More than 100,000 young Scots have obesity, global study finds

More than 100,000 children and young people in Scotland have obesity, according to University of Strathclyde researchers.

The Strathclyde team has participated in the biennial international report of the Active Healthy Kids Global Alliance (AHKGA), which assesses global trends in childhood physical activity in 49 countries. The ‘report cards’ provide rigorous but accessible assessments of the physical activity and health of children.

But the researchers believe the widespread use of bodymass index (BMI) to measure obesity in children could be underestimating by as much as half the true extent of the problem in Scotland – which is already one of the world’s most acute.

Globally, the study has found that physical inactivity has reached crisis levels, with many children around the world – including in Scotland – not moving enough to maintain healthy growth and development.

In Scotland, the research shows that levels of physical activity are well below recommendations in children and adolescents, while levels of exposure to screen are well above recommendations; levels of these behaviours in Scotland are amongst the worst in the world.

Professor John Reilly, of Strathclyde’s School of Psychological Sciences & Health, Scottish lead for AHKGA, also led a recent, separate study of obesity in Africa, involving 1500 primary schoolchildren across eight countries. This found a significant disparity between the level of children defined as obese by BMI – 9% - and those classed as obese by excessive fatness as measured by total body water. By the latter, more accurate measure – known as the deuterium dilution method - the level was 29%.

Professor Reilly said: “BMI is a straightforward and cost-effective way of measuring obesity in children. It has become widely-used in national surveys and in public health information but it is a very crude proxy measure.

“Large numbers of children and adolescents with an apparently healthy BMI for their age have an excessively high body fat content. Childhood obesity is at least twice as prevalent as reported in national surveys and official publications; in fact, more than 100,000 Scottish children and young people will have obesity at present.

“The deuterium dilution measure would be more costly and would take longer than BMI – three to four hours compared with 15 to 20 minutes for BMI but it would present us with a far more accurate picture of the scale of the problem. It needs to be properly studied and could be worth the consideration and investment.

“Our Africa study demonstrated the extent to which BMI underestimates the true prevalence of obesity. Combined with the Active Healthy Kids report, it suggests that there is no longer any room for complacency about childhood obesity anywhere in the world; urgent measures will be required to prevent and control the problem.”

Countries were ranked in 10 categories, including five for physical activity and others covering the support and environment for activity.

Scotland’s average grade was D+, placing it in the lower half of the rankings. This compared with C- for England, D for the United States and C for Nigeria. Slovenia had the highest rating of B, while China was ranked lowest on D-. Category scores for Scotland ranged from B for Organised Sport and Physical Activity to F for Sedentary Behaviour.

The report shows that modern lifestyles, including increases in screen time, the urbanisation of communities and the increasing automation of previously manual tasks, are contributing to this pervasive public health problem that must be recognised as a priority in Scotland and around the world.

Dr Mark Tremblay, President of the AHKGA and senior scientist at the CHEO Research Institute in Ottawa, said: “We all have a collective responsibility to address these cultural and social norms – particularly screen time – because inactive children are at risk for adverse physical, mental, social and cognitive health problems.

“This generation will face a range of challenges, including the impacts of climate change, increasing globalisation, and the consequences of rapid technological change. They will need to be purposely physically active in order to grow into healthy, resilient adults who can survive and thrive in a changing world.”

The Active Healthy Kids Global Alliance reports were launched at the Movement to Move Conference in Adelaide and published in the Journal of Physical Activity and Health. The Scottish report also included research from the University of Aberdeen.

The study led by Professor Reilly of obesity in Africa was published in the Bulletin of the World Health Organization and funded by the International Atomic Energy Agency.

Read the international report