I've just finished re-reading one of my books, "Mastering Leptin" which further implicates the dangers of gastric bypass.

Apparently the surgery reduces the amount of functional stomach, thereby dramatically lowering the levels of ghrelin. Although this initially seems like a good thing, ghrelin is the key signal in the body that enables the proper release of growth hormone. So without proper ghrelin function, aging worsens as the body cannot correctly repair itself.

Here's a link to an article: Deaths Raise Fears Over Stomach Stapling

Wanda