Tag Archives: Overweight

Active children

Might population-wide increases in physical activity reduce socio-economic inequalities in the proportion of children who are overweight?

Just half of children in the UK achieve the World Health Organisation’s targets for daily activity, and in England the Government has set its own strategy to tackle this. But would increased physical activity lead to fewer children being overweight or obese? And would it help to address social inequalities in the proportion of children who are overweight? Research from Anna Pearce and colleagues at the UCL Great Ormond Street Institute of Child Health in London suggests more physical activity is unlikely to reduce the prevalence or inequalities in levels of overweight.

Childhood overweight is an important public health problem, with particularly high levels in children living in disadvantaged circumstances. Physical activity is an important determinant of childhood overweight. The World Health Organization (WHO) recommends children should undertake 60 minutes of moderate-to-vigorous physical activity every day. But for many families in England, as in other high-income countries, this is an aspiration rather than the reality.

The UK Government has identified a number of strategies to increase activity among children.  But the potential for physical activity initiatives to help children achieve a healthy weight, if scaled up at the population level, hasn’t previously been assessed. In our research, we focused on the WHO target, and on the likelihood that achieving this will reduce socio-economic differences in levels of overweight or obesity.

We wanted to know how hypothetical government interventions to increase activity might reduce the prevalence and inequalities in childhood overweight at age eleven. Could population-wide interventions, aimed at all, or targeted interventions with high-risk groups, have the greatest effect?

What, specifically, might happen to the prevalence and social distribution of childhood overweight if all children achieved the WHO’s target of 60 minutes’ activity per day? What if we are only able to achieve smaller increases in activity than those required to meet the WHO target?

In our study, 27% children were overweight at age eleven. We found that hypothetical universal interventions to increase physical activity could lead to moderate reductions in this. For example, if 95 per cent of children met the target of 60 minutes of activity per day, the prevalence of overweight (including obesity) would drop to 22 per cent. But more realistic scenarios, in which interventions led to more moderate improvements in physical activity levels (of only a few minutes each day), would achieve only small reductions in overweight within the population.

Children from the most affluent backgrounds were less likely to be overweight  – around one in five children in the top fifth of household incomes were overweight or obese at 11y, compared to one in three among those in the bottom fifth of household incomes. Our analysis suggested these stark social differences in overweight are unlikely to be reduced through meeting the WHO physical activity target. This is partly because children from the highest income group had the lowestlevel of daily activity, with a median of 59 minutes’ moderate to vigorous activity compared 62 minutes for the lowest fifth of the income range.

Even more intensive intervention scenarios, given only to high-risk families (for example those who were overweight or obese at an earlier age, or those living in disadvantaged neighbourhoods), appeared unlikely to address the stark social inequalities experienced by this cohort of children.

Activity targets

The WHO’s physical activity targets are ambitious and, if achieved, are likely to benefit children’s health and wellbeing in a multitude of ways. However our findings suggest that if the Government is serious about supporting children and families – particularly those from poorer backgrounds – to maintain healthy weights, it needs to look elsewhere.

We need, therefore, to know more about how other types of initiatives to reduce childhood overweight might work. Research which aims to inform this debate should look not just at activity levels but also at environmental factors that influence diet, such as taxes on high-sugar foods and foods provided in early-years settings.

What if all children achieved WHO recommendations on physical activity? Estimating the impact on socioeconomic inequalities in childhood overweight in the UK Millennium Cohort Study, by Anna Pearce, Steven Hope, Lucy Griffiths, Mario-Cortina-Borja, Catherine Chittleborough and Catherine Law, is published in the International Journal of Epidemiology, 2019, 134–147.

Anna Pearce is based at the University of Glasgow but carried out this work out in her previous position at the UCL Institute of Child Health.

Steven Hope, Mario Cortina-Borja, and Catherine Law are based at the Population, Policy and Practice Research and Teaching Department, UCL Great Ormond Street Institute of Child Health, London, UK.

Lucy Griffiths is based at Swansea University but carried out this work out in her previous position at the UCL Institute of Child Health…

 Catherine Chittleborough is at the School of Public Health, Robinson Research Institute, University of Adelaide, Adelaide, SA, Australia.

