I am not disagreeing about your medical construct, but as I already wrote Susan, we don't have his medical bulletin and hard data, after 30 years of experience as a physician - I had to disappoint most of my overweight patients in the non diagnosing of disease as such which caused their obesity and that their did not exist a wonder pill to loose weight, in the majority of cases it was too much calories and too less activity.
One would also see about his brothers - if they all ended in the same shape as Boney or not.
From my limited perspective the most plausible case of the heavy weight of the ex French emperor is too many calories.