On a serious note, don't drink too much caffeine... for me it is a digestive system kick-start, and if I get too much... the less said the better.
As a type II diabetic I'd say the decrease in sugar intake is also a major benefit.
My personal opinion is that the prevalence of HFCS (High Fructose Corn Syrup) in most domestic products is a contributor but some studies (I won't name the funders
) say that the similarity of the curves showing increase in Diabetes cases and increase in HFCS use is purely coincidental.