**Adding This: Try Hula-Hooping! It's REAL fun, a cardio work out, and gets you sweaty and tired & toned up! I do that, and it's real great, it works out the ENTIRE body... just do it to music, or while watching TV. All you need is a hula-hoop! Real easy and a no-brainer!
Try and reduce the "starches" in your daily eating.
I don't mean all 'carbs', just starches... ie: white rice, white bread, pasta (unless whole wheat), potatoes.
Starches are 'simple carbs' and just digest into sugars.
Versus, "complex carbs" like whole grains, veggies, whole grain breads, brown rice, etc. are processed differently in the body.
I have friends, that simply cut out or reduced the amount of white rice and white bread/pasta they ate, and they lost weight. It is a more 'sane' and slower weight loss, which is healthy.
Also, just try and walk anywhere you can. Do the stairs at buildings, when you are home and watching tv or something, just do squats or lunges at the same time. Or, jog in place. Or, get light hand-weights and do that while you are watching tv or something. (I know, you're busy and probably don't have time to just 'sit' for tv... but anytime you have a moment... even just 10 minutes... can really help). Also, 'resistance' or weight bearing exercises helps by building up lean muscle mass, which in turn is more efficient at burning calories and fat.
Or in between studying, even if for 10-15 minutes... stand up, do squats, push ups, sit ups, etc. And this will help too.
It's not just about "calories." Its about what you eat. In balance and moderation. Also, drink lots of water. Or try eating smaller portions.
All the best, hope this helps,
Susan