Accurate waist measurement

The heart and stroke foundation on their website www.heartandstroke.ca gives directions of how to take a proper waist measurement. Basically the measurement is done with the individual in the standing position after breathing out and with the stomach relaxed. The website also includes a short video illustrating this methodology. But is this an accurate measurement of a persons waistline?

People with poor abdominal muscle development and/or muscle tone, as well as others with the "gravity effect " from a redundant transverse colon and/or an enlarged liver are 3 conditions which could give a false high measurement. Taking the measurements in the supine position should eliminate some of these "false " high readings. I compared these 2 methods of measurement on myself and found that in the standing position my waist measured 84 cm (33in) but only 77 cm (just over 30in) in the prone position - a difference of 7 cm or almost 3 inches!

I also noticed that my abdomen had that cave in profile (scaphoid profile) reminiscent of the greyhound and postulated that this was probably the cause for this difference.

I should mention that in my clinical practice days while examining patients not for their waist measurement but for abdominal pathology (masses), I found that very few of my "obese" patients showed this scaphoid profile. Could this difference be correlated to the amount of "internal" fat deposits they possessed, especially around their colon? Maybe this could be the major risk factor for cardiovascular disease and not their waist measurement?

Until large population studies are done using both methods for waist measurement conclusions cannot be drawn. It does seem that we need a more accurate non-invasive measurement for internal fat deposits. If not, the total answer combining these 2 methods may give some indication of the amounts of internal fat deposits. This in turn could be shown to be the risk factor and not waist measurement.