So you can imagine my surprise when a systematic review of 97 studies involving close to 3 million participants was published last week in JAMA in which the authors concluded that being overweight BMI was associated w/statistically significant 6% lower risk of all-cause mortality compared to normal BMI. As expected, overall obese BMI was associated w/higher all-cause mortality, especially w/BMI >35kg/m2. But even mild obesity w/BMI 30-35kg/m2 was not associated w/any different mortality compared to normal BMI. This had to be a fluke, right?
Wrong! It turns out that I had in my flash drive a study published early online in August 2009 (and finally in print in February 2010) in Obesity Journal in which the authors concluded that both overweight & mild obesity were not linked to an increase in years-of-life-lost compared to normal weight.
Well, this may be true but I'm still not totally convinced that being overweight or even mildly obese is better for you than being normal weight w/reasonable body composition. In fact, an August 2009 study published in the International Journal of Obesity concluded that being overweight in middle age increased one's risk of dementia later on.
So does that mean I'm going to live longer but w/dementia if I don't normalize my weight now? If that's a consequence of overweight being the new optimal, I'll pass.