Can I chew gum during ProLon®? 22 February 2022 01:30 Although we suggest no additions to the program, up to two pieces of sugar-free gum per day is allowed. Related articles If all of the food designated for one day is not eaten, can it be eaten on the next day? What if food outside of the ProLon® program were eaten during a day of the diet because of circumstances (e.g., social event)? Is there a "transition day" diet after completing five days of ProLon®? Can I switch the boxes’ order? Is tea, coffee or infusion allowed during ProLon?