Check out this article – Family Meals May Lower Girls’ Eating Disorder Risk. Here are some quotes:
Dr. Dianne Neumark-Sztainer and colleagues from the University of Minnesota in Minneapolis found that adolescent girls who ate five or more meals each week with their families were approximately one third less likely to engage in extreme weight control behaviors, such as making themselves vomit, taking diet pills and abusing diuretics or laxatives than girls who ate less frequently with their families.
However, the researchers found that boys who ate with their families more often were actually at increased risk of unhealthy weight control behaviors. They speculate that boys who eat regularly with their families may have certain characteristics that predispose them to unhealthy eating habits, or that eating with family somehow benefits girls more than it does boys.