This blog is based on independent research funded by the National Institute for Health Research (NIHR) Policy Research Programme (Children’s Policy Research Unit). The views expressed are those of the author(s) and not necessarily those of the NIHR or the Department of Health and Social Care.

 

Off the scales: time to act on childhood obesity

By 2050, it is said that obesity could cost the NHS almost £10 billion a year, with the full economic cost rising from around £27 billion today to £50 billion by then. Today, the Centre for Social Justice (CSJ) publishes its report, Off the scales: time to act on childhood obesity. It calls on the Government to put prevention, health, inequality and cross-departmental collaboration at the heart of its efforts to tackle childhood obesity, drawing particular attention to the need to address the question of why poorer children are at ever greater risk of being obese. It’s a question researchers at the ESRC International Centre for Lifecourse Studies at UCL, including our editor Yvonne Kelly, have been among the first to address.

There have been numerous major studies on childhood obesity over the past 10 years, many of which have shown the links with poverty. But our research looks specifically at why children from disadvantaged families are significantly more likely to be obese than their better off peers.

To examine this as robustly and rigorously as we could, we used data from the Millennium Cohort Study (MCS) which has tracked the lives of nearly 20,000 children from across the UK since the turn of the century. Using a range of measurements taken when the children were aged 5 and 11 together with detailed information about their backgrounds and family circumstances, we were able to demonstrate just how key poverty was in respect of their obesity.

At age 5, poor children were almost twice as likely to be obese compared with their better off peers. By the age of 11, the gap had nearly tripled.

Knowing as we do that obese children are less likely than their peers to grow into economically successful adults and that obesity is clearly linked with a range of chronic diseases, it’s reasonable to say that for these children, the future is far from bright. From a policy perspective it is also clear that unless the gap between rich and poor children can be closed the chances of reducing the overall obesity trend, as the Government states it is committed to doing, are pretty slim.

How is poverty linked to obesity?

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

To examine this question of whether a parent’s own lifestyle might have a role, 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 a mother was herself overweight or obese and assess children’s physical behaviour, such as how often they exercised, played and how many hours they spent watching TV or playing on a computer, and the time that they went to bed. We looked at whether the child skipped breakfast, how much fruit they ate and how often they had sweet drinks.

A lot of these factors were relevant. A mother’s behaviour when her child was very young was certainly important. Markers of an ‘unhealthy’ lifestyle here could mean as much as a 20 per cent additional risk of obesity for a child.

Obese and overweight children living in poor families were more likely to have mothers who did not breastfeed or breastfed for a shorter duration, who introduced solid foods early in infancy, who smoked during pregnancy, and who were overweight or obese. The poorest children were also more likely to spend more time watching TV and using a PC (and so have greater exposure to food and drink advertising), experience later and more irregular bedtimes, do less sports and be more physically inactive, engage less in active play with their parent, live in an area without a playground, and not have breakfast every day.

5-year-olds from poorer families were also much more likely to gain excess weight up to age 11 than richer children, leading us to conclude that the earlier certain risk factors can be challenged and the appropriate support provided for the least well off families, the greater the chance of positive impact on the risk of obesity and in a reduction in inequality.

Pathways to obesity

More recently we have identified four BMI trajectories for children. The good news is that 80 per cent of them are on a stable path where, on average, from when they’re born through to age 11, they are not overweight.

There is a small group of children who are obese at age 3 but then join the stable group by age 7. We call them the ‘decreasing’ group. There is a ‘moderate increasing group’ (13.1 per cent) where children are not overweight at age 3 but whose BMIs increase throughout childhood into the overweight (but not obese) range. Finally we have a ‘high increasing’ group of children (2.5 per cent) who are obese at age 3 and whose BMI continues to increase.

From an inequality perspective, what’s most striking here is that the wealthiest children are least likely to be in the ‘moderate increasing’ BMI group whilst the poorest children are more than twice as likely to be on the high increasing path.

Today’s CSJ report agrees with our analysis that early intervention is key and, in line with it, proposes three key early years intervention opportunities to ensure children get the healthiest start possible before they reach primary school age.

The report acknowledges that the Government is already trying to persuade families to eat more healthily and take more exercise. But it has joined a body of voices critical of the Childhood Obesity Plan, which, it believes, “fails to put reducing inequality as a goal … despite acknowledging that the childhood obesity burden falls hardest on the poorest children.”

