Looking around at all the fat people that are old, I sometimes wonder what happened to their skinny friends. Asking one particularly witty rotund elder, I was advised that “all the healthy seniors died.”

I’ve always thought the ideal height and weight charts were off by dozens of pounds. Often people forgot to add an inch to their height if using some charts (like the Metropolitan Life charts, that assume you’re wearing 1″ heels).

Realizing the limitations of these charts, one of the more recent ways to estimate ideal weights is to us the “Body Mass Index” or BMI. This is calculated by dividing the weight in kilograms by the square of the height of the individual in meters. I’m now at 220 pounds on my 5′ 10″ frame. The easiest way to make the calculation is to do the hardest part first … convert your height into inches and then multiply by .0254, and then multiply that result by itself to square it.

That 3.17 is a number that won’t change, unless I start shrinking. So now I can see what my BMI is by dividing my weight in kilograms by that 3.17. So there’s one more pesky conversion to do.

The standard: a BMI of 18.5 to 24.9 is “healthy”, 25 to 29.9 is “overweight”, 30 and above is “obese” and above 35 is “extremely obese”. I moved down from that “extremely obese” level over the past few months to the “obese” level, and I’m very close to being just “overweight”.

But what does this mean? We would assume that “healthy” people would live longer, but as it turns out, several studies are showing that they die sooner. Dr. Biffa’s blog recaps the results of two recent studies that show surprising results:

Compared to individuals in the ‘healthy’ category (BMI 18.8-24.9), overall risk of death for the other categories was as follows:

• Underweight (BMI <18.5): 73 per cent increased risk of death
• Overweight (BMI 25.0-29.9): 17 per cent reduced risk of death
• Obese (BMI 30.0-34.9): No statistically significant difference in risk of death
• Extremely obese (BMI 35 or more): 36 per cent increased risk of death

Here, again, we find that the lowest risk of death was found individuals classified as ‘overweight’. And this result was statistically significant. Perhaps even more surprising than this, though, is the finding that being ‘obese’ did not appear to put individuals at a significantly increased risk of death.

Dr. Biffa makes the point that we should probably move the classifications a bit, so that “overweight” is the new “healthy” category.

But then, my old fat friend couldn’t tell me that all the healthy ones died.

3 Responses to “Does Being Overweight Harm Your Health?”

1. Low Carb Age » Another Study: Low Fat / High Carb Dangerous says:

   July 20, 2009 at 9:28 am

   [...] healthier before the study started. Even with a BMI much higher; mortality studies show that it is better to have an “overweight” than “healthy” BMI. Even an “obese” BMI puts you at parity with the so-called “healthy” [...]
2. Low Carb Age » Obesity: Can you be too thin? says:

   September 15, 2009 at 10:47 am

   [...] studies alluded to in my post “Does Being Overweight Harm Your Health” have been linked on our Obesity research [...]
3. Low Carb Age » BMI and the “Obesity Epidemic” says:

   November 24, 2009 at 11:33 am

   [...] we noted in our post Does Being Overweight Harm Your Health, all-cause mortality studies show that you have a 17% less chance of dying if you are in the [...]