Monday, February 24, 2014

Medicalizing obesity: What is a 'disease', anyway?

Last June the American Medical Association, along with a number of specialist medical groups, voted to consider obesity to be a 'disease', and released a policy statement explaining why, and what they propose to do to treat it.  

A disease, by their definition,
1) is an impairment of the normal functioning of some aspect of the body;
2) has characteristic signs or symptoms; and
3) causes harm or morbidity.
The statement details the reasons that obesity meets this definition, and then provides a substantial list of recommended actions.  It is worth nothing that the first, in a seven page list of recommendations, is that "Our AMA will: (1) urge physicians as well as managed care organizations and other third party payers to recognize obesity as a complex disorder involving appetite regulation and energy metabolism that is associated with a variety of comorbid conditions…"  That is, in plain language: as a disease, obesity should be covered by insurance.

Is this just a ploy for a big financial golden egg?  One might be a lot more cynical about about this if the statement didn't include some recommendations for prevention; healthy school lunch and exercise programs, encouraging reduction in the price disparity between fresh and processed foods.  They even include recommending healthy food at AMA meetings in their statement.  We'd be even happier if nutrition science could tell us at all definitively what "healthy food" is.

Jogging in Central Park; Wikipedia

Even so, this strikes us primarily as the medicalization of obesity.  The statement justifies this by saying that bariatric surgery, pharmacological approaches and lifestyle interventions can now help people to lose weight and thus reduce the consequences of obesity; type 2 diabetes, heart disease, stroke, breast cancer.  If they are so successful, though, why does the same report include the prediction that 50% of the US population will be obese by 2040?  Not overweight: obese.

An editorial in yesterday's New York Times, 'Should Obesity Be a "Disease"?', by Crystal Hoyt and Jeni Burnette, two psychologists, asks whether there are negative consequences to the AMA's decision.   Does it make a difference psychological and/or medically if obese people consider themselves diseased?  "Would it reduce or add to the burden of body-image concerns and shame? Would it empower people to fight back, or lead to a fatalistic acceptance of being overweight?"

So, they did a study.  Or, three online studies, of over 700 obese people. They assigned a news story about the AMA's decision to one group, a story about how obesity is not a disease to another group, and a public health message about weight loss to another group, and then asked them some questions.

They found that the people who read that obesity was a disease were more apt to have a positive body image than the other groups. But, there was a down side to thinking of obesity as a chronic illness. "Suggesting that one’s weight is a fixed state — like a long-term disease — made attempts at weight management seem futile, and thus undermined the importance that obese individuals placed on health-focused dieting and concern for weight."  Hoyt and Burnette conclude:
Ideally, we would have a public health message that leads to a decrease in self-blame and stigma while at the same time promoting adaptive self-regulation and weight loss — both equally important components of the fight against the obesity epidemic. We’ve yet to find an answer to this dilemma.
Obesity is epidemic, meaning that relative weight (for height, say) has become increasingly prevalent in the population.  Assuming this trend is a negative one, one might then fairly consider what its cause is and try to eliminate that cause.  But after countless studies, there isn't a single reason, and if it were easy to lose weight and keep it off, it wouldn't be a problem, or a 'disease', or something that leads to disease. It could even be something good, as it provides people with some energy reserve if they do get a clear disease.  Apparently, even stomach stapling is often not a long-term fix, and it certainly doesn't always change people's mindset about food.  Losing weight is really hard, and keeping it off is even harder, so simply saying that the medical systems needs to promote self-regulation and weight loss is to recommend the impossible.  It may be as resistant to simple correction or prevention as smoking cessation is.

To give the AMA credit, they do give attention to the prevention side, where it needs to be.  As Michael Pollan has written, the food industry produces more calories per day than people need to eat to maintain their weight.  They have to get us to eat it somehow, and they are very good at that.  And, sugar, salt and fat are very tasty, and often go together in high calorie, inexpensive processed foods.

The food industry has very profitably figured out how to get us to eat what they sell, starting at a very early age.  The medical system is now figuring out how to take its cut, by medicalizing obesity.  No one has satisfactorily figured out how to get people thin again, once they've gotten obese, however.  The cure is prevention.  We know that exercise and eating in moderation keep people thin.  But that message is drowned out by the easy availability of calorie dense foods.  Changing that is going to take societal and cultural change.

What is a disease?
This brings up a broader question. What is an 'impairment' and what is 'normal', and who decides?  The 3 characteristics of a disease definition that we listed above are themselves vague, perhaps hopelessly vague.  What does 'some aspect' of the body actually mean?  Since any and everything can have 'characteristic' signs or symptoms, and since 'normal' is not an obvious term, almost anything--say, a tendency to giggle, or to be ticklish--can fit the definition.  Finally, causing 'harm' or 'morbidity' simply passes the buck on what that actually means.

What this shows is that even defining 'disease' is subjective, changeable, and culture-specific.  The criteria are in themselves of no actual use.  They sound scientific and knowledgeable, and from the AMA one might think they are well considered and helpful.  But they really just kick the can down the proverbial road to some other commissions of 'experts'.  By now we should be long past asking whether 'obesity' is a trait, much less a disease.

