Hi, I'm a new member (23-m) and a graduate student about to complete my studies after this summer. I know how hard it is to balance healthy living and studying, but it is possible. I've lost 35 pounds over the past 14 weeks through an entire lifestyle change.
You must get away from the computer and exercise for at least 30 minutes a day to really make a difference. I bought an exercise bike ($100) that I use for 45 minutes 7 days a week to get my aerobic exercise. I do most of my work from my apartment, so it is very convenient. Hopefully you aren't stranded in a dorm & you have room for some indoor equipment. The other part of exercise is doing weight training. I do a 30 minute session 6 days a week using only dumbbells and flat bench in my apartment. You can work out any muscle group with this simple equipment. And ladies, you must weight train as well if you want to make serious dents in your weight- no sissy weights either. You should be reaching muscular failure after 6-15 reps on one exercise. Here's a great link with descriptions/pictures/videos of dumbbell exercises for each muscle group (it's free of course)-
Dumbbell Exercises
Keeping up with your exercise will keep your mind sharp and reduce your need for all those sugary caffeine drinks. I promise.
If your school is anything like mine, few healthy foods are available. When I eat at the cafeteria- I go straight for the deli & eat a turkey on wheat with lots of veggies and a small amount of dressing. Throw in a piece of fruit, too. Basically all the other foods available at my school are fried/fatty/calorie-filled garbage. One other thing- drink 2 liters of water a day. No exceptions. You can do it, just hang in there.