Acarbose blocks starch (and sucrose, to some extent) absorption. Instead of oily poop you get gas that hopefully goes down over time. Starch & sucrose is not as big a part of American caloric intake as fat, but it can still help a bit.

(Just sucrose. HFCS has glucose and fructose, which means sucrase doesn't need to work. Not a meaningful difference in most people considering how fast sucrase works, but when you block sucrase...)