FDA AdCom Strongly Supports Abandoning Excess Weight Loss

Relative Size Illusion

Regular readers may recall previous posts on the widespread reporting of weight loss in surgical studies as ‘excess weight loss’ – a meaningless number based on outdated concepts of ‘ideal weight’. In fact, not only is there is little correlation between the amount of weight lost and improvements in post-surgical morbidity and mortality but there is nothing to suggest that using this measure does anything more than amplify the numbers – after all a rather remarkable 60% EWL is little more than 20% of initial weight – but of course 60% sounds so much better.

I was therefore happy to see that last week, at the FDA hearing on obesity devices, according to Close Concerns:

“There was nearly unanimous support for using percentage of total body weight rather than percentage of excess weight loss as a study endpoint. Panelists cited the “significant flaws” in excess weight loss, especially the challenge of applying it to individuals with lower BMIs. In contrast, many believed that using percentage of total body weight loss provided a more valid metric for people at both high and low BMIs.”

Hopefully, surgeons and surgical device makers will take note and comply with what I am hoping the FDA will from now on like to see in all future submissions – strict reporting of percentage of ‘total weight loss’ rather than the confusing, arbitrary, and scientifically unsound use of ‘excess weight loss’, which I fear the surgeons may find hard to abandon.

AMS
Brooks, Alberta