How many hours and days per week are you going to be at it?
I think you will be hugely busy and frankly i can't see the point in going to the gym when you are already on your feet constantly - if that's indeed what you will be doing. Also in your new stressful situation your brain is going to be working over time you are going to be burning through calories like mad just to keep thinking straight.
So on your days off after you've had a good sleep, then think about going to the gym or something like that. If you find you are getting over stressed with work, then it really is a good time to take up yoga and meditation so that you can do it at home. One or two classes a week should be enough to give you what you need to bring to your job lifestyle. YOU can even do little bits at work to help you stay relaxed.
Try to plan your eating ahead of time so that you aren't caught short and take the nearest thing to eat. If you are going for long periods without food, i know you will want sugar and stuff that you would prefer not to eat. I know you will tend to overeat when you do get the time to eat.
Have a good breakfast before you leave home in the morning or whenever it is you leave home and have a good meal when you knock off. For in between times at work, maybe have some yoghurts on hand, some fruit, some bread, or take some sandwiches. Take two rounds instead of one so that you can quickly get a bit more energy into you without going off the rails. You may not have time to eat it anyway. I'd say you are going to need more calories than usual but don't take that to mean you can eat lots of rich food and large portions. I don't know. I just think that interns can't help but lose weight. Ask some of the other doctors around.
I'll be keep an eye out for you but you will probably be too busy to keep posting regularly won't you.
.... I dunno. I always start my posts with the intention to say just a few words but it always ends up being a chapter.

