Monday, August 18, 2008


I've been thinking a lot lately about weight, both mine and other people's. I was made very happy last week when this article received a lot of media attention. Basically, the authors looked at data on 5,440 adults over the age of twenty, including their height, weight, and some lab tests. They also used self-reports of smoking and exercise habits. Overall, they found that inactivity, not weight, correlated with heart disease; so did age, smoking and waist circumference. In their study, 51% of overweight patients (BMI 25-29) had normal blood pressure, cholesterol, triglycerides, and blood sugar.

It's not exactly time to go out and rejoice by eating a gallon of Blue Bell, but this makes sense to me. Our BMI scale takes into account 2 things: height and weight. There are an awful lot of other factors that go into a person's build: gender, bone structure, muscle tone, fat density, etc. Just by BMI, many basketball players and other athletes considered to be in excellent physical shape fall into the overweight or obese categories (of course, I'm not referring to 300-lb linebackers here). Other studies have shown the importance of waist circumference in determining cardiovascular risk. I've seen a lot of people with skinny limbs and a big ol' gut.

This study also shows the other end of the spectrum: the unhealthy but skinny person. I'm sure we've all had thin patients with hypertension, hypercholesterolemia, diabetes, and coronary artery disease. I had a friend in high school who was genetically blessed and very thin. Other girls would (jealously) ask her why she worked out or ate salads--"you don't need to, you're so skinny!" We have this perception that only the fat people need to exercise, that the skinny ones have "made it" somehow, they've won the big prize and can eat cookies dipped in butter all day while sitting on the couch.

This study fits nicely into my personal belief, then: healthy people are active, regardless of weight. They probably eat better, too; not necessarily dieting all the time, but eating balanced healthy meals.

Can runners get coronary artery disease? Sure. I think nothing is truly impossible within the span of humanity (except, perhaps, a man who leaves down the toilet seat). Just as there are marathon runners who are fat (rare, but it can happen), I'm sure there are people who could leave me in their dust, only to have a big MI. It's all about adjusting your risk, just like everything we do in medicine.

Now, this study was just a cross-sectional observational study. The authors didn't follow the overweight people to see if that 51% stayed healthy or if they developed problems later on; they just took a snapshot of a group of people at one time. Just as these authors are cautioning that correlation does not equal causation, that obesity may be correlated but may not cause health problems, so might they be reaching the wrong conclusion.


I think the heavier you are, the harder it is to be healthy. I can share that I am 5'1" and have weighed as much as 158 lbs, putting me at a BMI of 29.9, which is almost to the obese category. When I couldn't fit into my interview suit from med school to interview for residency, I decided it was time to act, and I hit the gym. I was really appalled at how badly I performed (although I was also having a lot more asthma trouble at that time, too). Still, it's hard to move well with jiggling areas and extra pounds. Every step I took on the treadmill or elliptical, I lifted more weight than a woman my height should (unless she's wearing ankle weights). In other words, my system had to work harder to do the same amount of work as someone with a "normal" weight.

That was around September last year. I worked out and worked out and worked out and eventually noticed I was a little less winded on the elliptical. I'd also lost about 5 lbs, and fit into my interview suit in time, which was my first goal. Over the spring and through my trip to China, I ate a little less, and lost another 5 lbs. This time, I had to buy new pants in a size 10, so now I have a huge motivation not to gain the weight back (if I lose more, I'll have them taken in).

Losing weight is really hard, and I haven't really lost that much. Enough that people noticed; enough that I went down a dress size; enough that my midsection is noticeably smaller (I have an hourglass shape, so most of my weight is on my lower half). I really, really like the way I look now, and I'm having to work hard enough to stay this weight that I'm not sure I'm ready to try to lose more. It's funny, but the first time I weight 148-lbs I felt awful about it. Now, coming down to 148, it feels great. My resting pulse is lower, my blood pressure looks good (it wasn't high, but now it's even better), and my cholesterol looks better (though still a little high).

In other words, if I'm healthy at 148, or a BMI of 28, then that's okay with me. Sure, I'd love to be a size 4, but with the junk I've got in this trunk, it's never going to happen. To get a BMI of 25, back in the "normal" range, I'd have to get down to 132 lbs. I'd really like to get there, but I don't want to end up a yo-yo dieter. I'd rather stay peacefully in one spot than get yanked all over the place. Besides, I really like cookies.

So, I'm really trying to base my personal health assessment on how I feel, what my vitals and cholesterol look like, rather than my BMI. I figure, if I can get on the elliptical for 45 minutes, then walk a mile at a steep incline, and then do a few weights, how bad off can I be? My next goal: to jog a whole mile without stopping or being severely winded. In 26 years, I've never accomplished this; I may never accomplish this, but by god I'm going to try. It would be nice if achieving this goal also got rid of my double chin or made my legs less jiggly, but I'll try not to let that be my only measure of success.

Of course, internship is seriously getting in the way of my personal fitness crusade, but hey, we wouldn't want this to be too easy, now, would we?


The MSILF said...

I'm getting fatter too. I don't care how it looks per se, I think it's womanly, but I hate that my clothes don't fit. Gotta get back exercising. It's so hard during this year though...

Tiny Shrink said...

Yeah, even on easy rotations my hours are unpredictable and it's hard to drag myself to the gym...