Hey - hiccups are funny and almost anything can set them off. Water fasting has been known to as well. They're nothing to worry about unless they get so frequent or intense they're causing you trouble drinking / sleeping. It's likely that your sudden diet change caused them either by upsetting your system or introducing more air into your stomach. If they keep on going, get them checked out... What Causes Hiccups and Chronic Hiccups for more info... Good luck!