Author: Seth Roberts

Comparison of Strategies for Sustaining Weight Loss

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A recent issue of JAMA has an article titled “Comparison of Strategies for Sustaining Weight Loss: The Weight Loss Maintenance Randomized Controlled Trial”. It reports an experiment that compared three ways to keep from regaining weight you’ve lost.

If you want to lose weight it paints a discouraging picture. It was an very expensive study, 27 authors, five grants. About 1000 subjects. Four years just to collect the data. The whole thing might have taken seven years. Must have cost millions of dollars. Might have cost tens of millions of dollars.

Given the huge expense, surely the subjects got the best possible establishment-approved weight loss advice. They did lose 19 pounds in six months. Here’s how the advice was described in the article:

Intervention goals were for participants to reach 180 minutes per week of moderate physical activity (typically walking); reduce caloric intake; adopt the Dietary Approaches to Stop Hypertension dietary pattern . . . and lose approximately 1 to 2 lb per week. Participants were taught to keep food and physical activity self-monitoring records and to calculate caloric intake.

Shades of Marion Nestle’s “move more, eat less”! Aside from the DASH “dietary pattern,” which was meant to reduce blood pressure, not weight, this advice could have been given fifty years ago. Apparently, those who did the study and those who funded it — who are representative of the larger research establishment, I assume — believe there has been no theoretical or empirical progress since then.

Many fields haven’t progressed in 50 years. Fifty years ago, 2 + 2 equaled 4. The basic principles of thermodynamics and inorganic chemistry were the same then as they are now. Lack of progress in weight loss advice would be fine if the advice actually worked but the whole study derived from the fact that the advice is poor — the weight loss it produces cannot be sustained.

To help people sustain their weight loss, the study compared three methods: 1. Monthly contact. Usually a 10-minute phone call (“with an interventionist”), every 4th month a hour face-to-face visit. Although the article claims this treatment was “practical,” I suspect it is too expensive for widespread use. 2. Encouragement to visit an interactive website. The website helped you set goals, allowed you to graph your results, and had a bulletin board, plus several other features. This was the focus of the whole huge research project: the effect of this website. It could be offered to everyone practically free, except that if the subject didn’t log on after email reminders she got a phone call. 3. “A self-directed comparison condition in which participants got minimal intervention [that is, nothing].”
The personal contact condition was slightly better than nothing. By the end of the study, the website was no better than nothing. And nothing was bad. The subjects regained about two-thirds of the lost weight during the maintenance year and, looking at the weight-versus-time graph, were apparently going to regain the rest of the lost weight during the coming year. Subjects in all three conditions continued to regain the lost weight throughout the year of maintenance.

In other words, this exceedingly expensive study could be summed up like this: We tried something new, it didn’t work. The abstract didn’t face this truth squarely. It concluded: “The majority of individuals who successfully completed an initial behavioral weight loss program maintained a weight below their initial level.”

It’s a Catch-22: Without a good theory, it’s hard to find experimental effects. You’re just guessing. Most of what you will try will fail. Without strong experimental effects, it’s hard to build a good theory. I was in this situation with regard to early awakening. I had no idea what the cause was. It took me ten years of trying everything I could think of, dozens of possibilities, before I managed to find something that made a difference. From that I managed to build a little bit of a theory, which helped enormously in finding more experimental effects.

The people who did this study had no good theory about weight control. Nothing wrong with that, we all start off ignorant. The website they tested was just the usual common-sense stuff. What’s discouraging for anyone who wants to lose weight is how little progress was made for such a huge amount of time and money. If it takes seven years and ten million dollars and a small army of researchers to test one little point in a vast space of possibilities . . . you are unlikely to find anything useful during the lifetime of anyone now alive (or any of their children). The people behind the study also had a poor grasp of experimental design. With 300 people in the website group, it would have been easy to test many website design variations: weight-loss graph (yes or no), bulletin board (yes or no), etc., using factorial or fractional factorial designs. Their study merely showed that one particular website didn’t work. They learned nothing about all other possible websites. They might have been able to say: no likely website will work. They can’t because the study was badly designed. The study cost something like $10 million and that was the statistical advice they got!

The huge expense and the lack of progress in the last 50 years go together. The methodological dogmatism I discussed recently has bad consequences. It leads to studies that are more expensive and take longer. The proponents of the methodological rigidity say they are “better” not taking account of the cost: continued ignorance about health. A better research strategy would be to fund and encourage much cheaper ways of testing new ideas.

The Amish and Organic Farming

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One modern invention accepted by Pennsylvania Amish farmers is pesticides: They use horses to pull pesticide dispensers. This may play a part in an increase in birth defects in their community, which are usually explained by inbreeding. (However, large increases over short periods of time are almost always due to environmental changes.) A few years ago, Sally Fallon, head of the Weston A. Price Foundation, was part of a group visiting an Amish farm that had recently become organic (i.e., stop using pesticides). Someone asked the farmer why he had decided to change. Show them, he told his son, who had been standing with his arms behind his back. One of his arms had no forearm. We took that as a sign from God, said the farmer.

