I am starting grad school in the Fall and finding these tips very helpful!
In undergrad, I actually lost some weight that I had gained in my party-hardy Senior year of high school by following a vegan diet. For me it boiled down to eating less processed food, and cooking at home more often, a philosophy I still follow 5 years later, despite the fact that I have chosen to add meat back into my diet. I decided that a 100% vegan lifestyle was too extreme for me, at this point in time, and I was missing out on key nutrients. When I do eat meat, it is something lean like chicken, or a small portion like a few crumbled slices of bacon in an omelet.
Also, I try to stay active as much as possible since I find this leads to an overall increased sense of well-being (as lrlrlrlrlr mentioned, tired/over-caffeinated sedentary co workers). In undergrad I would utilize free street-parking and walk to class since I lived off campus, and I would try to squeeze in a workout between classes or class/work.
I graduated in Dec 2014, and it was not until the past 6 months or so that I really got back into working out. I've had a membership to a certain Judgement Free gym for much of my adult life, and would casually go here and there. However in the past half a year I started working with the personal trainer they have on staff, and I have gained a lot of strength and confidence. I used to run cross country in high school so I have decent endurance and lower body strength, but I have really seen a lot of improvement in my upper body strength and other weak areas. Since my job during Grad school at UM will be at their Fitness center, I hope to continue using the gym to keep my body and mind healthy.
So basically, my little life advice is:
1) Prepare meals at home as often as possible, eat before you go to class or pack breakfast/lunch. I also love my crockpot, so easy to use and hard to screw it up! Haha.
2) Walk rather than drive if possible. This helps with stress too. If I have a big project or exam coming up sometimes I just need to take a break and walk or bike around the neighborhood to clear my head. Yoga is nice for this too.
3) Find a sport or activity that you enjoy. Set goals and achieve them. For me, this was working out 3x/week with the trainer. We started with 30 minute sessions and now its 1 hour, 3x a week. Even though this is not an intense commitment, I have seen my strength improve drastically and am able to motivate myself to go work out even if I am not in the "mood"... once I get in the gym I know I am there to work and generally get a good session in anyway.
Well, hopefully I can stick to my own advice once classes begin! Only time will tell ;-)