By Krista Scott-Dixon, PhD

One for the "kids these days" file: Not only do they have funny haircuts, need to pull up their pants, and play that darn music too loud, it seems that they're getting bigger and more out of shape, too. The rate of childhood obesity has grown significantly in recent years and along with it parental and medical concerns over what this means for their health.

Why worry about overweight kids?

But why worry about overweight kids? After all, isn't it just a bit of baby fat? For one thing, excess body fat in both children and adults is often a symptom of under-active and poorly or over-nourished bodies. As children grow and develop through crucial stages, it is critical that they get the best chance for optimum health via regular exercise and good quality food intake. Bodies that are overweight in early stages have a much harder time getting to and staying within a normal or ideal body fat range later.

Dangers of childhood obesity

Many obese children show early stages of health conditions such as type II diabetes (see also Juvenile Diabetes) and cardiovascular disease--conditions that used to be considered health problems of the middle-aged and elderly population. Poor nutrition and lack of activity can also contribute to behavioral and cognitive problems: Kids act up and get cranky, do worse in school, and have more problems learning. Additionally, underlying health problems such as asthma and allergies can be aggravated.

Obesity and Television: A Worldwide Epidemic?

In Canada, kids between age 2 and 11 watch an average of 14.1 hours of TV per week, or about 2 hours per day. That is equivalent to a part-time job! It is not hard to guess that plenty of time spent vegetating on the couch might add up to fatter kids.

For instance, a recent study in the British Medical Journal (Reilly et al. 2005) looked at various factors that might contribute to childhood obesity. Along with parental obesity and short sleep duration, among children older than 3, obesity was strongly associated with over 8 hours of TV watching per week. A study comparing 34 countries confirmed that TV was linked to higher risk of being overweight (Janssen et al. 2005). Big surprise, North Americans and Western Europeans, who are likely to watch more TV, did not fare very well.

Does watching TV cause childhood obesity?

So what's the relationship between TV watching and obesity? It's not always clear. Although TV watching has been strongly correlated with obesity, it doesn't necessarily mean that TV per se causes obesity. Research suggests that TV watching can be a risk factor for childhood obesity, largely because TV can substitute for other activities.

However, another study (Grund et al. 2001) that confirmed the connection between TV and fat suggested that, in fact, reduced activity could not fully explain the higher rates of obesity. Rather, this study linked socioeconomic status to both TV watching and obesity--in other words, both TV watching and obesity may be independent factors that are connected by a third factor such as income, parental education and knowledge of nutrition, availability of parental supervision for activity, etc.

What we do know, though, is that whatever the reason, more TV adds up to poorer health outcomes and higher body fat levels for both kids and adults. So grab the remote, turn off the TV, and get the whole family outside!

For more information on TV watching and childhood obesity see the following article from TheDietChannel: What Causes Childhood Obesity?