Certainly our body of evidence indicates that policy makers need to acknowledge and address inequality as a root cause of obesity. Doing something about the structural factors in people’s lives is what is needed rather than ‘tinkering around the edges’ of the problem.

Today the CSJ asks why there are disproportionately high levels of obesity, particularly childhood obesity, in our most deprived communities. Our research has gone some way to answering that question, and makes it clear that there is no simple one-stop shop solution.

Obesity is caused by a combination of environmental, biological, cultural and psychological factors, where one factor does not dominate and yet our obsessional search for the ‘one thing’ that can tackle obesity continues. If the Government is going to reduce obesity rates, it will indeed, need to introduce multiple bold measures in tandem across the entire ecosystem and recognise that success may only be measurable after a few years.

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

BMI Development and Early Adolescent Psychosocial Well-Being: UK Millennium Cohort Study is research by Yvonne Kelly, Praveetha Patalay, Scott Montgomery and Amanda Sacker and is published in Pediatrics

An equal start: longitudinal evidence to support children’s healthy development

Using longitudinal evidence to support children’s healthy development and give them an equal start in life is the subject of our editor Yvonne Kelly’s keynote address at the Growing up in Ireland Annual Conference in Dublin today.

Her talk discusses findings from the most recent of the British ‘birth ‘ cohort studies – the Millennium Cohort Study that have so far informed policy development. They include work by researchers at the ESRC Centre for Lifecourse Studies where Yvonne is based on alcohol consumption during pregnancy, breastfeeding and the introduction of solid foods, the physical punishment of children , childhood obesity, reading to children in the early years, and sleep patterns throughout childhood.

She will also share work with the potential to inform future policy challenges such as young people’s drinking, social media use and mental health.

Ahead of her talk, she said:

“It is well established that what happens in the early years of life has long-lasting consequences for health and social success across the lifespan. Stark social inequalities in children’s health and development exist and emerge early in life. It is therefore crucial to identify potential tipping points and opportunities for intervention   during childhood with the potential to affect change and improve life chances.”

 

 

Don’t let the kids get jet-lag: why regular bedtimes are key to a happy healthy childhood

The very best of sleep medicine and research is being presented at the World Sleep Congress in Prague this week. Among that research are findings from work by Child of our Time Editor, Professor Yvonne Kelly and colleagues at the ESRC International Centre for Lifecourse Studies. They have been trying to find out what it is about sleep that matters most when it comes to giving children the best possible start in life. Here Yvonne explains what they have found to date and why regular bedtimes are key to a healthy happy childhood.

What happens in the early years has profound implications for what happens later on in life. Thousands of research papers, many of them using the wonderful rich data in the British Birth Cohort studies, have documented the enduring impacts of the way we live our lives as children on how we fare later on. Children who get a poor start in life are much more likely to experience poor outcomes as adults, whether that’s to do with poor health or their ability to enjoy work and family life later on.

So what has all that got to do with getting enough sleep as a toddler you might ask? Well our research shows it is one of a number of important factors related to getting children off to the best possible start in life and here’s why.

Recommended sleep

The National Sleep Foundation recommends that toddlers should get around 11 to 14 hours sleep every day. For 3-5 year-olds, the recommendation is 10-13 hours and it suggests 9-11 hours for children once they’re at primary school. But is it all about the number of hours sleep children get, or is there more to it than that? Those are the questions we have been addressing in our research into children’s sleep and how it ties in with how they get on at home and at school across the first decade of their life.

Digging into one of those studies mentioned earlier, the Millennium Cohort Study, which has followed the lives of some 20,000 children since the turn of the century, we found that it’s not just the number of hours a child sleeps that matters, but also having consistent or regular bedtimes.

First we looked at the relationship between regular and irregular bedtimes and how the children got on in a range of cognitive tests. The results were striking. Children with irregular bedtimes had lower scores on maths, reading and spatial awareness tests.

Parents who took part in the MCS were asked whether their children went to bed at a regular time on weekdays. Those who answered “always” or “usually” were put in the regular bedtime group, while those who answered “sometimes” or “never” were put in the irregular bedtime group.

Interestingly, the time that children went to bed had little or no effect on their basic number skills, and ability to work with shapes. But having no set bedtime often led to lower scores, with effects particularly pronounced at age three and the greatest dip in test results seen in girls who had no set bedtime throughout their early life.

