Hunching over a computer keyboard all day can strain your wrists, eyes, neck, and back. Take a timeout every half-hour to stretch, walk around, breathe deeply for 5 minutes, or otherwise move away from the screen.
Eat Some Greens
Fruits and veggies give you nutrients that help keep infection and disease at bay, so put plenty on your plate, Rosenthal says. A simple rule is to fill half your plate with fruits and vegetables. Most college dining services offer salads and other greens. Mix it up: spinach salad one day, mixed greens the next.
Fight the Flu
Get a flu shot every year. The vaccine is usually available by early October, though you can benefit from a vaccination as late as early December, when there are still several months left in the flu season. This is especially important for college students who are in close quarters with roomies and classmates. Many colleges offer flu shots for free or for a small charge that's typically covered by insurance.
Chug Some Water
Drink plenty of (non-alcoholic) liquids each day, Rosenthal says -- more if you exercise or tend to perspire a lot. Dehydration can make you more vulnerable to illness and infections. By the time you notice you're thirsty, you're probably already dehydrated, so don't get to that point. How much water is enough? If your urine is light yellow, you're well-hydrated. If H2O isn't your thing, don't worry -- juice, tea, and other beverages count as well.
Back Off the Drinks
Drinking too much puts you at risk for accidents, injuries, and regrettable behaviors, not to mention a host of serious conditions from high blood pressure and liver disease to cancer. Stick to the recommended daily limit: no more than two beers or glasses of wine for men, and one for women.
Find Your BFFs
Having someone you can talk to and count on is important for your mental health, and the right friends will encourage healthy habits. Seek out campus groups, play a sport, get to know your dorm mates, and put yourself out there to attract friends who will support you.