The ‘obesity paradox’ is the observation that in some disease obese have a lower mortality than people who are of normal weight after the disease has actually developed. One example of this are the studies showing how obese heart failure patients have a lower mortality than heart failure patients with normal or subnormal BMIs.

It’s called the obesity paradox and you can read about it here.

A study just published in Intensive Care Medicine confirms the observation. This time they looked at a general population of surgical ICU patients. The results tell us that over-weight patients, despite being harder to treat and nurse, despite having a higher frequency of complications, have a mortality that is lower than the normal weight population.

In the study, 10.000 patients were divided into subgroups based on their BMS. Then authors looked at their 60 day inhospital mortality. Here are the numbers for mortality,

Underweight  16,1%
Normal BMI  10,7%
Overweight    9,0%
Obese              8,7%
Very obese     13,1%

Their hazard ratio diagram looks like this.










It’s important to realize that they were looking at a large unsorted general ICU patient group. If one would look closer at some of the subgroups there obviously woulnd’t be a an obesity paradox effect to speak of. For example, obese trauma patients are seven times more likely to die of their injuries than patients that are of normal weight.

Abstract can be found here.

Update 10th Feb 2013: New meta-analysis adds further confirmation to this phenomenon:



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