Evidence
Alert

Schoolchildren who switch to walking or cycling may have a healthier body weight

Children who walk or cycle to school may have a healthier body weight than those who arrive by car. A new study followed more than 8,000 schoolchildren over a period of years. The findings showed that even using public transport instead of taking the car led to a reduction in body fat.

It is widely accepted that physical activity helps people of all ages stay at a healthy weight. Walking or cycling (active travel) to school is likely to help children achieve this but, before this study, there was a lack of adequate evidence.

As children get older, they become more independent and often have more choices about how they get to school. Researchers found that children who switched to walking and cycling to school between the ages of 7 and 14 had healthier body weights than those who continued to travel by car. The findings also suggest that the beneficial effects of walking or cycling may be greater for children from the most deprived areas.

Obesity is a major public health problem in the UK. More than one in five children in the last year of primary school are overweight and as a result are likely to have poorer physical and mental health.

This research underlines the importance of encouraging active travel. This means providing safe and effective infrastructure to encourage people to walk, cycle, or use public transport. Finding ways of supporting children and families from lower income households to walk or cycle could help these groups overcome some of the health inequalities they face. 

Further information on healthy weight is available on the NHS website.

What’s the issue?

Obesity is becoming more common in the UK, particularly among disadvantaged groups. Children living in the most deprived areas are more than twice as likely to be overweight than children living in the least deprived areas. 

Being obese or overweight is linked to poor mental health. Children living with obesity are more likely to be overweight as adults. This increases their risk of medical conditions such as diabetes and heart disease, of disability, and early death.

Physical activity can help children stay at a healthy weight. But less than half of children and young people meet the recommended level of physical activity of an hour each day. 

Getting around by walking, cycling and other active methods of transport is one way of increasing physical activity. The choices and options of transport available to children change as they grow up and become more independent. Options such as walking are available to children from a range of backgrounds and may offer a way of combating health inequalities. 

While it seems likely that active travel to school could help children maintain a healthy weight, there is a lack of adequate evidence. The researchers wanted to look for links between how children and young people travel to school and their weight over the long-term. 

What’s new?

The research team used the UK Millennium Cohort Study to follow the same children over 8 years. They gathered data on 8,432 children at the ages of 7, 11 and 14.

Researchers asked families and caregivers whether their child usually travelled to school by car or other vehicle (including taxi), public transport, bicycle, or walking. They used two ways of measuring how healthy the children’s weight was: the percentage of body fat, and Body Mass Index (BMI), which takes into account weight and height.

They also analysed information about other factors that may influence the relationship between weight and travel type. This included data on sex, ethnicity, socioeconomic background, whether children ate breakfast, and other physical activity. 

More than half the children switched their way of getting to school at least once. At age 14, one in four (26%) went by car, one in three (35%) by public transport, and the largest group (39%) walked or cycled.

Children who switched to active transport between the ages of 7 and 14 had healthier body weights than those who continued to travel by car. A greater number of children from lower-income households walked or cycled to school. The data suggested that these children benefited more from the switch than children from wealthier backgrounds, but the difference was slight.  

Compared with continuing to use private transport, the group which switched to walking or cycling had: 

  • less body fat (0.55% less on average)
  • a lower BMI (0.21 kg/m² less on average

Switching to public transport was associated with slightly less body fat (average reduction of 0.43%) but no meaningful reduction in BMI.

The researchers note that active travel is only one potential route to a healthy weight. Other lifestyle changes (switching to eating breakfast every day or taking part in sport five or more days/week) were linked to greater reductions in BMI and body fat. But they say that active travel is a simple and widely available lifestyle change. 

Why is this important?

This research adds to evidence advocating for the health impacts of active travel. In addition to the environmental benefits, these findings suggest that children can achieve a healthier body weight by switching to physically active forms of travel. 

Disadvantaged children may benefit more than others from his lifestyle change. Interventions to increase the amount of active travel these children do could help them overcome the health inequalities they face as a result of their socioeconomic background. 

What’s next?

The researchers say that further evidence is needed on how best to encourage people to use active modes of travel rather than using the car. 

This will require action at a number of levels. School policies to discourage driving would help, as would safer cycle routes. Policy changes could include expansions to London’s Congestion Charge scheme, Low Emission Zones in other places like Birmingham, and the implementation of Low Traffic Neighbourhoods. 

