Tuesday, July 15, 2008

How to communicate weight loss messages to patients

A college friend of mine wrote in her live journal about her reaction to a doctor's initiation of the topic of weight at an appointment she had to address a recent injury. The doctor's approach seemed to be attempting to be non-intrusive: she gave a neutral factual statement that my friend looked from a picture like she used to be lighter. What happened next was interpreted as my friend as "asking if I knew I was going to DIE OF THE FAT."

Clearly something went wrong here in the immediate clinical encounter. Probably the doctor should have sensed from the conversation that my friend wasn't terribly open to discussing the subject and found it intrusive, especially since weight was completely irrelevant to the purpose of the appointment. If the doctor didn't want to just let the subject drop, she could have at most asked neutrally how she felt about that difference, and let it drop when my friend said that she felt fine.

But there's a larger question: how do physicians manage to acknowledge fat acceptance, but also send a message of obesity prevention?

Contrary to the blog comments, research is clear that on average mortality increases monotonically with BMI. Walt Willett's book has some nice plots of this. Fertility decreases monotonically with BMI. Even if recent research showing mortality improvements for some diseases in the BMI range 25 to 29 is completely free of confounding, so it's the weight which is associated with the decreased mortality rather than another factor that wasn't adequately adjusted for, it's only for a few of the evaluated diseases and mortality is much higher for BMI over 30.

Not to belabor the obvious, but these studies can only be refuted by studies of similar validity. They're not a massive conspiracy against anyone. They're just what the data revealed. Anyone who wants to reexamine the data to find a better explanation or find deemphasized null findings within the reports is free to do so, but so far no one has. And it's not impossible. See this reexamination of Framingham Heart Data on diet and cholesterol.

Anecdotes about outliers are just that. The studies hold on average, and while no one likes to think of themselves as average, all of us are average in most domains of life.

How can the overriding medical evidence be communicated in this sensitive way? I don't know, but here are some stabs at some of the issues:

- Many people feel powerless to change their weight, or feel that only heroic efforts can be successful. There does seem to be such a thing as a weight setpoint which is clearly resistant to change, see e.g. Gina Kolata's book.

- If it's not possible to change weight and live one's life in what one feels as a reasonable way, it makes a great deal of sense to accept weight as a given, and to see messages about overweight as taunting from people who just don't understand. Especially since sometimes they are.

- A never-overweight person sees their entire relationship with food, hunger, meals, clothes, and society completely differently and may therefore say stupid things like "Just lose weight," when it's anything but "just." Even the statements like "even 10 pounds makes a difference" while well-intentioned don't entirely help. One of the nicest but perennially thin people I know once said, "you're not that fat."

- It's not that easy, but it's usually not impossible either. In the spirit of self-discovery and self-experimentation while attaching no emotional weight to the results, people can design tests of the many approaches to food and diet, a few weeks long for each, to see whether anything changes their relationship to food or their weight.

And there are so many: beyond the obvious popular ones, the support-group types, there's the most kooky-seeming and yet potentially most profound by Berkeley psychology professor Seth Roberts.

-Logically, of course, it's not possible to prove a negative; it's not possible for people to prove what they perceive as reality that "weight loss is impossible for me" or "weight loss is only possible for me at an unacceptably high physical or emotional cost." But honestly these questions of obesity prevention and fat acceptance have such high emotional content on both sides that it's hard to say that there's much logic left.

No answers here, but maybe useful questions come out of it.

No comments: