Tag Archives: Physical Activity

Screen use at seven: overweight at 11. Why it’s time to say no to a TV in the bedroom for children

Since the launch of the Childhood Obesity Strategy in 2016, there has been much attention focused on the so-called ‘Sugar Tax’. The March 2017 Budget saw confirmation that sugary soft drinks would be taxed in an attempt to combat rising levels of obesity. This is an important move that has been met with widespread approval from public health professionals. Still, obesity is hugely complex and there are many other things at play in addition to the sugary drinks and snacks that children may consume. Researchers at UCL have been looking in detail at different factors associated with obesity and, in a recent paper, find that children who have a television in their bedroom have higher BMI and more body fat than those who do not. Lead researcher, Anja Heilmann, explains the research and why saying no to a TV in the bedroom could be another important strategy in combatting childhood obesity.

As our TV screens have got flatter, our children have got fatter. There is no getting away from it! Screen-based activities play a central role in our children’s lives. At a very young age, they have unparalleled access to television screens, computers, game consoles and a host of mobile devices. Among 5 to 11 year-olds, TV is still the most consumed medium, with gaming coming second.

At the same time, childhood obesity is not just a national, but a global health worry. In 2014/15 a third of 11 year-old children in England were overweight and a fifth were obese.

Research has repeatedly reported a link between TV viewing and obesity, but although some has hinted at the idea that a television in a child’s bedroom might exacerbate the problem, the evidence here has been rather contradictory. Other plausible pathways could include eating unhealthy snacks whilst watching TV, exposure to food advertising and insufficient and poor quality sleep.

Using information from the Millennium Cohort Study (MCS), which has followed the lives of more than 18,000 children born around the turn of the century, we had the opportunity to see whether having a TV in their bedroom when they were age 7 was, in any way, linked with a child being overweight when they were 11 years old. In other words, we wanted to get to grips with whether there were implications over a child’s lifetime of their screen use and if so, what those implications were.

Useful information

Using trained interviewers, the MCS collects a wide range of useful information including the independently measured height, weight and body fat of a child. These provided us with a set of obesity-related measurements: weight, Body Mass Index (BMI) and Fat Mass Index (FMI), a powerful set of measures for overweight and obesity.

When the children were age seven, parents were asked if their son or daughter had a TV in their bedroom, how many hours they spent watching TV or DVDs and how much time they spent playing on a computer.

 At age 7, more than half of the 12,556 boys and girls we looked at in our research had a TV in their room and it was these children who were more likely to be overweight when they turned 11 when we compared them with those without a TV. They were also more likely to have higher BMI and FMI. In total, a quarter of the boys and nearly a third of the girls were overweight at age 11 and the links between having a TV in the bedroom and overweight were stronger for the girls.

Another strength of the research is that we controlled for the child’s BMI at age 3 and maternal BMI, that way adjusting for genetic factors, as well as food environment in the family. We also adjusted for family income and mother’s education – both of which are important as overweight/obesity is socially patterned, as is TV use.

Interestingly, there was no link between overweight and the time a child, whether they were a boy or a girl, spent playing on a computer.

Clear link

So, given the size of our sample and the robustness of the methods employed here, we can say with considerable confidence that there is a clear link between having a TV in the bedroom as a young child and being overweight a few years down the line. For girls, this represents a 30 per cent increase in the risk of being overweight at 11 compared with their peers who do not have one. For boys the risk increases by around 20 per cent.

Another interesting point to note is that the size of this risk or effect is about the same as that of other things shown to be linked with obesity, such as not being breastfed and being physically inactive.

Nevertheless, policy makers looking to create and implement strategies to reduce obesity should certainly consider building access to television screens in children’s bedrooms into their thinking. Specific initiatives focused on young girls could also be important.

Meanwhile, for parents who may consider it a good idea for a young child to have their own TV in their bedroom or feel under pressure to provide one, the message is quite clear: resist the idea and you may be doing even more to set your child on a healthier path into their teenage years and beyond.

Longitudinal associations between television in the bedroom and body fatness in a UK cohort study is research by Anja Heilmann, Patrick Rouxel, Emla Fitzsimons, Yvonne Kelly, and Richard Watt and is published in the International Journal of Obesity.

Be prepared: the mental health benefits of scouting and guiding

Being a scout or a guide when we are young might be a good experience for us in all sorts of ways, but can those positive effects be long lasting though our lives and if so, how? Research using the 1958 Birth Cohort shows a strong link between being a scout or a guide when young and better mental health later in life. Professor Richard Mitchell from the University of Glasgow talks to the Child of our Time Podcast about the research, what he and colleagues from Edinburgh found and what he thinks it tells us.

Photo credit: One-and-Other Girl Guides UK

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Putting a SPRING in the step of mums-to-be

Making sure that mums-to-be are in the best possible health is key to ensuring their baby gets the best possible start in life. But what sorts of things can help them achieve that? In this episode of the Child of our Time Podcast, Professor Hazel Inskip from the MRC Lifecourse Epidemiology Unit at the University of Southampton, talks about an ongoing trial making use of healthy conversations and Vitamin D supplements to try to improve the diet of just pregnant women.

Photo credit: Pregnant, Frank de Kleine

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Sugar-coating the childhood obesity problem

Child obesity figures appear to be on the rise again, causing much concern after earlier signs they had levelled off.  The proportion of  10- and 11-year-olds who were obese in 2015-16 was 19.8 percent, up 0.7 percent on the year before. There was a rise of 0.2 percent among four- and five-year-olds. The announcement comes as researchers at the ESRC International Centre for Lifecourse Studies at UCL have been looking in detail at how and when children become overweight. The team has also been asking whether children who are overweight are more likely to go on to smoke and drink alcohol and if their mental health suffers as they become adolescents. Yvonne Kelly explains the research findings, and considers their implications for the Government’s recent strategy for tackling the childhood obesity epidemic.

The Government’s much-awaited and much-debated childhood obesity strategy was published in August. In the end, it was less comprehensive than had been anticipated, less draconian too. It focuses on two things – reducing sugar consumption and increasing physical activity. But will it be effective in reversing this worrying obesity trend among our children?

It’s fair to say we don’t fully understand what things influence whether, when and why a child might become overweight. Research to date has shown three distinct weight pathways for children: a healthy BMI throughout childhood; becoming overweight during childhood and being overweight/obese throughout childhood.

Previous research has also shown that the child’s mother’s weight, smoking in pregnancy, mental health and other social and economic factors have some link to childhood obesity. But the evidence is far from complete and, where a child’s own mental health is concerned, it’s not at all clear which way the association works.

To try to get a clearer picture of all these things, our research looked at the BMI paths of the participants in the Millennium Cohort Study, which has tracked the lives of nearly 20,000 children born between 2000-2002. We used data collected at birth, 9 months, age 3, 5, 7 and 11.

Once we had established who was on which BMI path, we were able to look at what factors were at play in their lives and to see whether a tendency to overweight and obesity was an indication that a child would go on to face mental health difficulties in early adolescence or start smoking and drinking.

Four pathways to obesity

The BMI data for the 17,000 children we were able to look at for our study showed four distinct groups of children. More than 80 per cent of them stayed on an average non-overweight path throughout their childhood – we call it the ‘stable’ path. There was a small group (0.6 percent) of children who were obese at age 3 but were then in the stable group by age 7. We call them the the ‘decreasing’ group. There was a ‘moderate increasing group’ (13.1 percent) where children were not overweight at age 3 but whose BMIs increased throughout childhood into the overweight (but not obese) range. Finally we had a ‘high increasing’ group of children (2.5 percent) who were obese at age 3 and whose BMIs continued to increase.

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Girls were 30 percent more likely to be in the ‘moderate increasing’ group than boys and were half as likely to be on the ‘decreasing’ path. Indian, Pakistani and Black African children were up to two times more likely to be on the ‘moderate increasing’ path whilst Pakistani, Black Caribbean and Black African children were up to three times more likely to belong to the ‘high increasing’ group.

The wealthiest children were least likely to be in the ‘moderate increasing’ BMI group and children of mums who smoked during pregnancy were up to two times as likely to belong to increasing BMI groups. Children with overweight mums were most likely to be on the moderate and high increasing paths.

Children on the moderate and high increasing paths were less likely to have regular family routines – they were more likely to skip breakfast or have non-regular bedtime schedules. Interestingly, however, no strong links emerged with some of the things more readily linked with childhood obesity such as sugary drinks and snacks, watching TV and lack of physical activity such as sports, the main focus of the newly published childhood obesity strategy.

Overweight factors

So it seems quite a large range of factors influence the likelihood of a child becoming overweight or obese over the first decade of their life. On top of this, being overweight or obese would also seem to point to a less happy and fulfilling early adolescence and a tendency to explore risky behaviours like smoking and drinking.

Although our research did not show a clear link with sugary drinks and snacks, there are nevertheless some compelling arguments for reducing the sugar intake of our children. These are not only related to problems of obesity, but to wider issues including the major issue of tooth decay and associated emergency hospital admissions. There is also increasing evidence of the ‘addictive’ nature of sugar with research suggesting that it stimulates a sort of ‘reward path’ in certain centres of the brain meaning that the more we have the more we want. It has been shown that people who reduce their sugar intake tend to crave it less.

Where sugar taxes have been introduced in other countries (Mexico, France, Denmark, South Africa amongst others), the intervention has been shown to help reduce the consumption of sugary drinks. As yet, there is no evidence that it helps reduce BMI and tackle obesity, but it’s argued it will take time for us to see an effect on whole populations.

Disadvantaged families

It is hard to predict how much impact the voluntary rather than mandatory reduction in sugar content of drinks and snacks agreed in the strategy will have. As for the sugar tax that will be introduced in two years’ time, there remain concerns that disadvantaged families more likely to purchase and consume sugary goods than their better off counterparts will be hardest hit. Policy makers will need to think hard about how any negative consequences of this might be counteracted.