There does seem to be an issue in regard to obesity, and it does seem to go beyond fashion and style and cultural tastes.  And there really are diseases that we have every right to be concerned about and try to prevent.  But without useful definitions, and data to show that those definitions really mean something, the main people getting fat off of the definitions may be the research industry and people running nice hotels where, after a fine lunch, these definitions are endlessly discussed.


Louis said...

Hm, these calorie in / calories out ideas again. I don't know whether it's calorie-density as you mention but subtler energetic implications of diet. At least, that's what I glean from nutritional studies and my undergrad metabolism lectures. Totally agree that it's hard to gauge what is objectively "healthy" though.

There was a really nice piece in Nutrition Journal recently which rails against a lot of misunderstanding over obesity (including the assumption that obesity is a measure of fitness or metabolic health), and managed to come across very compassionate for what at the end of the day was a review of transaminase variation...

I think you bring up an interesting side to what we talk about by "medicalisation", linking AMA's role as partly to advising an insurance industry - it really is unscientific to consider subjective traits (i.e. with no firm metabolic basis) objectively "morbid" in any case.

There're all sorts of fats, brown, white, beige, even body fat % doesn't really give a good profile since it's just adipose / total mass.

Is metabolic profiling setting insurance premiums too dystopian or not so far off (now that "obesity" could well be in line for the same)? I'm in the UK but there's an undercurrent of privatisation coming to our health system too, ho hum

Anne Buchanan said...

Thanks for this, and the link. You're right, of course, that there's been a lot of criticism of the energy imbalance explanation for obesity. Too often, though, in my view, the alternative explanation is a single factor -- inflammation, leptin, sugar, set point imbalance, the 'western diet', anything-but-the-Mediterranean Diet, infectious disease, etc., and now alanine transaminase activity joins the list.

Maybe it's a single thing, but I doubt it. And, of course the nutrition industry has not been any better at sorting out cause than most other fields, as we noted in several recent posts (e.g., here.) People eat complex diets with multiple physiological effects, and I think it's pretty much always wrong to think we can pinpoint the effect of a single component.

As for whether obesity is a healthy or unhealthy condition, as far as I can tell studies disagree on this, with the ultimate conclusion being that it's unhealthy when it's unhealthy.

And you could be right that metabolic profiling by insurance companies may be coming. But it would be based on the all too common fallacy that we can predict our disease futures.

Ken Weiss said...

There is another indirect but I think rather persuasive reason why it is not a single factor. A single factor, having had greatly increased exposure (hence the new obesity pandemic) would likely have had its effects by interacting with one or only a few specifically factor-related genes.

But genome mapping of obesity-related traits, in many different studies, has shown nothing like that. It has instead shown evidence that many genes with diverse and individually small effects are likely responsible for weight differences.

It's not foolproof evidence, but it's serious evidence, even if indirect.

Louis said...

Yes, definitely ‒ the piece I wrote about brings this up precisely, “the appeal of a simplistic causation and the subsequent holistic acceptance” but then goes ahead to single outs its own preferred idea! This and the post you link to are kind of why I tend not to read (i.e. follow the RSS feeds of) the likes of the Lancet, Sci Transl. Med. etc. I'd never even thought of it as bourgeois industrialisation but hey, I'm open-minded haha !

I popped back here to follow up my comment with a news item just a few hours later that's just… terrifying? As I was just calling dystopian, it turns out our National Health Service has sold the medical records for *every patient in the country* to insurers who went and did all sorts of data analysis to best exploit the market... I'm just… a little shell-shocked to be honest. I don't think it's the same over in the US with privatisation but here the health service feels really personal, it's a public good Fallacy or no fallacy, they seem to think that this big data (or whatever it is) approach will maximise their profits off the sick so I don't doubt they'll try to predict outcomes from socioeconomics along with medical data... In fact I don't doubt they're not already using it as a test set for machine learning algorithms with glee. Anyway, I've moaned enough sorry, I love your blog by the way and Ken's posts too, thanks to both of you for replying so soon!

Anne Buchanan said...

Thanks for your kind words about the blog!

I don't understand who has bought the NHS data, though I do understand your concerns and feeling of betrayal! Was it private insurers? So that they can set rates based on expected life expectancies and so forth? It's interesting that they claim that they can predict with such precision -- when treatments change, of course, there predictions will not longer be accurate.

Ken Weiss said...

The public at large seems too easily manipulated to be able to defend things in the general public interest against selfish greed of those who have more, and want more. If that's what's afoot, then it's another illustration that eternal vigilance by the many against the few, is required.

I personally hope the NHS can withstand this particular siege, whatever it is. I have spent many years, off and on, in the UK, over many years, and have known many people (including one of my own children, who became a UK citizen), who have said they would not give up the NHS, whatever its faults (any huge organization run by humans has faults).

Adina Ariel said...

Unduly focuses on obesity as the true problem. In truth, it is the concomitant hypertension, hypercholesterolemia, sleep apnea, arthritis, etc. that go along with obesity that cause the most serious health problems.