Bryan Caplan on How to Lose Weight

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My self-experimentation inspired Bryan Caplan to do his own self-experiment: Could he lose weight by eating less without discomfort? He did two things:

1. Stopped eating when he wasn’t hungry. During a meal he began to pay close attention to how hungry he was. When he stopped being hungry, he stopped eating, even if it meant leaving food on his plate. Before this he rarely left food on his plate. Now it was common.

2. Cut down on his soda consumption. Previously he was drinking at least two cans/day of Coke or IBC Root Beer (both non-diet). He reduced this to one can/day, which he found was enough to keep his energy up.

Bryan is 5′ 10″. When this started he weighed about 178 pounds. Over 9 months, his weight went down to 155, where it has remained for 9 months. “Is this something I’m willing to do for the rest of my life?” he asks. “Yes.”

I’m sure that non-diet soft drinks — primo ditto food — are very fattening but it isn’t easy for me to believe that cutting back on them could cause so much weight loss. Did the don’t-eat-when-not-hungry rule also help Bryan lose weight? I don’t know of research that answers this question.

Tyler Cowen on Blogging

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“I can say what I really think,” said Tyler about blogging a few days ago. Not only that, (a) this truth-speaking is on a topic he cares about, (b) what he says is based on considerable knowledge (what an ignorant person “really thinks” about something isn’t helpful), and (c) a lot of people listen. This is a potent mix.

The magic of blogging is that when you start you can tell the truth because no one is listening. With zero audience, it makes sense — it feels good — to tell the truth. If you are an expert like Tyler, this sort of thing is irresistible to readers (economics confidential) so your audience grows. Now it is too late to start censoring yourself; people are reading your blog because you tell the truth.

Tyler’s blog.

Empowering Patients

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Speaking of empowering patients, this is incredibly important.

He clicked on baclofen, and the Web site informed him that nearly 200 patients registered at PatientsLikeMe were taking the drug. He clicked again, and up popped a bold bar graph, sectoring those 200 across a spectrum of dosages. And there it was. Contrary to what his neurologist told him years ago, 10 milligrams wasn’t the maximum dose. In fact, it was at the low end of the scale. “They’re taking 30, 60, sometimes 80 milligrams — and they’re just fine,” Small recalls. “So it hits me: I’m not taking nearly enough of this drug.” A few days later, Small asked his neurologist to up his dosage. Now Small takes 40 milligrams of baclofen a day. His foot drop isn’t cured — there are no miracles in M.S. — but he has found that after 14 years, he can walk to his car without sinking into quicksand.

Long ago diabetics did not have access to blood-glucose meters. Doctors resisted this innovation, now considered the greatest advance in the treatment of diabetes since the discovery of insulin.

Thanks to Tyler Cowen.

Robin Hanson on Doctors

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I am visiting George Mason University. Yesterday, as I was answering email, I heard a class in progress on the other side of the partition by my desk. It was Robin Hanson lecturing about the economics of health care to 20 undergraduates. It was so interesting I ended up listening to about 90 minutes of it. “Do your students know what a great class they’re getting?” I asked Robin during a break. “I don’t know myself,” Robin replied.

I have heard hundreds of professors lecture. I had never heard anything like this. It wasn’t the usual stuff. It wasn’t the usual stuff made entertaining with cartoons or demonstrations or jokes or war stories. Instead, it was a straightforward look at how the medical profession operates, and a lot of it was about how it operates to empower doctors, reduce the power of patients, and reduce health care innovation. Robin traced the history of the profession from the 1800s until today. “What separates a trade from a profession?” he asked his class. Professionals have ethics, he said. Doctors devised a code of ethics. At the top was “first, do no harm.” What does this mean in practice, he asked his class. If a patient dies, does the doctor feel shame? No. If a patient wants a medical procedure that isn’t recommended, does this mean the doctor doesn’t do it? Apparently not. In contrast to the remarkable vagueness of “first do no harm” the rest of the doctors’ ethics code was quite clear: no practice without a license, no advertising, and so on — each item with clear economic implications.

Robin also discussed how little doctors are supervised. A British doctor managed to kill over 200 people before anyone noticed; he was finally caught only because he forged a will. A nurse at a local hospital was assigned to measure how often doctors wash their hands. They’re supposed to always wash their hands but many do not. The nurse did the survey, and, as requested, correlated hand-washing compliance with death rates. It turned out that the doctor who washed his hands the least had the highest death rate. The nurse reported this. The exceptional doctor had her fired.

On and on like this. Several books cover bits of this territory. A Sacred Trust by Richard Harris, very well written, is about how the AMA fought public health legislation. Overtreated by Shannon Brownlee, which Robin assigned, is a recent overview. The nice thing about Robin’s critique is that it was very accessible and at the right level of detail — I didn’t have to spend 10 hours reading a book to learn what Robin said in 20 minutes — and it was very wide-ranging. During my last visit to GMU, Robin had told me about the RAND study that found groups with different access to health care had the same health. Uh-oh. This was a much broader, more narrative look at same thing — how well is our health care system working? — and was a kind of explanation of the results of the RAND study.