A grumbling stomach and slight abdominal discomfort ("hunger pangs") are the most common first signs of hungry. Go without eating for a bit longer, and you may start feeling grumpy, shaky, and become unable to concentrate. It's common enough, that's for sure — type "when I'm hungry I" into Google, and "feel nauseous" automatically emerges as a suggestion.
While that statement is hardly worth as much as a scientific study probing into the percentages of people who feel sick to their stomach when they're hungry, the fact remains that Google doesn't offer those autofill suggestions if only two or three people a month use that search term.