Children are growing taller, but only because they are becoming fatter, research shows.
A study by the University of Oxford shows that 11-year-old girls are almost an inch taller than those just over a decade ago, while boys of the same age are half an inch taller.
Researchers said the trend was being fuelled by childhood obesity, with much of their growth spurt taking place during the pandemic.
Being overweight or obese causes hormonal changes, which accelerate children’s development. Obese children grow faster, so they tend to be taller than their peers who are at a healthy weight.
However, they also have a greater risk of conditions such as heart disease and diabetes later in life.
Children were taller in poorer areas
The research showed the sharpest increases in height were in the most deprived areas, while rates of obesity rose. When the figures were standardised, the growth of girls in poor areas increased twice as much as those in wealthy parts.
Andrew Moscrop, a researcher from Oxford’s Nuffield Department of Primary Care Health Sciences, said: “It might look like a simple good news story, as on average children in Britain are getting taller.
“But in fact, it’s a complex bad news story, because this trend is mostly due to height changes among poorer children, and these are being driven by increases in obesity prevalence, which are themselves driven by unfair determinants of health.
“Children in poorer areas are exposed to more unhealthy food outlets and fewer healthy food sources, while they have less access to outdoor spaces and safe streets for exercise.”
Overall, the average height of 11-year-old girls went from 145.75cm (just under 4ft 8in) in 2008-9 to 148cm by 2020-21.
Meanwhile, boys saw a rise from 145cm to 146.5cm over the same period.
‘Remarkable’ growth during the pandemic
The figures show a “remarkable” rise in the average height of children during the pandemic.
Researchers said the jump reflected a rise in obesity prevalence, as children ate less healthily and took less exercise during lockdown.
Among 11-year-old girls in England, average height jumped from 146.6cm to 148cm between school years 2019-20 and 2020-21, while prevalence of overweight and obesity among this age group increased in the same period from 35.2 to 40.9 per cent.
The increase in average heights from 2019-20 to 2020-21 was 1.3 cm in boys and 0.7 cm in girls, compared with rises of 0.7cm seen between 2009 and 2019, researchers found.
For five-year-olds, average height increased between 2019-20 and 2020-21 by 0.5 cm in boys and 0.4 cm in girls, more than the 0.2cm rise seen from 2009 to 2019.
However, researchers also highlighted some poor record-keeping during the pandemic, which might explain the patterns, some of which levelled out.
Researchers said their interest in children’s heights was prompted by reports in 2023 claiming that children were shrinking during the pandemic, which was found not to be the case.
However, the research suggests heights have now started to fall.
Records for 2022-23 show five-year-old girls and boys were at least half a centimetre shorter than they were in 2021-22, with a similar dip seen among 11-year-old girls.
Child Measurement Programmes routinely measure the height and weight of every child during their first year of state education in Britain.
In England, approximately 600,000 children aged between four and five are measured annually, while fewer are measured in Scotland (50,000 to 55,000) and Wales (30,000 to 35,000).
Children in England are also measured between the ages of 10 and 11, in their final year of primary education.
