If you want to get full and true results from the Master Cleanse, you should go by the book, at least for your first go-round. Per Burroughs, only the lemonade drink and water are to be ingested while on the cleanse, along with the SWF (Salt-Water-Flush) in the morning and laxative tea at night to help process eliminations.
Hunger pangs generally only last 1-3 days on the cleanse. Having vegetable broth will stimulate your digestive system and not only lessen the effects of the cleanse (lessen, not necessarily negate), but keep the hunger pangs coming.
Wishing you all the best on your cleansing journey,
d- (just finished Master Cleanse #11)