Tuesday, May 15, 2012


Sorry again for the lack of updates – the thesis is finally done!  I graduate on Sunday! If all goes as planned I will have a baby in 7-12 weeks! (Holy shit, how did that happen?)

So yeah, there has been a lot going on.

But before I catch you up on that stuff, I wanted to take a moment to reply to some great comments I got on the last post. 

Lou de B made some great critiques that I would love to address.  Here is Lou’s comment, reposted for archival purposes:

Ok, but here is the thing. First the disclaimer: I am a linguist, not a medical Dr. I am overweight so this is not a thin person ranting at fat person thing. I have a long line of short tubbies above me on my Mum's side. But...

you cannot deny that obesity is a bigGER problem in the US, Aust etc than in - say - I dunno, Siberia. And that we just happen to be those that eat HUGE servings and a load of crap. In the US (I've been a dozen times or so) I have so much trouble remembering to ask for small everything so I get something equal to large in Aust. I am not kidding. Some of those coffee or drink cups are buckets. Not cups.

IF people are not drinking gallons of sugar etc AND they are still overweight, then sure, they can be healthy. I bushwalk, climb, canyon etc as do many friends who are overweight and fit. But if I'm drinking gallons of soft drink (you call soda) then my Dr should tell me to stop it. It isn't good for my health. Or my joints (which is where I'm having trouble).

This is not to deny other issues. I read The Beauty Myth at Uni and Real Gorgeous by Kaz Cooke etc. I'm very aware of the role of the media to distort images etc. But being overweight DOES lead to an increase in some conditions AND we did not evolve joints etc to be that size.

Feel free to rip all this apart. I know you know more than me!! And I ought, I guess, just read your thesis when it's done.

So let’s break this down point by point (mostly because my brain used up all its transition sentences over the past 9 months).

1. Obesity is more prevalent in the US and Australia than in places like Siberia.

This is absolutely true.  According to data collected from 1994 to 2002, the prevalence of obesity (BMI >30) in the US is 27.6% for men and 33.2% for women (Baskin et al 2005, "Prevalence of obesity in the United States"). According to a 2005 paper (Thorburn, "Prevalence of obesity in Australia") the prevalence of obesity in Australia is 19% for men and 22% for women. I could not find data for Siberia specifically, but in Russia as a whole, in 2000 the prevalence of adult obesity was 16% (Jahns, Barturin, & Popkin, “Obesity, diet, and poverty: trends in the Russian transition to market economy”). 

2. The places where obesity is more prevalent have larger serving sizes and more junk food and soda.

I can’t find any articles to specifically support this, but based on my personal experience alone, I agree.  (I know that is really flimsy, but stick with me, I will do more research on this in the future.)

That being said, the implication here is that the larger serving sizes are responsible for the increased prevalence of obesity in the US.  There are a ton of differences between the US and Russia – we could really pick any of them and make an argument.  For example, it is colder in Russia than it is in the US.  Thermogenesis burns calories.  Therefore, the temperature difference could be responsible for the difference in obesity prevalence.  I’m not saying I believe this to be true, I am just saying that the causes of obesity are very complex and singling out any one thing is unlikely to be instructive.

3. It is possible to be fat and fit.

Yes, yes, a million times yes.  This is one of the concepts that a lot of people have trouble accepting, because we have been so conditioned to believe that fat = unhealthy.  Here is one of my favorite graphs that I found in my research (Matheson et al, 2012 “Healthy Lifestyle Habits and Mortality in Overweight and Obese Individuals”):


This study looked at four different healthy habits – eating 5 fruits and vegetables a day, getting moderate exercise, not smoking, and drinking in moderation.  Researchers grouped people according to how many of these healthy habits people had adopted (0 – 4 on the X axis) and then further divided people based on BMI (normal weight, overweight, or obese).  On the Y axis, you have mortality hazard ratio – the risk that someone will die prematurely compared to a thin person with all four healthy habits.

So, for people who have none of these healthy habits, we see that BMI matters – those in the obese category are 7 times more likely to die than thin folks with all four healthy habits, while those in the normal weight category are only twice as likely to die.  However, as people adopt more healthy habits, the difference between the normal weight and obese groups disappears. 

Remember, these people are not losing weight as they adopt the healthy habits, because they are still in the obese category.  Just having the healthy habits is enough to change their mortality risk, independent of weight loss.

I would also like you to look closely at the middle bar of each group – the overweight category.  As soon as overweight people have just one healthy habit, their mortality risk is actually lower than normal weight people.  (This is a whole separate rant for another day).

