MISSISSIPPI STATE -- Believe it or not, junk foods are not a necessary part of young people's daily diets, but neither are they deadly sins.

When given the choice, many students choose candy bars, cookies and soft drinks over salads and fruit. But when this happens regularly, the body's nutritional needs are not met.

Dr. Melissa Mixon, Mississippi State University extension nutrition specialist, said adults, too, are often guilty of choosing empty calories over needed nutrition.

"Junk foods such as chips, candy, soft drinks, cakes and cookies fit best in the top of the food pyramid and should be eaten in the smallest quantities," Mixon said.

Yet the temptation persists to grab a candy bar and call it lunch. This happens often in schools, and some are responding by taking vending machines out or unplugging them at lunch time.

"A good diet, along with proper exercise and sleep, helps students stay alert and focused in class," Mixon said.

Eating breakfast also should not be ignored. Mixon said students who eat any type of breakfast perform better in school, although healthy breakfasts have a greater benefit.

Popular junk foods are high in sugar, fat and calories. They do not fill the body's nutritional needs, and eating them can contribute to the national trend of Americans being overweight.

Junk foods do not make good afternoon snacks. Mixon suggested nutritional foods such as fruit or sandwiches for after school. Not only are these good for the body, but they provide a consistent energy supply, something that junk food does not do.

"Parents should identify different snacks their children are free to eat," Mixon said. "That way youth can choose their snacks, but parents still ensure they eat well."

Proper snacks are good since eating more often, but in smaller quantities keeps the body's metabolism going and the brain alert. As a general rule, students and people of all ages should eat more fruit and vegetables and drink more water.

"There are no such things as junk foods, as all foods have a place in nutritionally-balanced diets," Mixon said. "Students can still eat their favorite snack foods, but these shouldn't replace meals or be eaten in huge quantities."