Most significantly, when children grow up in families with bad eating habits and sedentary lifestyles dominated by television watching and video games, they are 33.3 percent more likely to become overweight or obese as young adults.
Bad eating habits include no parental control over diet and skipping breakfast.
These findings are among others revealed by a new Arizona State University study on the influence of family environment on adolescent risk for obesity. The study was presented Aug. 14 at the American Sociological Association annual meeting in Philadelphia, Penn.
"Breakfast is the most important meal of the day for weight control," says author Ashley Fenzl Crossman, graduate teaching assistant in ASU's Department of Sociology. "And the amount of time spent in sedentary activities is a strong predictor of weight gain. No surprise."
However, a key finding from the study is that kids don't need to engage in high levels of physical activity to prevent obesity. Instead, adolescents who have less time to engage in sedentary activities because they are involved in other things -- including non-athletic activities such as school clubs, marching band, part-time jobs, volunteer work, church activities or household chores -- are less likely to become overweight.
Crossman utilized data from the National Longitudinal Study of Adolescent Health, a school-based tool designed to assess the health of adolescents in grades 7 through 12. The study population includes a representative sample of all public and private schools in the United States.
Approximately 6,400 children where selected from two waves of the study that took place six years apart, in 1995 and again in 2001-2002.
In addition to poor diet and a sedentary lifestyle, Crossman's study revealed other ways in which parents influence their children's chances of becoming overweight.
Adolescents are more likely to become overweight if their parents are obese. Crossman says that future research should be done with adopted adolescents to determine what may be genetic or environmental influences within families that have an obese mother or father.
High self-esteem has a positive influence on body weight, and children whose parents received a higher level of education have a decreased risk of being overweight or obese.
Household income, however, was not significant, indicating that is the educational dimension of parents' socioeconomic status that matters most for adolescents' weight status.
Interestingly, the stronger the social bonds are between parent and child, the more likely the child is to be overweight. Crossman speculates this can be attribute to several factors.
"The closer children are to their parents, the more likely they are to internalize the values and norms that their parents promote or model. Nearly two-thirds of adults are overweight and 30 percent are obese," she says. "Other reasons might include over eating due to separation anxiety when the child leaves the home, or parents not wanting to criticize their children's eating habits when they are young."
Contrary to other reports, Crossman found no evidence that children who live in single parent or stepparent households are more likely than those who live with two biological or adoptive parents to be overweight or obese as young adults.
In addition, she found that race and ethnic differences are insignificant.
The prevalence of excessive weight among American adolescents has increased dramatically over the past 25 years. Approximately 15 percent of children age 12 to 19 are currently overweight or obese, a one-third increase since the late 1970s.
Experts report that if this incidence of excessive body weight continues to rise, being overweight or obese will soon surpass cigarette smoking as the number one cause of preventable disease in the United States.
"Our research suggests that prevention must begin at home," Crossman says. "We need a public health campaign that educates all adults and children in the home on the importance of creating a family environment that promotes healthy habits."
Crossman has several suggestions for families. Parents and other caretakers should be urged to exert control over children's diets, including making a healthy breakfast a priority, and to limit the amount of free time that children have to spend on sedentary activities.
Parents and other caretakers also need to be made aware that promoting a positive self-esteem in children is also an important element in preventing them from the long-term health risks of excessive weight.
Finally, parents who are obese need to understand that they are putting their children at high risk for becoming overweight or obese by modeling unhealthy habits.