Well, a normal day of food for me is 3/4 C overnight oatmeal (cocoa banana flavored)
Lunch is usually a chicken and Swiss wrap (low carb tortilla). Snack is 1/2 C yogurt, 1/2 C berries 1/4 C cereal for crunch. 2nd snack is cottage cheese or hummus. Dinner is much more varied, as my NY resolution was to try 1 new recipe a week. I can eat about 3oz of protein and some veg. If it's stew, soup or casserole style, I can eat about a cup. Which is actually suggested serving size for adults.
That being said, I just got back from a trip to Paris. I ate a croissant every morning, shared a baguette sandwich every afternoon and stopped for a sinfully rich desert every night. I also walked 10 miles a day, LITERALLY, and came home weighing the same. So you know I ate a lot!!!
You will have to make healthy choices the majority of the time, but you will be able to splurge on occasion. Even at home, I hit the local ice cream parlor about once a month.
The point is, I am not doing without. And you won't have to either. You just can't eat everything bad for you all the time.