If you are over 50 it’s healthier to be overweight than not

Seriously folks, the lowest mortality rates over 50 occur in people currently defined as overweight. This is not theory, but data based on millions of people (see later).

So how does medicine define who is overweight?  By the Body Mass Index (BMI) being over 25 and under 30.  Obesity is defined as a BMI over 30.

Saying that someone over 50 with a BMI between 25 and 30 is overweight is true by medical definition, but that doesn’t make being overweight unhealthy (which is of course the implication of the term).

Well medically, you can define words any way you want, but Abraham Lincoln had it right

” How many legs does a dog have if you call his tail a leg?

Four.

Saying that a tail is a leg doesn’t make it a leg.”

 

If you’re itching to find out what your BMI is, the following site works for meters and kilograms or pounds, feet and inches — https://bmicalculator.mes.fm/?gclid=CM66rIG2tc0CFYQ2gQodOdINEg.

Here is where you can read the paper summarizing data on nearly 3 million people– https://jamanetwork.com/journals/jama/fullarticle/1555137?__rtqa=f4c5e818aba04f769cfc65207b2199b9

It’s better to read the following article in Nature.  It actually includes  the mortality curves at different ages which you can inspect at your leisure —

http://www.nature.com/news/the-big-fat-truth-1.13039

The only thing I don’t like about the BMI vs. mortality diagram, is that it is rather compressed, with data from BMI’s ranging from 15 to 45.  So the overweight range (25 – 30) doesn’t take up much space.  But look carefully at the overweight range — the curve is pretty flat here regardless of age showing that it really doesn’t matter how overweight you are (as long as you’re not obese, or superskinny).

Naturally this did not sit well people who’d staked their research careers on telling people to lose weight. One study by a Harvard guy removed 900,000 people from the JAMA study.    Robert Eckel, an endocrinologist at University of Colorado in Denver made the great comment that  “It’s hard to argue with data. We’re scientists. We pay attention to data, we don’t try to un-explain them.”

Now here is an explanation which I’ve not seen elsewhere so it might be original.

The BMI is far from perfect, but to calculate it all you need are two simple measurements that anyone can make — height and weight. It doesn’t rely on what people remember (how much they usually eat, what they weighed in the past.   However the calculation of BMI is not a simple ratio of weight divided by height but weight divided by height squared.

People lose height as they age, so the BMI is quite sensitive to it (remember the denominator has height squared). As a high school basketball player my height was 6′ 1”+, (at age 75) it was 6’0″ (God knows what it is now). So even with constant weight my BMI goes up.

It is now time to do the calculation to see what a fairly common shrinkage from 73.5 inches to 72 would to to the BMI (at a constant weight). Surprisingly it is not trivial — (72/73.5) * (72/73.5) = .9596. So the divisor is 4% less meaning the BMI is 4% more, which is almost exactly what the low point on the curve does with each passing decade after 50 ! ! !

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