Wednesday, November 11, 2009

Shocking new study on how TV causes pediatric obesity.

Ok, maybe not so shocking.

In my talks on childhood obesity I'll always point out that the simple act of sitting on a sofa doesn't in and of itself cause weight gain and on my blog I'll also regularly point out that the rise in childhood obesity isn't a consequence of a lack of physical activity, but rather an increase in food. Putting those two together I've always presumed that TV watching was symptomatic of a less healthy lifestyle that included more calories than the lifestyles of kids who didn't watch much TV.

Well guess what? Maybe I was right. A fascinating study was recently published in the journal Obesity that specifically sought to answer what it is about watching TV that leads kids to gain weight. The study looked at the TV viewing habits, lifestyles and weights of 2,374 Greek children between the ages of 1 and 5.

The findings?

Those kids watching the most TV were indeed the heaviest and this relationship persisted even after controlling for potential confounders like physical activity. What this means is that kids who exercised and watched lots of TV still had the same rates of obesity as the kids who didn't exercise and watched lots of TV.

So what was the cause? The researchers studied many different variables but at the end it came down to the simple fact that the kids who watched the most TV consumed the most calories.

Now exactly what, when and why they're eating more isn't yet clear. Are they eating more junk because they see more commercials for junk? Do they sit there with a bag of chips in their laps (the researchers think indeed, it's food consuming while watching TV that makes the difference), or are they eating more in the hours they're not watching TV? The stuff for future research.

Bottom line? Once again it seems it's about intake and not output.

Manios, Y., Kourlaba, G., Kondaki, K., Grammatikaki, E., Anastasiadou, A., & Roma-Giannikou, E. (2009). Obesity and Television Watching in Preschoolers in Greece: The GENESIS Study Obesity, 17 (11), 2047-2053 DOI: 10.1038/oby.2009.50

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  1. I noticed this summer that my 11yo son was getting a bit chubby, but once school started and I was making his breakfast and sending his (mostly healthy) lunch and he didn't get home until after 4pm, with a single snack before a healthy dinner, he's slimmed right down again!

    I think being at home with readily-available treats is the real culprit--and explains a lot about the overweight of stay-at-home and work-at-home moms, too.

    I still like home, but it needs careful attention!!!

  2. Anonymous9:53 am

    Re Cindy's comment about home having more treats:

    Isn't it interesting that the rise in obesity has been over the same time that the kitchen has become incorporated into the family room or great room in American house design.

    On the one hand it's good that mom, the cook, isn't slaving alone in the kitchen. Now the family is supposed to cook together, or at least be able to talk to the cook.

    But now, in one big room, you're ALWAYS in the kitchen. The TV is near the kitchen, with hungry-making food ads as cues to go eat. If you're reading or playing games or whatever, you're practically in the kitchen. Some designers are even proud of putting in "snack stations" so kids have a dedicated mini-fridge and cupboard for their yummy snacks.

    If you wanted to design a house to increase food consumption, and specifically to increase junk food consumption, you couldn't do better than to essentially put the fridge, stove and food storage in the middle of the living room, and then add a TV with fast food ads.

  3. Great comments.

    I wonder if there have been any studies done on home design and obesity rates.

    Would the open-concept homes put families at greater risk?

  4. I have four kids and have homeschooled for 13 years. Obviously then we all are mostly at home, much of the time. Some days I'll admit to feeling like I never get out of the kitchen. However I have to say that we all are slender. Two of my sons are grown (and gone!) What I think might actually be advantageous about dwelling at home, is that we are able to graze on a variety of readily available snacks and mini-meals. I eat often throughout the day, but have maintained a very healthy weight. It seems to me it's a pretty complex thing, this lifestyle / weight correlation.

  5. This is quite interesting because most studies show a direct relationship between sedentary lifestyle and weight gain i.e. that children who don't exercise will be heavier and less healthy than children who do exercise. But this study suggests that even ACTIVE children maybe more prone to obesity if they watch too much TV.

    Several studies have shown a connection between obesity, exercise and self-esteem in children. Children who had lower self esteem tended to be heavier than children who had a healthy view of themselves; another study found that depressed children tended to be lonely and lacked motivation to exercise. You can read about it in this article:

    It would be interesting to know whether the children who watch a lot of TV are also lonely, spending more time at home because they have few children with whom they can play.

    Published daily, "Living Fit, Healthy and Happy" is a family-friendly physical fitness resource website with articles on fitness, anti-aging, obesity, diabetes, eating disorders, cardiovascular health and many other health related issues. There's always something for you at "Living Fit, Healthy and Happy".

  6. Could it possibly be that children who watch more tv are more obese because they are eating "food" instead of food?

    Food is an edible found in its own packaging: all fruit & veggies, recognizable meat (chicken, hamburger, pork chops), and some dairy like yogurt and milk. These items are nutrient rich and have fewer calories overall. Your body takes longer to digest them and use this food.

    "Food" is an edible that has been processed but may not contain anything that was once alive. Things like: Go Gurt, Froot Loops, Doritos, and Pogos. These items are calorie rich and nutrient deficient. Your body easily processes this "food" and leaves you hungry sooner.

    (An example of the above: one banana contains the same calories as two Oreo cookies. I can eat a whole bag of Oreos in one sitting, but there is no way I could eat 15-20 bananas in one sitting.)

    Couple that with the fact that tv disengages your brain from your body. As long as your brain is distracted it cannot properly prioritize the messages of "I'm full" or "I need more folic acid, please". So if feelings of fullness are ignored, more stuff can be sent down. If messages indicating which nutrients are needed are ignored, the body can continue packing itself full of garbage in hopes of getting the right stuff.

    So, here you have a child parked in front of a tv with a large bag of chips and some soda. The "food" has lots of calories but almost no nutrients. Your body needs the nutrients and will keep sending messages to the brain to send some down. The brain is busy receiving the stimulus of the tv and is having difficulty in prioritizing the messages. The body then will continue eating as long as the body's owner has something at hand to eat.

    Triple that with the "food" industry's creation of the Bliss Point: sugar, fat, and salt combination. This deadly combination hits the reward center of your brain first, causing the person to crave and seek out this stuff. To make matters worse, the media constantly bombards people with images and good feelings about this stuff, causing the reward center in your brain to awaken and begin craving.

    So you sitting in front of the tv, eating "food" and watching images that reinforce the craving for this "food". Your body digests this "food" very quickly to make room for more. You see more on tv, you eat more.

    We created this. Can we stop this?