August 16 (HealthDay News) -- Irresponsible eating, lack of exercise and alcohol consumption are among the factors that contribute to the Freshman 15, which refers to the extra pounds packed on by many new college students, according to a Duke University expert.

Many freshmen don't know how to select or make healthy meals, and stress from heavy class loads and the struggle to achieve good grades can make them eat food at the wrong time, said Elisabetta Politi, nutrition director at the Duke Diet and Fitness Center. Processed convenience foods are an easy option when students are up late cramming for tests or finishing papers.

Campus gatherings often include alcohol, which has a lot of calories. But it affects weight in other ways, too.

"When you drink alcohol, your resistance to everything goes down, including your resistance to temptation of fatty foods. You tend to eat more when you drink," Politi said in a Duke news release.

She also noted that many students who are physically active in high school become couch potatoes when they start college.

Politi offered a number of tips to help new college students keep their weight under control:

• Make a plan. Know when your classes are and plan how to eat healthy between classes and where to get appropriate foods.
• Eat breakfast. If you're in a hurry, keep it simple by choosing whole grain cereal with milk and a piece of fruit.
• Have a good supply of fruits and vegetables so you have something healthy to eat when you need a snack.
• When it comes to beverages, drink lots of water, choose sugar-free drinks, and have a few glasses of low-fat or fat-free milk each day. The protein in milk can help you feel full longer.
• Use the "plate your portion" strategy to maintain portion control. Fill half your plate with vegetables and fruit, one-quarter with grains (possibly whole grains), and one-quarter with lean protein. Avoid mayonnaise-heavy side dishes such as coleslaw, potato salad and macaroni salad.
• Keep a food diary, which will help you assess and change your eating habits.
• Get at least 30 minutes of physical activity a day.

SOURCE: Duke University, news release, July 25, 2008