Obesity - staggering statistics

I'm at a lecture today about obesity surgery.  The statistics are staggering - 40% of the adults are overweight, trending now to 50%.
http://www.biostat.mcg.edu/Seminars/Year2007/Handout2.pdf

Gastric bypass surgery - after 10 years, people only have lost 20% of their weight.
However, their risk of dying is lowered by 40% due in large part to reduction in prevalence of diabetes and heart disease.

Banding – 10% weight loss retained at 10 years,

Gastric bypass 20% at 10 years (Swedish Obesity Study) NEJM 2007

http://www.nejm.org/doi/full/10.1056/NEJMoa035622

look at figure 1 in the margin.

40% decrease in morbidity

http://criticalcareminutes.com/Resources/Articles/Gastric%20Bypass%20Surgery1.pdf