Ambitious thinking is needed to drive and support positive changes in travel behaviour, the researchers conclude.

You may be interested to read

The full paper: Laverty AA, and others. Associations of active travel with adiposity among children and socioeconomic differentials: a longitudinal study. BMJ Open 2021;11:e036041 

Sustrans, a charity aiming to make a UK-wide network of traffic-free paths.  

Bikeability, the UK government's cycle education programme which offers local cycle training through schools and providers. 

Living Streets, a charity providing walking resources and information. 

A paper from the same research group that explored the health benefits of getting around using methods other than by car: Patterson R, and others. Associations between different methods of commuting and death from any cause, cardiovascular disease and cancer, and cancer incidence. The Lancet 2020;4:5

 

Funding: This research was funded by the NIHR School for Public Health Research and an NIHR Research Professorship. 

Conflicts of Interest: The study authors declare no conflicts of interest.

Disclaimer: NIHR Alerts are not a substitute for professional medical advice. They provide information about research which is funded or supported by the NIHR. Please note that views expressed in NIHR Alerts are those of the author(s) and reviewer(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

Commentaries

Study author

The results add to lots of other evidence on the health benefits of walking, cycling and public transport. 

In particular, our findings add evidence that changing travel mode at a key period in a young person’s life can have health benefits. We know that from age 7 to 14 there are lots of big changes in children’s lives, including changing schools and the likely onset of puberty. But the results tell us that what is a simple change for many people can have demonstrable benefits. 

It may also be that the beneficial effects of switching to walking or cycling are greater for children from lower-income households. This is important if true, because lots of existing interventions tend to give more benefit to more advantaged people.

I hope that all of this evidence will encourage individuals to consider changing their travel behaviours. But more importantly, there is a big role for local and national governments to make it easier for people to walk and cycle. There has been a real focus on this throughout the COVID-19 pandemic, and more cycle lanes and infrastructure are being built, so hopefully this can continue.

Anthony Laverty, Lecturer in Public Health, Department of Primary Care & Public Health, Imperial College London 

World Obesity Federation 

This study shows a moderate reduction in BMI in a key moment of a person’s life, especially since the evidence is now clear that children with obesity have a significantly higher risk of obesity as adults. Regular physical activity is of high importance for children’s overall physical and mental health. Moreover, switching to active transport also has other benefits, including reducing environmental impact.

However, when focusing exclusively on obesity and BMI it is vital to understand that physical activity is just one of many factors at play with obesity. Being physically active might modestly reduce BMI in children but it is just part of an overall approach. Unless we also act on availability and affordability of nutritious food (and lack of restrictions on ultra-processed foods), acknowledgement of the genetic components of the disease, and impact of stigma and mental health, weight loss will not be sustainable and will continue to be a major challenge at the population level.” 

Olivia Barata Cavalcanti, Director of Science and Education, World Obesity Federation 

Parent and GP 

It is perhaps common sense that an active mode of travel to school may be beneficial. As a GP and a mum on the school run for many years, I can say for certain that choice of travel mode is dependent on a huge range of factors including the number of children, their various ages and whether they are at different schools, plus any disability in parent, child or both. Then there is access to parking, care-giver split in the household, perceptions of road and physical safety and of risk of air pollution. The length of the school journey and the need for parents or care-givers to get to work on time obviously matter. 

It is likely that parents choose the most convenient, safest, and least expensive mode of travel for their family situation. These findings will only change behaviour if they influence national policies and impact on infrastructure, rather than relying on decision-making by individual families or schools.

Previously as a school governor, I tried for several years to encourage more active travel to my children’s primary school. I have learned that public health systems, local councils, transport policymakers, educators, and families would have to come together to find ways to influence and change travel mode choice for a sustainable and healthier future.

Jasjit Atwal, GP, Hucknall Road Medical Centre

Member of the public 

I am stunned that hardly any children under seven walk or cycle to school. When I went to school in the 70’s we all did!

This work makes me realise just how important it is to keep active and how hard that can seem in life.

More cycle paths, and nice walking routes with things like zebra crossings would help. As would Government campaigns to get children walking to school.

Rachel Gerrard, Public contributor, Hitchin