Children who consistently spend more than 4 hours per day watching television are more likely to be overweight. Health experts have long linked excessive TV watching to weight gain. While watching TV, kids are inactive and tend to snack. They're also bombarded with ads that encourage them to eat unhealthy foods. The problem isn't just how long children are watching TV but, what they are watching. According to William H. Deitz, pediatrician and prominent obesity expert at Tufts University School of Medicine, "The easiest way to reduce inactivity is to turn off the TV set. Almost anything else uses more energy than watching TV."

Television affects the health of both children and adults. First and foremost, television ads are constantly bombarding us with information about health and nutrition, and unfortunately, most of it’s skewed. Our children are most susceptible to these leading advertisements. For instance, children may have a hard time recognizing fact from fiction when they see an ad that shows thin beautiful people enjoying high calorie, high fat foods and drinks. Roughly two-thirds of the 20,000 TV ads an average child sees each year are for food and most are for unhealthy foods. The majority of children who watch health related commercials believe what the ads say, even if the ads do not give accurate or balanced information.

Watching television also affects one’s health by replacing other activities and by slowing the metabolic rate. Television viewing leads to obesity in children and adults when it replaces other, more active pursuits, such as walking, biking, or simply playing outdoors. All television shows, even educational non-commercial shows, replace physical activity. And watching TV is a sedentary activity that causes the metabolic rate to go even lower than when one is at rest. This means that you can burn more calories by just sitting quietly and doing nothing than you can when you sit and watch TV.

Finally, TV leads to obesity in children and adults because of the foods that are typically consumed when one is watching TV. Most people tend to snack while watching TV, choosing junk foods that are convenient to eat in front of the television.

Kids who watch too much TV are usually overweight, according to the American Medical Association. Kids often snack on junk food while watching TV. They are also influenced by commercials to consume unhealthy food. Also, they are not running, jumping, or doing activities that burn calories and increase metabolism. Obese kids, unless they change their habits, tend to be obese when they become adults. The more television a child watches, even in the first years of life, the more likely he is to be obese and less muscularly fit, according to a study by the University of Montreal. Even though your kid does not aspire to be a football star, his athletic abilities are important not only for physical health, but predicting how physically active he will be as an adult

Risky Behavior

TV shows also promote risky behavior in teens. KidsHealth explains that on TV shows, teens and adults are often portrayed doing drugs, smoking, drinking and having premarital sex. This encourages teens who watch to participate in the same types of risky behavior. KidsHealth says teens who watch TV shows that portray a lot of sex are more likely to have premarital sex than those who don't watch those types of shows. Teens who watch five or more hours of TV a day are also more likely to smoke than those with limited TV time, says KidsHealth.

Read more: http://www.livestrong.com/article/156911-effect-of-tv-shows-on-teen-behavior/#ixzz29glmSrNf

As many studies have proven, viewing television violence can and does lead to aggression in children. Why does this correlation exist and what causes a child to become aggressive? There are a number of theories in regard to this. One theory is the more violence a child views the more of their natural sensitivity toward violence is lost.
Children learn and imitate that which they see. "Building on the accumulating evidence that human and primate young have an innate tendency to imitate whomever they observe, these theories propose that very young children imitate almost all specific behaviors they see. Observation of specific aggressive behaviors around them increases children's likelihood of behaving exactly that way" (Eron 201). If a child sees their television heroes acting violently they are going to be instinctually prone to act the same way.

TV exposes your kid to negative influences, and promotes negative behavior. TV shows and commercials usually show violence, alcohol, drug use and sex in a positive light. The mind of your kid is like clay. It forms early impressions on what it sees, and these early impressions determine how he sees the world and affect his grown-up behavior. For instance, twenty years of research has shown that children who are more exposed to media violence behave more aggressively as kids and when they are older. They are taught by TV that violence is the way to resolve conflict – as when a TV hero beats up a bad guy to subdue him.

Kids who watch a lot of TV have trouble paying attention to teachers because they are accustomed to the fast-paced visual stimulation on TV. Kids who watch TV more than they talk to their family have a difficult time adjusting from being visual learners to aural learners (learning by listening). They also have shorter attention spans.
School kids who watch too much TV also tend to work less on their homework. When doing homework with TV on the background, kids tend to retain less skill and information. When they lose sleep because of TV, they become less alert during the day, and this results in poor school performance.

Dr Sigman - who is also a child health expert - has made a raft of suggestions for children's screen consumption including delaying the age children start using screens to at least three.

Children aged between three and seven should be limited to half-an-hour to an hour of screen time each day, he said.

Those aged seven to 12 should spend just one hour in front of screens.

Children aged 12 to 15 should have a maximum of 1.5 hours in front of screens and those age
Behavioral problems. Elementary students who spend more than two hours a day watching TV or using a computer are more likely to have emotional, social and attention problems. Exposure to video games also increases the risk of attention problems in children. Children who watch excessive amounts of TV are more likely to bully than children who don't.d 16 and over should spend just two hours, he recommends.

First is imitation; children who watch violence in the media can internalize the message that the world is a hostile place, he explains, and that acting aggressively is an OK way to deal with it.

Also, he says, kids can become desensitized to violence. "When you're exposed to violence day in and day out, it loses its emotional impact on you," Huesmann said. "Once you're emotionally numb to violence, it's much easier to engage in violence."