4. Some fat people are not fit – they have poor health habits such as drinking soda.

This is absolutely true.  There are also thin people who drink a lot of soda.  This is a poor health choice in either group.

5. Doctors should tell fat people with poor habits to improve their habits for the sake of their health.

Yes, I agree.  Doctors should tell their fat patients that drinking two liters of Pepsi a day is not a great choice.  But there are a number of caveats I would add:

  • ·         The purpose of lowering the Pepsi consumption should not be to lose weight, because it is unlikely to be effective.  I know, I know, it seems like eliminating 830 calories from the diet would cause weight loss, but long term, a ton of research suggests that this isn’t the case (Mann et al, 2007 “Medicare’s search for effective obesity treatments: diets are not the answer”).  The leptin feedback loop is a squirrely little thing. 


  • ·         Instead, the point is just to replace that space in your stomach with some fruits or vegetables.  We actually have proof that eating fruits and vegetables is good for you (it’s one of the healthy habits in the Matheson study above).


  • ·         Suggesting that a patient stop drinking soda is something that a physician should do from a place of understanding of both the broad environmental factors that surround consumption in general and the individual factors that affect that patient’s life.  Pepsi’s 2012 advertising budget is $1.7 billion.  (That’s Billion, with a B!) I’m just some schmuck in a white coat and I certainly don’t have $1.7 billion.  Also, if my patient is the single mother of three kids working two jobs and drinking some Pepsi to stay awake through the third shift…nagging her would be poor form.  And by ‘poor form,’ I mean judgmental and insensitive. (Though plenty of doctors think nagging is their Hippocratic duty).


  • ·         Doctors should also tell their normal weight patients not to drink two liters of soda.  It’s not just unhealthy for fat people, it’s unhealthy for everyone. The other side of the ‘fat = unhealthy’ assumption is that thin = healthy.  But as we see in the above chart, thin but sedentary, drinking, smoking, and eating crap still makes you twice as likely to die prematurely.  Bringing the focus back to habits rather than bodies means bringing the focus back onto things we can actually control that are more likely to make a difference.


6. Though there is cultural bias against obesity, obesity is still legitimately linked to increased morbidity and therefore is a medical problem.

This is probably the part of Health At Every Size that I struggle with the most.  I feel like some of the more zealous Fat Acceptance folks try to argue that obesity has absolutely no corresponding health risks. 

Are all the studies of obesity and health risks done in an environment of unrecognized fat phobia so that all their results are suspect?  Yes.  Much the way those old fashioned studies about how the Negroid skull was associated with lower intelligence were conducted in an environment of racism – the world view of the scientists absolutely colors the results. 

Do almost all the studies of health effects of obesity fail to control for obvious confounding factors like health habits and socioeconomic status? Yes.

However, I still believe there are some negative health consequences of obesity.  The data on hypertension is pretty convincing.  Also, the joint issues you bring up are a great example.  That’s just physics – more weight on those joints causes more degradation.

But, as we have seen, the cause of obesity is outside of an individual’s control and weight loss efforts are unlikely to have long term success.  So yes, I think it is silly to say that obesity has no health consequences, but I also think it is silly to say that because there are negative health consequences people need to just try harder. 

Age is also linked to joint problems, cardiovascular disease, and cancer.  And physicians use this information when calculating a person’s disease risk, but no one suggests their patients try really hard to age more slowly.  And I’ve certainly never heard of a doctor refusing to treat the patient until they successfully get younger.

 

So yeah, I hope that helps flesh out my stance – I look forward to your responses/questions/etc!

Also, now that I have learned how to add pictures – here is a picture of me, planting some vegetables.  Which I totally plan on eating at least 5 of per day.  As soon as they grow up.  


3 comments:

  1. Nope that pretty much covers it I think!! I picked Siberia just because. But actually a better one would be France. My French friends can't beLIEVE the crap we snack on (chips etc). They lived in Aust for 5 yrs or so. Over there, they eat lovely fatty cheeses, drink lots of wine, and at least of the sample of Frogs I know they are all normal looking weight (according to what I imagine their BMI is).

    But your answers were all good. LOVE the graph. I will probably use that in teaching. (Teaching stds how to read graphs, and how to present data; not teaching health!) So could I have a reference? Really good graph.

    ReplyDelete
  2. It's ok. I've found it. Though what is the Journal of ABFM stand for???

    ReplyDelete
  3. American Board of Family Medicine! Thanks for reading, and I am glad you love the graph!

    ReplyDelete