Does electronic media make kids fat?

Why are today’s kids so much heavier than kids of previous generations?

The classic answer is that kids today are taking in more calories and spending less energy: They spend less time playing outdoors and have stopped working on the farm and doing chores – but hey, haven’t they stopped doing that a long time ago?

The energy expenditure side of the equation is the pet project of fast-food and junk-food makers.  Oh, if we could only give kids another hour of gym! If only kids could balance their ravenous appetite for snacks with a little more outdoor play we wouldn’t have to voice the unthinkable “eat less” advice.

But the numbers just don’t add up.  In order to eat like the TV ads suggest kids would have to increase physical activity to what amounts to no time left for homework or sleep.

I’d like to take an honest look at how sedentary activities really affect kids’ waistlines. 

An article in Obesity Reviews looked at the current trends of childhood pastimes, and how those affect not only energy expenditure, but also energy consumption.  Let’s take a look:

TV viewing

Kids watch many hours of TV and high rates of TV viewing are correlated with obesity.  While sitting on a comfy couch is super sedentary, watching TV has many other effects on energy balance. 

20-25 percent of daily calories are consumed in front of the TV.  This distracted eating increases intake of calorie-dense food (i.e. highly processed foods with lots of calories).

A study showed that 36 percent more pizza and 71 percent more mac&cheese were consumed when eaten in front of the TV, compared to meals eaten without the TV on.

For many people TV watching is associated with snacking.  They’ll munch while watching whether hungry or not, and if they ever forget to bring the munchies, an ad – so many of the TV ads are for junk-food -- will no doubt remind them that something is amiss.

Video games

Video and computer games fill many hours in the average kid’s day.   Video games are relatively new, and their effect on obesity has been studied less extensively than that of TV's, but observational studies show a connection, and a recent study showed obesity and overweight doubling for every extra hour spent playing electronic games.

Again we can argue that (non-active) video games are pretty sedentary, but the studies show that playing video games makes kids eat more.  Just like TV, video gaming leads to eating, the reflexive non-hunger kind of eating.

And don’t forget advertisers target video gamers on these platforms, too.

A single session of video game play in healthy male adolescents is associated with an increased food intake, regardless of appetite sensations.

Sleep

Who wants to sleep when there’s so much to do?  The presence of electronic devices such as a computer, TV or smart phone in the bedroom has been shown to delay sleep.

It seems counterintuitive, but shorter sleep duration is associated with increased risk of obesity.  It might be that being awake at night gives opportunity for late-night snacking; it might be that fatigue leads to inactivity the next day; and maybe lack of sleep messes up our hunger and appetite regulation.

We’re sleeping less – studies show that sleep has gone down by more than an hour over the past decades – and since sleep isn’t a waste of time, the barriers to sleep (many of them electronic) are hurting our health.

Media consumption begets food consumption

A recent Kaiser Family Foundation study showed that 8-18 year-olds devote an average of 7½ hours (!) to using entertainment media in a typical day.  Much of that time is spent media multitasking -- using more than one medium at a time. From what we learn from other studies we know that much of our kids’ multitasked media time also involves another added and almost automatic activity: snacking. 

Much more significant than the low energy expenditure toll of media consumption is its pairing with distracted eating.

Victorian ladies weren’t known for their workouts.  But they didn’t snack while embroidering.  Eating used to be prompted by hunger and traditional mealtimes.  Now, it’s prompted by an ad and constant availability of highly processed high-calorie food.

Uncoupling the TV, computer and video from it’s by now natural companion – sugary drinks, snacks and ready to eat meals – is a tall task.

Any ideas on where to start?

Dr. Ayala