Tag Archives: Nutrition

Wheezing: Can breastfeeding for longer make a difference?

Public health bodies put a lot of effort into encouraging mothers to breastfeed, and for good reasons. Successive studies have shown breastfeeding has a range of health benefits, including a lower risk of wheezing illnesses, which can be linked to asthma. But which of these illnesses are most likely to respond? Is a breastfed child less likely to develop wheezing after age five, or age seven, for instance? Or is the protective effect mainly measurable only in younger children? Professor Maria Quigley from the National Perinatal Epidemiology Unit at the University of Oxford, along with colleagues at Oxford and UCL, has been looking at how and when breastfeeding is associated with wheezing.

Asthma is the most common chronic condition affecting children and young people in the UK. It’s the most common reason why children are admitted to hospital, and sadly each year a few still die from the condition. According to the British Lung Foundation three children in every hundred under the age of five have been diagnosed with asthma at some point; and by age 10 that figure rises to one in 10.

There’s no cure, and so the priority for public health bodies has been to understand the disease better, to manage it better and to learn more about the factors that can protect us from it. One such protective factor is breastfeeding: two recent pieces of research have shown there is a lower risk among breastfed children, but that the effect is stronger among the very young – both for asthma and for wheezing, which has many causes and which does not necessarily develop into asthma.

Childhood wheezing can follow a variety of patterns – it can set in early but clear up before adulthood, for instance, or it can start later but continue into later life. Some wheezing will start in childhood and will continue.

Millennium Cohort Study

We wanted to look at how breastfeeding might affect these different types, so we used data from the Millennium Cohort Study, which has followed the lives of almost 19,000 children born in the UK between September 2000 and January 2002. Their parents were interviewed when they were 9 months old, and again when they were 3, 5, 7 and 11 years.

Our study focused on just over 10,000 children who were seen at all of those points and who were the product of single as opposed to multiple birth. Mothers were asked whether they had tried to breastfeed, and for how long their children had been breastfed.

Among our sample, seven out of 10 children had been breastfed: a little more than one in ten of the study sample for less than a week; a fifth for between one and three weeks, just over one in six for three to six months and around a quarter for six to nine months.

We found that at age 9 months, 6.5 per cent of children had a history of wheezing. At age 3 years, 19.5 per cent had such a history in the past year. As the children got older, though, this proportion decreased – 16 per cent at age five, 11.8 per cent at age seven and 11.4 per cent at age 11.

Overall, 37 per cent of children had suffered from wheezing at least once between 9 months and 11 years. A little under a fifth (18.8 per cent) had wheezing at younger age which cleared up when they got older, while 6.2 per cent had wheezing which started later and 11.8 per cent had persistent wheezing.

Feeding and wheezing

When we looked at the association between breastfeeding and wheezing, we found the children who had been breastfed for longest were less likely to suffer from wheezing.

But this effect lessened with time. For example, those breastfed for six to nine months were less likely to wheeze between the ages of nine months and five years, but by the age of 11 this group had no significant advantage over those who were breastfed for less time.

What does our study tell us about the relationship between breastfeeding and wheezing? The picture is a complex one. There are many causes of wheezing and of asthma, and those causes change over time. So in order to draw firm conclusions about cause and effect, we would need a much more complex dataset. It would be interesting, for instance, to look at clinical information on children’s allergies or their lung function.

But what we can say is that age matters – in order to understand how breastfeeding affects the development of wheezing during childhood, we must take a longer and more nuanced view.

Breastfeeding And Childhood Wheeze: Age-Specific Analyses and Longitudinal Wheezing Phenotypes as Complementary Approaches To The Analysis Of Cohort Data is research by Maria Quigley (University of Oxford), Claire Carson (University of Oxford) and Yvonne Kelly (UCL). It is published in the American Journal of Epidemiology.

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.”

 

 

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.

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

Podcast: Play in new window | Download

Subscribe: Apple Podcasts | Android | RSS

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.

Slide5

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

BMI development and early adolescent psychosocial well-being

Research looking at how and when children become overweight is helping to shed new light on ongoing efforts by the Government and others to tackle the childhood obesity epidemic.

A team of researchers at the ESRC International Centre for Lifecourse Studies at UCL 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.

The research, published in Pediatrics, 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 (a main plank in the Government’s Childhood Obesity Strategy).

The research also shows that  influences are at play in families even before children are born and indicates that helping pregnant women to stop smoking and maintain a healthy weight, making sure all young children have healthy eating and sleeping routines may be key, together with targeted support for ethnic and social groups identified as being most at risk.

Lead researcher, Yvonne Kelly presented the findings at the Society for Longitudinal and Life Course Studies 2016 conference in Bamberg.

Giving children a better start

Child of our Time Editor, Yvonne Kelly will today be discussing why poorer children are more likely to be obese than their better off peers at a Big Lottery Fund event looking at how to give young children a better start in life.

She will be sharing recent research from the team at the ESRC International Centre for Lifecourse Studies at UCL looking at patterns of obesity in  young children using data from the Millennium Cohort Study.

The research finds that children from poorer backgrounds are the most likely to be obese and that the inequalities between richer and poorer children increase over time (between the ages of 5 and 11).

The research also identifies a number of other important factors associated with childhood obesity including smoking during pregnancy, mother’s obesity, skipping breakfast and irregular bedtimes.

The event, A Better Start ‘Focus on Diet and Nutrition is part of a programme of evaluation of the Lottery Funded ‘A Better Start’ initiative which aims to improve the life chances of babies and very young children by delivering a significant increase in the use of preventative approaches in pregnancy and first three years of life.

Yvonne is one of a group of experts and innovators in the field of child health and development to be invited to participate in the first of the initiative’s Learning and Development events. Other speakers include Eustace de Sousa, the lead for children, young people and families at Public Health England and Michael Hallsworth, director for Health at the Government’s Behavioural Insights Team, Chris Cuthbert, Director of the Big Lottery Development Fund and Celia Supiah, CEO of the charity Parents 1st.

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