is college the reason I am losing weight?

I am male 6 foot 1, 160 pounds. I don't know if that's considered underweight but I really think im skinny and I let it get to me and it makes me feel nervous and anxiety and whatnot, anyways it seems like whenever I start college I lose a couple of pounds and no matter what I do, I can;t gain it back. Then when summer comes I'll gain 3-5 more pounds. i don't know why it is because I'm not doing anything different. I'm eating the same if not more but I wonder if it might be stress? I've tried taking natural supplements that reduce anxiety and stress and it helps to an extent but I feel stressed and weighed down by all the homework and studying and going from class to class. what do you think and what can I do to solve it?

Tips on How to Lose Weight Fast for the New Year

Recommanded Answer:
Many people lose weight because of stress and that seems to be the case with you. Then when you aer on vacation from college you are less stressed and can gain the weight back. Maybe start a strength training/weight lifting routine. If you don't have access to a gym check here for strength training exercises you can do at home. Strength training/weight lifting is really helpful for a whole variety of reasons, including long term weight control, for building muscle, for toning, for improving appearance and posture, and for boosting your metabolism.

http://exercise.about.com/od/abs/ss/abexercises.htm
http://www.wikihow.com/Build-Muscle-Doing-Push-Ups
http://www.moneycrashers.com/strength-training-exercises-women/
http://www.fitday.com/fitness-articles/fitness/exercises/no-equipment-strength-training-with-common-household-items.html#b
http://www.livestrong.com/home-exercises-weights/
http://www.3fatchicks.com/8-household-objects-that-work-as-weights/
http://weightloss.about.com/cs/fitness/a/aa011503a.htm
http://exercise.about.com/od/abs/ss/abexercises.htm
http://www.dummies.com/how-to/content/how-to-strengthen-chest-muscles-with-wall-pushups.html
http://www.muscleandstrength.com/workouts/12-week-beginners-training-routine.html