We take our DC out all the time, but yes, trips out or meals out are viewed as a treat by our family, they are expensive after all and not a necessity.
As such the DC are allowed mostly free reign as to what they eat or drink, but I try and discourage them from fizzy drinks and if we go to pizza hut or somewhere with an icecream machine or salad bar, I always try and make sure they only take what they think they can eat, although I don't mind how much that is. I've never noticed anyone judging me for it though, but I wouldn't care if they did.
My friend is extremely strict with what her DC eat. They are never allowed fizzy drinks, not ever. The DC do have limited diets though as they dislike a lot of things and the other day they were having dinner of white pasta mixed with tuna, sweetcorn and mayo with hot dog sausages and a wrap each. I do find that an odd dinner for someone who is so obsessed with their diets and I wonder if maybe she just isn't very knowledgable about food. They also often eat frozen stuff like pizza, nuggets, chips etc.
Oddly, this friend was never, ever allowed fizzy drinks as a child and now drinks the best part of 4L of diet coke every day. She will not drink anything else at all, ever, no water, no tea or coffee, no fruit juice.