All-you-can-eat dining, late-night pizza runs and high-calorie caffeine drinks are just some of the diet challenges many college students face as they begin the school year.

For some, the change in eating habits can lead to weight gain the first year of school.

Researchers at the University of Guelph, Ontario, found that the average weight gain among 116 first-year female students was about five pounds. The researchers noted that the increase was over six to seven months, and warned that continuing at that rate could lead to being overweight or obese.

Results from two studies published in 2006 found that the average weight gain among freshmen was five to seven pounds, followed by a two- or three-pound gain their sophomore year.

For many, maintaining a healthy weight takes a conscious effort to keep track of what they're eating and finding different ways to integrate physical activity into their daily routine, say health professionals, college students and recent college graduates.

Calla Whipp found that staying active and eating in moderation has helped her keep her weight fairly stable while attending Drake University.

The 21-year-old senior ticked off all the activities she enjoys — step aerobics (she teaches at Drake), dancing, biking, running, walking with friends and riding horses.

It helps to pick a workout schedule you can sustain and find a friend to work out with, says Whipp. She's also taken the advice of her mother, a health teacher and aerobics instructor, when it comes to food.

"You can eat something bad every once in a while," Whipp says. "My mom has always said, 'Everything in moderation,' and I think she's right about that."

Some tips to keep weight in check:

Eat breakfast: It's true, breakfast eaters tend to perform better on tests and eat fewer calories in the evening and do less binge eating at night. Try eating half a peanut butter sandwich, fresh fruit, yogurt, a glass of milk or breakfast bars that are low in sugar and high in protein and fiber — you'll feel full longer than if you scarf a doughnut.

Eat your vegetables: And fruits, too, raw or cooked.

Focus on your food: Sit at a table to eat your meal. It should take about 20 to 25 minutes. If you can't do this every day, pick one day out of the week to start.

Hit the student health center for advice: At Iowa State University, students can get tips for free from fitness and nutrition specialists at the student health center. Colleges generally offer those types of services, nutrition therapist Judy Trumpy says.

Eat the "good" fats: Healthful fats in moderation — including those found in peanut butter, nuts, fatty fish and oil — help you feel full too, and prevent cravings between meals.

Go ahead and snack: But make it small and sensible. Try to eat about every three hours. Some options are three to five whole grain crackers, yogurt, an apple or carton of chocolate milk.

Drink up: Carry a water bottle to help you stay hydrated. Drinks like coffee, tea and milk count toward your daily fluid requirement, as do fruits and vegetables with high water content — melons, lettuce, oranges, green beans and red peppers. But avoid calorie-laden alcoholic drinks.

Don't pig out in the dining hall: Eat slowly. Wait 10 minutes, gauge whether you're full, then decide if you want seconds.

Get your sleep: If you're rested, you'll be better able to fight the stress that can prompt overeating. To sleep better, avoid eating, exercise and caffeine after mid-evening.

Sources: Judy Trumpy, nutrition therapist at Iowa State University's Thielen Student Health Center; www.kidshealth.org