I don't eat a lot of ice cream anymore (except a little during the summer, hand made one is crazy good). But when I was a teenager, there was a winter where they were selling a 4l of Rolo ice cream and I was eating it in like 2 days. I don't know how my body could consume all of it. Let's say I was not watching my weight at that age (and didn't need to). Not the same today. I would be ill for a week if I ate the same way I did, and I still eat a lot (got to maintain some reputation).