I just wanted to add my support. I work in a doctor's office (psychiatrist/psychologists) and have exactly the same kind of schedule you do. I am the only employee. Regardless of what the law might say about breaks, they are not built in to everybody's schedule. I have to time my bathroom breaks to when no patients are checking in or out and hope that the phone doesn't ring while I'm gone.
BUT...it is possible for me to eat a large, yet healthy, breakfast at 6:30 and last until my lunch at 12:30. And ditto for the afternoon stretch. My meals might be larger than someone who's eating 2-3 snacks a day, but I just do 3 meals a day and, for the most part, I omit the snacks. Sometimes I will carry a baggie with one serving of raw, unsalted almonds in case I get hungry before the end of the day, because I can have a few of those kind of "on the sly," and they really help stave off hunger. Keep your food healthy, don't skimp on protein, fiber, and healthy fat at mealtimes, and stay within your calorie range, and you'll still lose.