October 19, 2009
Moderately Overweight Live Just As Long?
Obesity is still seen as deadly but a body mass index between 25 and 30 might not reduce life expectancy.
Contrary to what was previously assumed, overweight is not increasing the overall death rate in the German population. Matthias Lenz of the Faculty of Mathematics, Computer Science, and Natural Sciences of the University of Hamburg and his co-authors present these and other results in the current issue of Deutsches Ärtzeblatt International (Dtsch Artzebl Int 2009; 106: 641).
Most Germans are overweight, with a body mass index (BMI) between 25 and 29.9 kg/m2. About 20% are obese (BMI of 30 or over), with age- and gender-related differences. The authors systematically evaluated 42 studies of the relationships between weight, life expectancy, and disease.
The Süddeutsche Zeitung published an advance notice of the report (http://www.sueddeutsche.de/gesundheit/140/489526/text/), which shows that overweight does not increase death rates, although obesity does increase them by 20%. As people grow older, obesity makes less and less difference.
Keep in mind if you are gaining weight that even if your BMI is still under 30 you might be on path to a BMI up in the danger zone.
Being overweight does boost heart disease risk. But people who break their hips become less mobile and a lot less healthy. Being overweight trades off between different health risks.
For coronary heart disease, overweight increases risk by about 20% and obesity increases it by about 50%. On the other hand, a larger BMI is associated with a lower risk of bone and hip fracture.
In relation to cancer, the overall death rate among extremely obese men (BMI above 40) is no higher than among those of normal weight. Men who are overweight even have a 7% lower death rate. No significant association was found in women.
What I'm expecting: Genetic testing might show us what our relative risks are for a large variety of diseases and this knowledge could push us toward different ideal weights depending on which diseases we have the greater risks for. Also, some people are probably genetically better adapted to carrying more weight.
Note that you have other options for slowing bone decay aside from carrying more weight around. Exercise, better food, and a combination of vitamin D and vitamin K might cut bone fracture risks with age.
Weight studies are problematic because weight can vary due to muscle mass as well (albeit less often). Also, people can lose weight during the early stages of an illness before they even know they are sick. How well did the researchers adjust for these factors?
The issue is going to come down to *when* your body mass is in the 25-30 range.
As (most) people get older they put on more body fat, so a person in their late 50s is at 25-30 percent is a lot less likely to have issues than someone who is in their late teens and is hitting that line. The numbers I've seen have suggested 3-5 pounds per decade, is 1-2 percent per decade for "normal" people. This means that if you're 20% body fat at 20, by 70 you're borderline obese (maybe, but I think you can see where I'm going).
I also strongly suspect that it takes a LOT less exercise and control to get from "Obese" to "moderately overweight" than it does to get from "Obese" to "The Body Of [Adonis | Venus]", so maybe if people were to adopt more appropriate metrics they'd be more likely to see some success.
Doesn't it depend on visceral vs subcutaneous body fat? I'd read somewhere that the subcutaneous fat has a protective effect or was neutral in re coronary problems.
Let me paraphrase your article: Being moderately overweight doesn't seem to harm your health, but you still shouldn't be overweight.
An easy way to get from slightly overweight (200 lbs for 5'10") to obese (250 lbs) is to have bad knees and chronic pain for several years without realizing you have to severely restrict your diet. 5 lbs per year for 10 years equals that 50 lbs, and believe me, it becomes very hard to take it off. It's much more than reducing your diet for another 10 years--your metabolism has changed, in my case causing metabolic symdrome, etc.
I wish I knew then what I know now. (Of course, this is applicable to SO MANY THINGS in our lives.)
As far as I'm concerned, anyone who tries to claim that there is some ideal BMI that applies to the entire human race is a complete quack. In case I wasn't sufficiently clear, they are utter nutcases (or possibly people with a hidden agenda, though it is difficult to see what that might be). I fully intend to live the rest of my life according to what my body tells me to do. My guess is that 4 million years of evolution trumps a few decades of book knowledge any day. I'm guessing that my point of view will not be popular with your readership, which clearly prefers to suffer and die.
This isn't going to stop any of the weight nannies, because it was never about health or longevity.
The weight nannies are about control.
What about lean muscle mass? I'm 5'11" and 200~ lbs, with low body fat%. I lift weights. Am I fat? Does this study account for men like me with muscle? BMI is a terrible measurement of body fat.
There is no excuse to be fat, ever, its just that people are lazy today.
Do I want the government to impose those changes? No.
I also don't want to pay for healthcare of people who are fat lazy slobs either. This is even one more reason to be against single-payer gov't healthcare; I pay the same in taxes as someone that doesn't eat right and leads a sedentary lifestyle.