The key to understanding all this is circadian rhythms. If I travel from London to New York, when I get to there I’m likely to be slightly ragged because jet lag is not only going to harm my cognitive abilities, but also my appetite and emotions. That’s for me, an adult. If I bring one of my children with me and I want them to do well at a maths test having just jumped across time zones, they will struggle even more than I will. The body is an instrument, and a child’s is especially prone to getting out of tune.

The same thing happens when children go to bed at 8 p.m. one night, 10 p.m. the next and 7 p.m. another — we sometimes call this a “social jet lag effect.” Without ever getting on a plane, a child’s bodily systems get shuffled through time zones and their circadian rhythms and hormonal systems take a hit as a result.

Bedtimes and behaviour

Having established the importance of sleep to a child’s intellectual development, we turned our attention to the relationship between regular bedtimes and their behaviour.

At age 7, according to parents and teachers, children in the MCS who had irregular bedtimes were considerably more likely to have behaviour problems than their peers who had a regular bedtime. In addition, the longer a child had been able to go to bed at different times each night, the worse his or her behaviour problems were. In other words the problems accumulated through childhood.

One really important piece of good news was that we found that those negative effects appeared to be reversible, so children who changed from not having to having regular bedtimes showed improvements in their behaviour. There seems to be a clear message here that it’s never too late to help children back onto a positive path and a small change could make a big difference to how well they get on. Of course, the reverse was also true so the behaviour of children with a regular bedtime who switched to an irregular one, worsened.

Bedtimes and obesity

In a follow up study, which looked at the impact of routines including bedtimes on obesity, we reported that children with irregular bedtimes were more likely to be overweight and have lower self-esteem and satisfaction with their bodies.

In fact, of all the routines we studied, an inconsistent bedtime was most strongly associated with the risk of obesity, supporting other recent findings which showed that young children who skipped breakfast and went to bed at irregular times were more likely to be obese at age 11.

Even children who ‘usually’ had a regular bedtime were 20 per cent more likely to be obese than those who ‘always’ went to bed at around the same time.

So we have a body of robust evidence now that shows very clearly that regular bedtimes really matter when it comes to a child’s health and development over that important first decade of their life.

Providing that evidence in the form of advice to parents and all those caring for young children alongside recommended hours of sleep could make a real difference, helping protect our children from ‘social jet-lag’ and getting them off to a flying start instead.

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.

Tackling the childhood obesity epidemic: Can regular bedtimes help?

Nearly one in five 10 and 11-year-olds in England is obese, according to NHS figures. With childhood obesity posing not just a nationwide, but a worldwide health threat, public health researchers around the globe are striving to establish which aspects of a young child’s life might set them on a path to being obese later on. Associate Professor Sarah Anderson from The Ohio State University College of Public Health and colleagues from University College London outline the first research to try to disentangle the role of children’s routines and behaviour at age 3 on obesity at age 11 and show that bedtime routines and learning to manage emotions really do matter.

The UK’s Chief Medical Officer Professor Dame Sally Davies has warned that the health of millions of children is in jeopardy and is concerned that being overweight is becoming the norm. She fears half the population could be obese by 2050 at a cost of billions of pounds to the health service and wider economy.

The latest statistics highlight a stark contrast between the wealthiest and poorest families, with childhood obesity rates in the most deprived areas more than double those in the most affluent areas.

Despite the publication in August 2016 of the Government’s long-awaited childhood obesity strategy, charities and health organisations remain highly critical, describing it as a watered-down effort that puts business interests ahead of those of public health. Even the recent introduction of the so-called ‘sugar-tax’ on soft drinks has been met with scepticism in some quarters.

To help inform public health strategies going forward, our researchers looked at the bedtime, mealtime and tv/video routines of very young children and their emotional and behavioural development to see if, at this early stage, it is possible to identify those most at risk of becoming obese.

The study includes information on nearly 11,000 children collected through the UK Millennium Cohort Study (MCS). When the children were three, their parents reported whether children always, usually, sometimes, or never or almost never had a regular bedtime and mealtime, and the amount of television and video they watched each day.

