British children are getting taller – and obesity may be the cause

British children are not getting shorter, despite claims to the contrary. In fact, they are getting taller.

But this is not good news. When my colleagues and I analysed national data on child height, we found that the trend is largely explained by rising childhood obesity and widening inequalities.

Claims that British children are becoming shorter than their European peers have circulated widely in recent years. These concerns were often linked to suggestions that poor diet and food insecurity were harming children’s growth. But when we examined the available data, we found that many of these claims relied on incomplete or misinterpreted evidence.

To understand what was really happening, we analysed height data from the child measurement programmes that operate across Britain. These programmes measure the height and weight of children in their first year of state school and again in their final year of primary education. In England alone, around 600,000 children aged four to five are measured each year. Children aged ten to 11 are also measured – another 600,000 pupils annually.

Together, these programmes create an unusually rich dataset. The annual measurement of more than a million children provides one of the most comprehensive sources of child growth data anywhere in the world. Using freedom of information requests and official releases, my colleagues and I obtained all available height data from these programmes.

The pandemic effect

When we analysed the data we found two surprising results.

First, child height increased dramatically during the COVID pandemic. At first we suspected this might be a quirk of the data. School closures disrupted measurement programmes, meaning children were often measured later than usual – and therefore at slightly older ages.

But even after correcting for the children’s ages at measurement, the increase remained. The rise in height during COVID was seen among boys and girls, across levels of deprivation and most ethnic groups and localities.

Average height of 11-year-olds in England

Why did child height increase during COVID? The answer appears to be obesity. Obesity causes hormonal changes that accelerate child growth, meaning that obese children often grow taller faster than their healthy-weight peers.

Lockdowns are already known to have led to a surge in childhood obesity. Our analysis suggests they also led to a surge in child height. Among girls aged 11 in England, average height increased from 146.6cm to 148cm between the 2019–20 and 2020–21 school years, while the proportion of overweight or obese children in this group rose from 35.2% to 40.9%.

The second surprising finding was that even before COVID, average child height in Britain had been gradually increasing. At first this appeared encouraging – particularly because the largest increases were seen among children living in deprived areas.

But again the explanation appears to be obesity.

In England’s most deprived areas, the average height of 11-year-old boys increased by 1.7cm – from 144.4cm to 146.1cm – between 2009–10 and 2023–24. Over the same period, the proportion of children who were overweight or obese increased from 37.7% to 43.3%.

Similar patterns can be seen in Scotland. Childhood obesity rates have increased in deprived areas while declining in more affluent ones, widening the health gap between them.

Height gains linked to childhood obesity do not signal better health. Obese children often enter puberty earlier and stop growing sooner, and they face increased risks of chronic diseases such as diabetes and heart disease later in life.

The role of inequality

These trends reflect deeper inequalities. While everyone’s access to outdoor spaces was restricted during the COVID lockdowns, poorer families face many other pressures that drive weight gain – and those don’t go away.

Children in deprived areas are more exposed to unhealthy food outlets and have fewer healthy food sources. They often have less access to safe outdoor spaces where they can play and exercise safely, and children’s services have been cut back – most severely in the areas that need them most.

British children may not be shrinking, but their growth is not good news.

Child height can no longer be assumed to signal good health. In Britain today, rising average height among children reflects rising childhood obesity and deepening inequality. If we want children to grow up healthy, we need to address child poverty, inequality and the environments children grow up in.

Andrew Moscrop does not work for, consult, own shares in or receive funding from any company or organisation that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.