Have been on many cruises, eat sensible, do not drink fruity drinks stick to wine, if you want a drink. I usually have a few glasses of wine an evening, one dessert, and no bread or butter with dinner. Usually gain a pound or two. Could leave out wine and dessert, but it is a vacation. I also always take the stairs, walk 30 min in the morning and 30 min in the evening, and dance instead of sitting in shows.