They were also asked a series of questions about the child’s behaviour during the previous six months. Questions were about how children cope with emotions and their persistence and independence in play, including how easily the child became frustrated and whether they sought help from adults when faced with a difficult task. This was to get an idea of how well the child was able to ‘self-regulate’ their behaviour in these areas.

Regular routines

Children with regular bed and mealtimes and who watched less television were better able to control their emotions than their peers with less regular and consistent routines.

At 11-years-old, 6.2 per cent (682) of the children in the MCS were obese, with obesity more common in lower income and less educated families.

Of the routines we studied, inconsistent bedtime was most strongly associated with the risk of obesity, supporting recent findings by our UCL colleagues which showed that young children who skipped breakfast and went to bed at irregular times were more likely to be obese at age 11, stressing the importance of adequate sleep for preventing childhood obesity.

Even children who ‘usually’ had a regular bedtime were 20 per cent more likely to be obese than those who ‘always’ went to bed at around the same time.

Regular bedtimes and obesity

Surprisingly, toddlers with irregular meal times had a lower risk of obesity at age 11. Once other routines were factored in, television viewing was not related to obesity, although it is important to note that computer use was not taken into account, and the media environment for young children today is different than it was when children in MCS were young.

There was also a clear link between lower levels of emotional self-control in early childhood and obesity later on. Children with poor emotion regulation at age 3 were over 50 per cent more likely to be obese when studied at age 11.

Children’s level of persistence and independence was not linked to later obesity, however, and it is possible that this could be explained by the relative immaturity of the parts of the brain responsible for a child’s cognitive compared with their emotional development at this young age.

Strongest risk

Our study is the first to look at the relationship between a child’s routines, their ability to regulate their emotions and behaviour and how these factors work together to predict obesity.

The two strongest risk factors for obesity were irregular bedtime and a poor ability to control emotions and these were completely independent of each other. In other words, the link between bedtimes and obesity could not be explained away by a child’s inability to regulate their emotions.

There is a need to look more closely at the timing and regularity of children’s mealtimes and how they impact obesity later on, as we think there may be a lot more factors at play than we have considered here. We also need to better understand how the development of emotional and cognitive self-regulation interacts with metabolic, behavioural and social pathways to obesity.

However, our study supports previous research showing that children’s emotional regulation develops within a family context which includes routines.

One message from our study is crystal clear. To be effective, obesity strategies must target early childhood, and must find a way to support parents, especially those from the most deprived areas, to introduce and maintain consistent bedtimes and other home routines, as well as help children regulate emotions and respond to stress.

Another key message is that one size does not fit all. There is a lot going on in children’s lives that is important for their health and development. Saying that, it would seem that getting our children to bed at the same time every night could be a simple, cost-effective tool in the tool-kit to get them off to a good start and maybe in the larger battle against obesity.

Self-regulation and household routines at age three and obesity at age 11: Longitudinal analysis of the Millennium Cohort Study is research by Sarah Anderson from The Ohio State University College of Public Health; Amanda Sacker and Yvonne Kelly from University College London and Robert Whitaker of Temple University, Philadelphia.

Giving children the best possible start – what matters most?

Child of our Time Editor Yvonne Kelly spoke to a 500-strong audience of politicians and professionals in Gothenburg recently on what matters when it comes to giving children the best possible start in life.

Yvonne was the keynote speaker at the conference hoping to identify the best strategies for making Gothenburg a more equal and socially sustainable city.

Yvonne, Professor of Lifecourse Epidemiology at the ESRC International Centre for Lifecourse Studies at UCL  explained which factors are most closely linked with a child’s health and well-being and presented her research findings on children’s verbal skills, behaviour, bedtimes, reading and obesity.

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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Better start for children

Giving children the best possible start in life is the topic of a keynote talk today by our editor Yvonne Kelly.

Yvonne will be presenting a range of new evidence from the ESRC International Centre for Lifecourse Studies  to politicians, business leaders, and other professionals and key decision makers at an event discussing how Gothenburg can be made an equal and socially sustainable city.

Yvonne will talk about the factors which are most closely linked with a child’s health and well-being and present findings on children’s verbal skills, behaviour, bedtimes, reading and obesity. She will make the case that signs of social inequalities are evident early in a child’s life and that it is important to intervene early to tackle those inequalities.

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.

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Photo credit: Kim Stromstad