The FastDay Forum

This link, referenced elsewhere, may benefit a broader audience:

http://healthland.time.com/2010/12/03/w ... longevity/

The main points being:

"The National Institutes of Health (NIH), which funded the study, reports:

Healthy women who had never smoked and who were overweight were 13 percent more likely to die during the study follow-up period than those with a BMI between 22.5 and 24.9. Women categorized as obese or severely obese had a dramatically higher risk of death. As compared with a BMI of 22.5 to 24.9, the researchers report a 44 percent increase in risk of death for participants with a BMI of 30.0 to 34.9; an 88 percent increase in risk for those with a BMI of 35.0 to 39.9; and a 2.5 times (250 percent) higher risk of death for participants whose BMI was 40.0 to 49.9. Results were broadly similar for men. Overall for men and women combined, for every five unit increase in BMI, the researchers observed a 31 percent increase in risk of death.

...

What about those at the low end of normal BMI? A healthy BMI ranges as low as 18.5, but longevity was associated with a minimum BMI of 20 in this study. “For women in the BMI category of 15 to 18.5 we observed the increased risk of death was 47%, and for women in the BMI category of 18.5 to 20 the increased risk of death was 14% compared to those in the BMI range of 22.5 to 24.9 (our reference group),” said the study’s lead researcher, Dr. Amy Berrington de Gonzalez of the National Cancer Institute."

[carorees]

The "ideal" BMI is slightly different depending on whether you want to live a long time or have lower disease burden (morbidity). I think I'd rather have quality of life than quantity of life! The thread on target setting has pretty much covered the info on morbidity...it seems that a BMI of about 22 is best. Another thing that I've posted about is that BMI trajectory (i.e. whether you're losing weight, gaining or stable) is possibly more important than your actual BMI, so that it's better to be stable than yoyoing. This is why I emphasize that finding a sustainable WOE is better than struggling to hit a particular weight but not be able to maintain it due to too much restriction.

I personally think looking at just BMI as far as longevity is a little like looking at the sugar content of food but ignoring other things in the food like fats or protein etc..

Its so easy to get caught up on just a single metric but sadly health is much more intricate than that.

I think you are better to aim for a healthy BMI but also look at many other areas too. Its quite possible to have a healthy BMI and be a very unhealthy person.