TV Watching and Feeling Unsafe at School Up Childhood Obesity

Miriam E Tucker

May 05, 2015

Watching even 1 hour of television a day and feeling unsafe at school both increase the chance a child will be overweight or obese, new research shows.

Findings from the television-watching study — an analysis of a large nationally representative sample of kindergarten and first-grade children — were presented April 26 at the Pediatric Academic Societies 2015 Annual Meeting in San Diego by Mark D DeBoer, MD, associate professor of pediatrics in the division of pediatric endocrinology at the University of Virginia, Charlottesville.

"The main message for clinicians is that it is still important to remember to ask about TV viewing and recommend that parents significantly restrict viewing time. The American Academy of Pediatrics recommends that children over 2 have no more than 2 hours daily of total screen time. Our data suggest that even further restriction may be beneficial for avoiding unhealthy weight gain," Dr DeBoer told Medscape Medical News.

In other research, the experience of poverty and feeling unsafe at school were also identified as risk factors for pediatric obesity by Dr Carolyn Côté-Lussier and colleagues at the University of Montreal and its affiliated Research Centre at CHU Sainte Justine children's hospital, in a new paper published online April 28 in the American Journal of Epidemiology.

Asked to comment on that study, Dr DeBoer said, "There are a variety of reasons why children and adults eat more than a healthy amount of food. Feeling unsafe and other sources of anxiety can lead to eating for comfort."

In addition, "poverty can be associated with a fear of continued food availability — ie, food insecurity — which can cause one to eat more now out of fear that food will be scarce in the house at a later time. Also, many healthy foods are more costly, and many inexpensive foods contain a large amount of fat and processed carbohydrate —both contributing to more weight gain," he observed.

Both papers offer insights for clinicians, he noted. "Other studies have suggested that pediatricians do have some influence over their patients' choices. These articles highlight some areas for pediatricians to emphasize and to [help] identify children on whom to focus particular attention."

TV Viewing Risk

Dr DeBoer and colleagues analyzed data for 14,645 participants in the Early Childhood Longitudinal Survey – Kindergarten, cohort 2011, funded by the US Department of Education. Data on body mass index (BMI) and television viewing were available for both kindergarten and first grade for 7324 of the study population.

Overall for the kindergarteners, parents reported that their children watched an average of 2 hours of TV each weekday and 14.7 hours per week (including weekends). A third of the kindergartners were reported to be watching more than the 2-hour AAP-recommended maximum.

Television viewing time was slightly less among the first-graders, 1.6 hours per weekday, and 16% were watching more than 2 hours per day. However, when video-game use was added in, more than a third of the first-graders (37%) had more than 2 hours of daily screen time.

Even after adjustment for sex, race, and parental income and education, the child's BMI score increased by 0.03 for every 1-hour increase in weekday TV viewing in both kindergarten and first grade.

Compared with children who watched less than 1 hour of TV a day, the odds ratios for being overweight or obese for those who watched 1 to 2 hours and 2 or more hours were 1.48 and 1.50, respectively, in kindergarten and 1.64 and 1.80 for first grade. There was no relationship between computer or video-game use on BMI-z-scores at either time point.

At both time points, the difference between children watching less than 1 hour of TV a day vs 1 to 2 or more than 2 hours translates to weight differences of about 0.28 and 0.35 kg, Dr DeBoer and colleagues estimate.

Children who were not overweight or obese in kindergarten and watched 1 to 2 hours of TV per day or more than 2 hours per day were at greater risk for becoming overweight by first grade compared with those watching less, with odds ratios of 1.65 and 1.93, respectively.

Dr DeBoer told Medscape Medical News, "Lifestyle practices are difficult to change, and the more that we inform parents about the health-related dangers of TV viewing and other habits, the better chance we have of influencing these behaviors."

Asked how pediatricians might advise parents to cut their children's TV time without a battle, he said, "Restricting time will take trying to fill that time. Additional time to play outdoors, read books, have books read to them, and other activities will be helpful. There may be tantrums at first, but being firm and doing activities with the children will help to avoid tantrums."

Fear and Obesity: Boys Most Affected

Meanwhile, Dr Côté-Lussier and colleagues examined data from the Québec Longitudinal Study of Child Development (QLSCD), a prospective trial designed to improve knowledge about the psychosocial development of children. It began in 1998 with a representative population-based birth cohort of 2120 infants 5 months of age and their parent or primary caregiver. This study focused on a total 1234 who were 13 years of age to 2011.

Approximately a third experienced poverty at some point, and about a fifth reported not feeling completely safe at school. Nearly a third (31%) were either overweight or obese.

After adjustment for weight-related factors, those who experienced chronic poverty were more likely to be overweight or obese than those who did not. The youths who experienced chronic poverty were less likely to report feeling safe at school and, in turn, were more likely to be overweight or obese, the authors report.

Victimization contributed to the relationship between poverty and weight, although it didn't entirely explain it. That is, the youths who experienced chronic poverty also reported higher levels of victimization and feeling unsafe at school, which was in turn associated with greater likelihood of being overweight or obese.

Boys were more likely than girls to report being victimized at school, and this was also associated with an increased likelihood of being overweight or obese, Dr Côté-Lussier and colleagues report.

"Improving youths' weight-related behaviors and reducing obesity rates require that we address the obesogenicity — or obesity-promoting features — of youths' environments," they write.

"Increasing youths' feelings of safety at school is therefore a potential intervention that could buffer the association between poverty and overweight. Such interventions may be particularly important for youths who experience early childhood and chronic poverty, as their weight status is most strongly associated with feelings of safety at school," they note.

"These interventions would be especially beneficial for boys, who report more victimization at school and may therefore be particularly likely to experience rejection or neglect by peers, engage in poorer health habits, and in turn experience more behavioral, emotional, and health problems," they add.

Are There Two Types of Childhood Obesity?

Separately, another study of 307 UK children — published online April 27 in the International Journal of Obesity by Mohammod Mostazir, from the Plymouth University Peninsula Schools of Medicine and Dentistry, United Kingdom, and colleagues — suggests that childhood obesity might follow two distinct trajectories, with different causes.

By comparing this contemporary cohort of children with those who grew up a generation earlier (in the 1980s), they found that the rise in obesity in children less than 5 years of age has been largely restricted to the minority with obese parents. Outside the toddlers of obese parents, there was little change in BMI over a generation.

But obesity that developed among adolescents did so regardless of parental weight. The data suggest that parenting is the fundamental influence on weight gain in the early years, whereas more general (peer-group) influences take over later on, say the researchers.

In a statement, senior author Prof Terence Wilkin, from the University of Exeter Medical School, United Kingdom, commented, "This study indicates for the first time that childhood obesity has different causes, depending on the age of the child. Childhood obesity is one of the greatest health issues of our time. If we are to develop strategies to intervene effectively, we must first understand the cause."

None of the authors have reported relevant financial relationships.

Pediatric Academic Societies 2015 Annual Meeting. April 26, 2015; San Diego, CA. Abstract

Am J Epidemiol . Published online April 28, 2015. Abstract

International Journal of Obesity. Published online April 27, 2015. Available at


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