What’s New in Psychology?

Childhood TV Viewing May Lead to Adult Metabolic Syndrome        

Jim Windell

            Many parents these days view television as an inexpensive form of babysitter. Most TV programing is colorful, fast-paced and entertaining – perfect for keeping kids engaged while mom and dad do household chores or conduct business on their laptop.

          Not that most parents don’t know this is not a good idea. After all, the American Academy of Pediatrics advised parents to limit screen time for kids as long ago as 1999. Confront any parent about the number of Disney DVDs their kids watch and watch many times over and the reaction is likely to be something like: “I know they shouldn’t watch so many videos on TV, but honestly they love them.”  And then they may add, “And it helps me to get things done.”

          I’m certain that most parents rationalize the amount of time spent in front of TV or computer screens and argue to themselves that screen time might not be good for kids but they don’t really watch TV programs, play games or view videos “that much.”

          However, a new warning has just come along that contends that while moms and dads might not see the long-term consequences of a lot of screen time, nonetheless their children will pay the consequences at some time in their lives.

            Published recently in the journal Pediatrics, a new article reports on a study that links excessive television viewing during childhood to adverse health outcomes in adulthood.  The study, led by Professor Bob Hancox from the Department of Preventive and Social Medicine at the University of Otago in Dunedin, Otago, New Zealand, reveals that children who spent more time watching television were at a higher risk of developing metabolic syndrome later in life.

           For the study, metabolic syndrome was said to encompass a collection of health conditions such as high blood pressure, elevated blood sugar levels, excess body fat, and abnormal cholesterol levels – all of which contribute to an increased susceptibility to heart disease, diabetes and stroke.

           To study the effects of television viewing, data from 879 participants who were part of the Dunedin study was analyzed. The data studied was the participant’s TV viewing habits from ages 5 to 15. During the study, participants were asked about their television viewing habits at ages 5, 7, 9, 11, 13, and 15. It was found that, on average, they spent just over two hours watching TV on weekdays.

           Additionally, once the cohort members turned 45 years old, the researchers measured their blood pressure, blood sugar levels, body weight, waist circumference, blood cholesterol and triglycerides to put together their metabolic syndrome. The researchers found that mean TV viewing time between ages 5 and 15 years was associated with metabolic syndrome at 45 years of age – even after adjusting for factors like sex, socioeconomic status and body mass index at age 5 years. It also persisted after adjusting for adult TV viewing.

           According to Bob Hancox, “It is actually the amount of time you spend watching TV or using a screen as a child that predicts long-term adult health.” Furthermore, he points out that increased childhood television viewing was linked to a higher probability of being overweight or obese and having lower physical fitness.

           Hancox also commented that “Age 45 is still a bit young to actually develop diagnosable heart disease and diabetes and other things that tend to happen a decade later in life, but there's this collection of risk factors which tend to go together called metabolic syndrome, which actually has become quite common in midlife adults. We wondered how much sedentary behavior predicted the long-term risk of metabolic syndrome.”

           Interestingly, the research provided little evidence to suggest that reducing television watching in adulthood could mitigate the association between childhood television viewing and adult health outcomes.

           Although Hancox and his associates acknowledge that like any observational study they cannot definitively prove that television viewing during childhood directly causes adult metabolic syndrome, there are several plausible mechanisms that could explain the link between longer television viewing times and poorer long-term health. Hancox explains that television viewing typically involves low energy expenditure, potentially displacing physical activity and leading to reduced sleep quality. Additionally, excessive screentime might encourage higher energy intake, with children consuming more sugar-sweetened beverages and high-fat foods while consuming fewer fruits and vegetables. Such habits formed in childhood may persist into adulthood, contributing to adverse health outcomes.

           The significance of these findings is heightened by the fact that screen times have increased significantly in recent years due to the proliferation of new technologies. Children today have far more access to screen-based entertainment, which includes smartphones and tablets, and spend a substantial amount of time in sedentary activities. Consequently, it is highly probable that this trend will have even more detrimental effects on adult health in the future.

          The study was accompanied by an editorial authored by Pooja S. Tandon, MD, MPH, a pediatrician and researcher at the Center for Child Health, Behavior and Development at Seattle Children’s Research Institute. “A significant body of literature reveals the known child health risks of excessive and/or inappropriate screen time, including unhealthy diet, sleep problems, excessive adiposity, poor cardiometabolic health, and increased mental health concerns,” Tandon wrote. “What is less well characterized are the long-term consequences of media use in childhood.”

           Tandon continued by writing that, disappointingly, the authors found that the relationship between childhood TV viewing and metabolic syndrome at age 45 years persisted after they adjusted for TV viewing at age 32 years.

           “Although the benefits of decreasing sedentary behaviors and media use certainly exist in adulthood, as well, these findings underscore the critical and potentially disproportionately larger influence of the childhood years on cardiometabolic health risks,” Tandon wrote. “If early media use is, in fact, causally related to adult metabolic syndrome, the mechanism, however elusive, has important public health consequences. Some emerging evidence reveals that the ‘exposure’ early in childhood creates epigenetic changes that predispose to obesity. Seen in this light, limiting screen time in young children takes on even greater urgency.”

           To read the original article, find it with this reference:

MacDonell, N., & Hancox, R. J. (2023). Childhood and adolescent television viewing and metabolic syndrome in mid-adulthood. Pediatrics, 152(2), e2022060768.