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K E Y P O I N T S

According to the Royal College of Physicians, obesity has soared in adults, from 6 per cent of women and 8 per cent of men in 1980, to 21.4 per cent of women and 21 per cent of men now.

Obesity is a risk factor for the development of type 2 diabetes.

BMI stands for body mass index. A person with a BMI of between 25 and 30 is regarded as being overweight, and if it's 30 or more, obese.

A study of more than 68,000 American women found the length of time spent watching TV correlates with the likelihood of obesity and type 2 diabetes.

Experts state that frequently watching television for lengthy periods, and having a sedentary lifestyle, can contribute to obesity and diabetes.

Being more active each day and eating healthily can reduce the risks.

Does TV watching harm health?

Bupa investigative news - 29 April 2003
written by Rachel Newcombe, reporter for Bupa's Health Information Team

The incidence of obesity is rising in the UK, causing concern among experts and increasing the risk of serious disease for individuals. Relaxing in front of the television is a favourite pastime for many but, according to researchers it is not helpful to health. A study showed that regularly watching two hours of TV a day increased the risk of becoming obese by 23 per cent and the risk of developing diabetes by 14 per cent. So, should we switch off the TV completely or are there other ways of reducing the risks?

What were the headlines?

The finding that television could be bad for your health was picked up by a number of publications in the UK and worldwide.

Examples of headlines include, "TV watching 'makes you obese'", "Long TV sitting raises obesity risk", "Female couch potatoes beware", and "Prolonged TV watching increases obesity and diabetes risk".

What is the bigger picture?

Researchers from the Harvard School of Public Health used data from the Nurses' Health Study to look at the links between sedentary behaviour and health. Their findings appeared in the Journal of the American Medical Association.

More than 68,000 women were assessed for six years. All participants started with a body mass index (BMI) of 30 or less (a BMI of between 25 and 30 is considered overweight, and more than 30 is regarded as obese) and were free from diabetes, heart disease and cancer. The women completed a questionnaire about their lifestyle and behaviour at the start, and follow-ups were completed every two years.

During the six-year period, more than 3700 women became obese and more than 1500 new cases of type 2 diabetes were diagnosed.

Regularly watching two hours of TV a day increased the risk of becoming obese by 23 per cent and the risk of developing diabetes by 14 per cent. Other sedentary behaviours, such as spending a lot of time sitting at home or work, were also detrimental to health - not to the same extent.

In contrast, active lifestyles were found to reduce health risks. Standing or walking for two hours per day was associated with a 9 per cent reduction in risk of obesity and 12 per cent for diabetes. Each hour per day of brisk walking was associated with a 24 per cent reduction in risk of obesity and 34 per cent reduction in risk for diabetes.

Frank Hu, lead researcher and associate professor of nutrition and epidemiology at the Harvard School of Public Health said, "The message is simple - when you cut back on sedentary behaviour, you cut back on the risk of developing type 2 diabetes and obesity which lead to serious health risks."

He added that, "Excessive time in front of the TV has been shown to contribute towards bad eating habits, such as eating foods high in saturated fats and increased calorific consumption. Incorporating more physical activity shows the greatest protection against obesity and diabetes; brisk walking, even doing chores around the yard and house can help."

“If parents frequently sit and relax in front of the television for hours, children could learn bad habits. Sometimes, particularly with younger children, parents will lead them towards watching television because it keeps them occupied and leaves them time to get on with jobs. There's a real health danger for older children, particularly those who like television and computer games, as many don't have enough physical activity, other than what schools offer. As well as encouraging regular activity, a balanced nutritious diet is important for a healthy lifestyle.”

Jeanne Barczewska,
childcare consultant, Bupa Teddies Nurseries

What does this mean?

Professor Anthony Barnett, a diabetes specialist from the University of Birmingham and Birmingham Heartlands Hospital, is not at all surprised by the findings. "The numbers of hours watching TV is just a surrogate marker for inactivity," he explained. "In other words, those people who watch the TV for many hours a week are clearly not exercising, not moving around, and are therefore much more likely to develop obesity. And obesity is, of course, a major cause of type 2 diabetes - so it all fits."

"There's no question that the most important reason for the explosion in obesity rates in the last 20 or 30 years is sedentary lifestyles. The amount of activity people take has dramatically reduced and that has coincided with a trebling in the obesity rates," he added.

Dr. Ian W. Campbell, chair of the National Obesity Forum, agrees. "Without a doubt watching television has had a role to play, simply because we watch such a lot of it."

Debbie Hammond, a care advisor from Diabetes UK, said, "Obesity is a very significant factor in the development of type 2 diabetes and we're growing increasingly concerned about the large number of people developing it. Part of the obesity problem stems from a change in lifestyle - a reduction in physical activity levels and changes in eating habits."

James Rogers, executive director of the Diabetes Research and Wellness Foundation (DRWF) said, "It is absolutely essential that we address prevention if we are to avoid a diabetes epidemic in this country. The risk of developing diabetes grows as body fat increases, so we must encourage people to take action and take the necessary steps to stay at a healthy level."

A C T I O N P O I N T S

Work out ways of increasing your daily activity.

Television watching in moderation is fine, but try and be active too.

Encourage your children to be active and eat healthily.

Make modest changes to your diet and cut down on fatty, sugary and salty foods.

What does this mean to me?

"Watching television can be a major contributory factor," said Debbie Hammond, but it doesn't mean you have to give it up completely.

"A brisk walk, for a minimum of half an hour every day, will do no end of good," suggests Professor Barnet. "So, even if you're going to watch television for several hours, a brisk walk will actually counteract a lot of those problems."

Diabetes UK also recommends a minimum of 30 minutes of exercise a day, but stress that it doesn't have to be vigorous. "So often people see physical activity as going to a gym, but it doesn't need to be that," said Debbie Hammond. "It can be just simple things, like walking to work, walking to the train, getting off the bus two stops early. Just small amounts on a regular daily basis all add up and make a difference."

Changing eating habits is important too but, again, doesn't have to be drastic. "The majority of people gain weight very slowly, one or two pounds a year, because they've been consuming, perhaps, 100 calories too many each day or been less active over several years. I'd encourage people to start making modest changes, such as cutting down on sugar in tea, choosing low fat and low sugar foods and not eating when they're not hungry," said Dr. Campbell.

With obesity increasing in children and adolescents, it's vital to teach them about healthy eating and activity before it's too late. "We're already seeing what we assumed to be diseases of middle and old age people in children and adolescents," said Dr. Campbell. "They have impaired glucose tolerance, high blood pressure, high cholesterol levels. What we're seeing with the growth in childhood obesity is the disease of tomorrow developing. Therefore it's crucial we do something about it now and not tomorrow."

Summary

Although television is enjoyable, long hours without activity can contribute to obesity and diseases such as diabetes, and is a risk for both adults and children. Experts advise being more active every day and eating healthily.