It appears that overeating is really the reason people go on cruises. At meal after meal on our cruise ship, it looked as if we had missed the announcement that those who didn't eat their weight in appetizers would be off loaded to Camp X-Ray. And that was just our family.
Seriously, you can eat as much as you want and you can eat 24 hours a day. Here's the skinny:
There are three main meals on the cruise ship, and each is offered in either a serve yourself cafeteria setting(s) or in a sit down dining room. The food's basically the same if not identical, so it is your call about whether struggling with trays or avoiding sketching out the map of Albania in juice stains on table clothes is your preference with kids.
The cafeteria is easy for a family because you and the kids can see what you are choosing, and can ladle out portions sized for Homer or for Maggie. The tray rail is kind of high, so little kids might need a boost which means you'll have to slide the tray with your navel (if an outie). There are staff around to answer questions, though they were stumped by queries about peanuts and MSG (though went for answers right away). Our kids liked picking out their food and sampling a little of everything. At times they overloaded their trays and with drinks it all got hard to balance. We made a lot of return trips for ketchup, rolls and seconds. We sort of acted like pigs I guess but it seemed OK.
Being served in the dining areas was also cool, as the wait staff works in large part for tips and always made a fuss over the kiddies (I guess it was the tips ‘cause we just aren't that interesting to hang with otherwise). Everybody got water upon sitting down, and within seconds crayons and color-on-me kid menus appeared. The waiters always asked if we wanted the kids served first or with our meals. We saw some waiters make funny animals out of folded napkins. The kids' menu has the old favorites of mac and cheese, hamburgers, chicken fingers and fish sticks-short on veggies and non-fried things. The grownup menu was set each day with three or four main entrees, and our older child was allowed to mix things from the kid menu and the adult menu (and at 12 years old the indecision about whether she is a kid or not still is what it was all about). As a parent you'll want to watch out for lots of glassware and multiple forks on the table, cloth napkins and table cloths and all that kinda bump and run away fun.
The potential for junk food on the cruise ship was set at Defcon 5 the whole trip. On our ship an ice cream machine was on public display and all-access most daylight hours, and pizza and hot dogs were served continuously near the pool. Anyone could order complimentary room service, to include sweets, and no one seemed to care if the ordering voice requesting a bucket o' fruit cocktail was 8 or 43 years old. If you are watching what your kids eat, or how much, be prepared to stay active.
There was no special infant/baby food available, and none sold in the on-board ship stores. However, it would have been a no-brainer to get a bottle warmed up or something heated, mashed or modified at the sit-down meals.