Our research shows clearly that when it comes to the likelihood of a child becoming overweight or obese in the first decade of their life, there are many more influences than just sugar. Those influences are at play in families even before our children are born.

Helping pregnant women to stop smoking and maintain a healthy weight, making sure all young children have healthy eating and sleeping routines would seem to be key, together with targeted support for the ethnic and social groups identified as being most at risk.

Further information and resources

BMI development and early adolescent psychosocial well-being: UK Millennium Cohort Study is research by Yvonne Kelly, Praveetha Patalay, Scott Montgomery, and Amanda Sacker. The work, published in Pediatrics, is funded by the Economic and Social Research Council.

Media coverage

Photo credit: Kim Stromstad

Why poorer children are at greater risk of obesity

Obesity may be the biggest public health crisis facing the UK today. Levels have risen more than three fold since 1980. Being obese makes you vulnerable to a range of health risks. Being an overweight child makes it more likely you will become an obese adult. And you are much more likely to be an overweight child, if you come from a poor family. If current trends continue, half the population of Britain could be obese by 2050. Early intervention is the most effective way to break this cycle. And that requires a better understanding of why children become overweight. A new study by a team at the ESRC funded International Centre for Lifecourse Studies in Society and Health at UCL and LSE makes clear the scale of the problem and points to some crucial factors likely to lead less-well-off children to gain excess weight, as co-author Professor Yvonne Kelly explains.

A link between poverty and childhood obesity has been found in many developed countries. Intuitively, it seems likely this link is the result of poorer parents not being able to afford healthier food, like fruit, or outings involving exercise for their children. It could also be that those parents know less about healthy lifestyles and that they themselves eat less healthily and exercise less. But intuition is an insufficient basis for the scale of intervention required. This study is the first attempt to examine and compare in detail why children in poorer families are more likely to be overweight.

Our data comes from the Millennium Cohort Study (MCS). This tracks nearly 20,000 families from across the UK. We used measurements made when the children were aged 5 (when just entering primary school) and 11 (the point at which they leave primary school and are on the cusp of adolescence). We used standard definitions for ‘obese’ and ‘overweight’.

‘Stark’ link between poverty and obesity

The first thing we found was that the link between relative poverty and childhood obesity is stark. At age 5, poor children were almost twice as likely to be obese compared with their better off peers (6.6% of children from families in the poorest fifth of the sample were obese while the figure for the richest fifth is just 3.5%). By the age of 11, the gap has widened- nearly tripling (7.9% of the poorest fifth are obese; for the best-off, the figure is 2.9%).

Given that obesity is linked to the development of numerous chronic diseases and that there is evidence overweight and obese children are less likely to grow into economically and socially successful adults, this is a significant burden to be borne by the children of the less-well-off. And unless we can weaken the link our chances of reversing the overall obesity trend are much reduced.

Potential causes of that link

The MCS collects a broad range of data, allowing us to dig beneath these headline numbers to identify some of the specific ways in which relative poverty in childhood leads to an increased risk of obesity.

To measure the degree to which the mother followed a healthy life-style we looked at factors previously shown to be linked to the increased risk of obesity, such as whether the mother smoked during pregnancy, how long she breastfed for and whether the child was introduced to solid food before the age of four months.

We could also factor in the degree to which the mother was herself overweight or obese. To assess the impact of physical behaviour, we compared the frequency of sport or exercise, active play with a parent, hours spent watching TV or playing on a computer, journeys by bike and the time that children went to bed. We compared dietary habits via data on whether the child skipped breakfast and on fruit and sweet drink consumption.

Multiple factors

What we found was that a lot of these factors were relevant. Maternal behaviour in early childhood was certainly important. Markers of ‘unhealthy’ lifestyle here could mean as much as a 20% additional risk of obesity for a child. Measures of physical activity and diet were also relevant at both 5 and 11 years of age, as were early bedtimes and fewer hours in front of the TV or games console. Skipping breakfast and eating more fruit were factors at 5 but less significant at 11. Doing sport more frequently played a more important and protective role at age 11 than at age 5.

Further examination of the differences between the children aged 5 and aged 11 revealed that poorer children aged 5 were much more likely to gain excess weight up to age 11 than richer children. The earlier certain lifestyle factors can be challenged, therefore, the greater the chance of positive impact.

Multiple responses

Assuming that income inequality is not going to disappear, we can only tackle ‘inherited’ obesity via the lifestyle choices that tend to go with lower incomes. Early intervention with mothers clearly has huge potential. And evidence from our work suggests that this should start before birth or even conception. It is clear, too, that campaigns to encourage family physical activity and healthier diets would help.

The Government is already trying to persuade families to eat more healthily and take more exercise. But these efforts are widely targeted and their effectiveness only broadly assessed. Our analysis has already suggested better targeting. More research should be undertaken to narrow the aim and increase effectiveness still further.

Why are poorer children at higher risk of obesity and overweight? A UK cohort study is research by Alice Goisis, Amanda Sacker and Yvonne Kelly and is published in the European Journal of Public Health.

Photo credit: Playing on the computer,  John Watson