Children's extracurricular activities and parents' long workdays are starving the time-honored tradition of family dinners.

Although 78 percent of parents said they think eating dinner together as a family is important, 55 percent said they are able to spend dinner together only four times or less each week, according to a recent survey conducted by Opinion Research Corp.

Parents working late was the biggest barrier, according to 34 percent; extracurricular activities, the second at 28 percent; and parents working opposite work schedules, 21 percent.

Respondents cited no time to cook and picky eaters as two top challenges to family dinner.

The National Center on Addiction and Substance Abuse at Columbia University recently polled 1,987 teenagers and 504 parents of teens in households nationwide. Key findings:

• Teenagers who have dinner with their family five or more times a week were almost twice as likely to earn A's in school than teens who have family dinners two or fewer times a week.
• Teenagers who have frequent family dinners are less likely to have high stress levels.
• Teenagers who have family dinners two nights a week or less are twice as likely to abuse illegal substances as are teens who have frequent family dinners.