • "Dr. Ford has ignored facts that do not support his conclusions. If you search the Internet for people who are trying my weight-loss ideas, you will find many for whom it is working, often very well, and only a few for whom it has failed (harmlessly). Dr. Ford says nothing about this. "

I'm actually quite surprised that Dr. Roberts would have made such a statement after having read my piece. I criticized him for not subjecting his theories to methodological rigor. He counters this by raising anecdotal evidence despite the myriad of flaws introduced by such "evidence" (case ascertainment bias, selection and reporting biases, the placebo effect and others). Moreover he chastises me for ignoring such stories and saying "nothing about this".

  • "...factual mistakes. (1) 'If Roberts were truly interested in investigating his approach, he should have subjected it to . . . peer review' – implying that I did not. In fact, my Behavioral and Brain Sciences article, which contained my weight-loss theory and support for my weight-loss methods, was peer-reviewed. So was a related article in Chance, which I told Dr. Ford about by email while he was writing his critique. Two is not zero. "

If he had read my article, he would have noted that I specifically addressed his Behavioral and Brain Sciences paper. I characterized it this way: "it was not about validating his hypothesis or conclusions. It was a speculative commentary on the use of self-experimentation as an idea generating tool."

That paper merely cites his weight reduction technique as one of many examples of a hypothesis generated by "self-experimentation". It did not in any way address the question of whether that particular hypothesis was externally validated. His Chance article essentially covers the same ground. Does he dispute this?

  • "Finally, Dr. Ford is a medical school professor. For a long time, medical school researchers have contributed no useful ideas to our understanding of how the average person can lose weight."

It is perhaps best not to reply to such a bold and sweeping generalization.

Dr. Roberts closed his response with the following: "Time will tell which of us is correct." To which I say yes, but only if someone actually studies the diet.

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12 Comments:

Blogger Stephen said...

Gee, given that lap-band surgery appears to have come out of medical science ...

June 01, 2006 4:12 PM  
Blogger Stephen said...

Now, for a serious comment.

What is your specialty and what type of medicine do you teach and practice?

Do you have a PhD or do you just have a professional degree?

Since you are discussing credentials vis a vis conclusions, these are relevant to your postings as a "medical professor."

I also would think you would post on lap-band surgery as it is the medical school approved alternative.

Anyway, look forward to full and honest disclosure from you.

June 02, 2006 4:48 AM  
Blogger The Medicine Man said...

Steve,

Just read the "About Me" part of my homepage (or google me).

John

June 02, 2006 7:06 AM  
Blogger Stephen said...

Ah, "a hospitalist" with no PhD and currently teaching internal medicine.

No publications listed, but I wouldn't expect that in an "About Me."

June 02, 2006 10:21 AM  
Anonymous hgstern said...

 
Ah, the old, reliable *ad hominem* attack. I see, because Doc Ford has no PhD (and this is relevant, how?) and teaches medicine, he obviously has no basis for critiquing Mr (Dr?) Roberts' "work."

Mr/Dr Roberts is not an MD, nor even a DO, yet he is competent to make recommendations regarding physical health? How does that work, exactly?

The fact that Mr/Dr Roberts chose to use strawman arguments in his "rebuttal" implies that he knows that he is standing far from solid ground.
 

June 02, 2006 12:02 PM  
Blogger Stephen said...

I'm not sure that noting the answers to my questions is "Ah, the old, reliable *ad hominem* attack," but appreciate that some see it that way.

Or was it that I noted that he didn't list publications, but that I would not expect them to be listed, that you are complaining about?

Actually, I litigate, successfully, and don't find that "the old *ad hominem* attack" is reliable or useful, because it doesn't persuade

What about my summary was unfair or an ad hominem? How is noting that he teaches medicine a criticism?

Would you feel better about Roberts if he were a chiropractor or a DO?

BTW ad hominem

http://en.wikipedia.org/wiki/Ad_hominem

June 03, 2006 5:34 PM  
Anonymous hgstern said...

I'm sure you have a point in there, somewhere.

Darned if I can find it.

Notice that you still haven't answered my questions (not that I expected you to).

If you're you're relying on Wiki for your definitions, then you definitely need to get out a bit. By attacking the messenger, you (unsuccessfully, in this case) seek to avoid dealing with the message.

Keep trying though, it's entertaining to watch.

June 03, 2006 9:38 PM  
Anonymous hgstern said...

Addendum to Stephen:

I am very sorry about your losses. I can only imagine the anguish and grief that must come from losing a child, let alone three. It's obvious (from reading your site) that you've learned to cope, and for that you have my utmost admiration.

Be well.

June 03, 2006 11:13 PM  
Blogger DRJ said...

i have mixed feelings on the Shangri-La diet, Dr. Ford's response, and these comments. As for the diet itself, it may work or it may not, but I don't see much harm in it unless you have a diet-sensitive medical condition or you use it as an excuse to eat more and exercise less. It would be helpful if Berkeley or some other institution had conducted trials to evaluate the diet prior to publication, but that wasn't going to happen given this is basically a layman-produced diet. At some point, there might be interest in conducting scientific studies if the diet has a groundswell of support through anecdotal reports, such as Stephen's experience and presumably those of others like him. It reminds me of the herb, milk thistle, where patients reported success in using it to treat liver ailments and medical studies followed that confirmed those reports.

I think Dr. Ford has a good point - we want to protect people from quack ideas - but at heart it's an elitist concept to say that what we eat must be subjected to rigorous scientific study by the medical establishment before the public can take it seriously. While I certainly don't read Dr. Ford's article or comments to suggest that the Shangri-La Diet should be censored or withdrawn, I'm not convinced that good health ideas can only come from the medical community. I prefer to educate and empower people to gather good health information and use it wisely, rather than further remove medical decisions from the hands of the consumer in favor of physicians.

June 07, 2006 9:41 AM  
Blogger Stephen said...

Interesting, Roberts has posted an editorial, mostly stating that his reply to the editorial was not well conceived.

http://www.huffingtonpost.com/seth-roberts/the-wisdom-of-strangers_b_25739.html

Take away quote "It made me wish I had solicited comments before I posted my reply."

Interesting.

July 25, 2006 7:40 PM  
Anonymous Anonymous said...

Actually Science News did report a few years ago a peer reviewed article to the effect that drinking a glass of fruit juice an hour before meals diminished appetite. Ford is right, there should be peer reviewed diet study.

In the meantime, it does seem harmless, but remember too that lots of people took tryptophane tablets (which is pretty highly concentrated in turkey) as a "natural sleep aid" and that the whole industry had to be closed down when it was discovered users of this "natural sleep aid" were getting holes in their brains (literally).

I think olive oil is more benign, but the reason peer review double-blind studies got started was was that too many people are willing to believe too many things, many of which aren't true.

March 27, 2007 12:58 PM  
Blogger Concerned citizen said...

I find this whole discussion a bit sterile. As a trained PharmD and Ph.D. I firmly believe the peer-reviewing process as the base of all scientific validation. This being said, what I find of it is: Dr. Roberts speculated on a theory about weight loss. Dr. Roberts is not an M.D. or a nutritionist. The theory had a large acceptance with the public. So now, it's up to M.D.s like Dr. Ford to ACTUALLY prove him wrong or right, and if right, to substantiate the theory with their own expertise and bring up the empty pieces of the puzzle. It is my view that Dr. Ford is mainly concerned about the health of the people who are undergoing the diet and that peer-reviewing on in a more nutrition devoted journal could actually benefit Dr. Roberts' theory.

June 18, 2011 10:40 AM  

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