Welcome back Shayne. I was beginning to think we'd lost you. Glad you are haven't given up.
My weight has been bouncing around the 63kg turning point for a couple of weeks too now. I don't think its because i am not eating enough. I think its more that now i need to reduce a little.
But i don't know what you've been eating or how much energy you are burning through activity so I wouldn't like to say precisely what you should do with regard to calorie consumption.
However, given your stressful and busy times, I think you should make regular nutritious satisfying meals your main focus and let the weight take care of itself. Just do some exercise when you can fit it in. Be strong in resisting the snacks that people offer and as PBL says, keep the stuff out of your house and out of view.
I think if you get into a thing of eating tiny unsatisfying meals, you are risking binges, snacking on bad things, more stress and getting rundown and ultimately, more weight gain. Try to get the habit of good food going. Go for slow slow weight loss as really, surely your studies are the main priority in your life right now. You must know that lots of med students come unstuck during this stage of their careers. I don't know what its like in your country but in places like the UK and even here in Australia, interns and registrars are under a lot of stress and they have to be able to show they can cope, so being healthy is key.
I'd really like to know which country you are in. Is it Singapore? I am such geophile. I just love travel and all things foreign.