How has children’s health in the UK changed over the past 100 years?

Children today have better nutrition and access to clean water, sanitation and medical care than their counterparts a century ago. These improvements have led to falling rates of infectious diseases, and infant and child mortality – but new health concerns are emerging, including childhood obesity.

The physical health of British children has improved substantially over the last century. While there had already been many improvements in children’s health before 1926, both infant and child mortality rates were much higher 100 years ago than they are today. The average child was also both shorter and lighter than their modern-day equivalent.

The advances that have occurred since 1926 reflect changes across many different aspects of children’s lives. Today, they are better nourished, exposed to fewer life-threatening infections and able to access better medical provision. But children in 2026 are also at greater risk of obesity and associated health conditions (see, for example, Iacobucci, 2024).

This article exploring children’s health over the last 100 years is part of a series to mark the centenary of the Economic History Society.

What has changed in children’s physical health?

As child health specialists explained half a century ago, ‘a child’s growth rate reflects… [their] state of health and nutrition; and often, indeed, [their] psychological situation also’. These authors added that ‘the average value of children’s heights and weights reflects accurately the state of a nation’s public health and the average nutritional status of its citizens, when appropriate allowance is made for differences, if any, in genetic potential’ (Eveleth and Tanner, 1976, and second edition, 2010).

Although these experts were primarily concerned with variations in the average heights of contemporary populations, economic historians have used their insights to measure changes in the average heights and weights of children over time.

In the 1920s, the average height of children aged five and a half years old in 12 local authority areas was approximately 105cm (Floud et al, 2011). In 2025, in England, the average height of five-year-old children was approximately 110cm (Office for Health Improvement and Disparities, 2025a). In other words, children who were six months younger were 5cm taller.

Economic historians have also sought to estimate changes in the prevalence of stunting in childhood (when a child’s height for their age is significantly below the World Health Organization (WHO) child growth standards median). One recent study suggests that during the 1920s, between 15% and 20% of British children were more than two standard deviations below the current WHO child growth standards. For comparison, the most recent estimates (1990-2001) range between 0.73% and 3.56% (Schneider et al,2026).

Together, these figures provide further indication of the extent to which children’s health has improved over the course of the last century.

They have been also accompanied by profound reductions in both the prevalence of life-threatening diseases, and infant and child mortality rates.

Towards the end of the 19^th century, the British government introduced arrangements for the notification of infectious diseases, a legal requirement to report suspected cases of certain diseases to the public health authorities. But some of the most common childhood infections only became notifiable much later and the notifications were not differentiated by age. Nevertheless, there have been substantial declines in the prevalence of these diseases within the population as a whole since the 1920s (see Figure 1).

Between 1926 and 2021, the notification rate for diphtheria fell from 1.31 per thousand to almost zero; that for scarlet fever, from 2.1 per thousand to less than 0.05 per thousand; for whooping cough, from 1.38 per thousand in 1940 to 0.009 in 2021; and for measles, from a peak of 16.53 in 1961 to 0.006.

Figure 1: Infectious disease notification rates in England and Wales, 1912-2021

Sources: Notifications: Notifiable diseases: historic annual totals – GOV.UK; Population: Estimates of the population for the UK, England, Wales, Scotland and Northern Ireland, Office for National Statistics (ONS).
Note: Figures for diphtheria for 1912-31 include membranous croup.

These declines also contributed to an overall improvement in infant and child survival rates. In 1926, deaths from diphtheria, measles, scarlet fever and whooping cough accounted for approximately 25% of all deaths between the ages of one and ten (Registrar-General, 1927, Table 17).

Further, between 1926 and 2024, the infant mortality rate for England and Wales declined from 70 deaths per thousand births to 3.9 (Mitchell, 1988; ONS, Table 1). The death rate among children aged one to 15 declined from 3.83 deaths per thousand living to 0.086 (Human Mortality Database; ONS).

What explains the changes in children’s physical health?

These figures bear witness to the extent of improvements in children’s physical health since 1926. But we also need to recognise the importance of earlier advances. Indeed, child mortality rates began to improve in England and Wales from the 1850s, and infant mortality started to fall after 1900 (Floud et al, 2011).

Recent estimates suggest that the prevalence of child stunting declined substantially during the first two decades of the 20^thcentury (Schneider et al, 2026). These figures imply that at least some of the improvements that occurred after 1926 originated earlier.

Over the last 40 years, economic and demographic historians have devoted considerable attention to understanding the reasons for these improvements in health – and especially mortality – during the second half of the 19^th century.

Although much of this work has focused on the reduction in mortality from infectious diseases, this is directly related to the decline in child mortality since the majority of these deaths occurred in childhood. Indeed, the decrease in infectious disease mortality accounted for approximately half of the overall fall in child mortality between 1851-60 and 1901-10 (Harris, 2008).

In 1976, the medical scientist Thomas McKeown identified a number of potential reasons for the decline in infectious disease mortality. These included a reduction in the virulence of certain infections, therapeutic intervention, better sanitation and improved nutrition (McKeown, 1976). Although he acknowledged that the fall in mortality from scarlet fever was probably attributable to a decline in virulence (see also Davenport, 2020), he thought that the most important factors were associated with nutrition and sanitation.

Subsequent generations of economic historians have worked hard to establish which of these factors were more important, but the results have not been entirely conclusive. One recent study reports that improvements in water supply were associated with declines in both infant and child mortality between circa 1845 and 1884, but the effects from 1885 onwards were much smaller (Aidt et al, 2023).

Although efforts to improve the sanitary environment continued after 1900, attention also started to shift towards what became known as personal health services.

In 1905, a medical officer, Leslie Mackenzie, asserted that ‘if any clear issue has yet emerged, it is that we are entering on an era of personal hygiene’, and that this had to begin with the child (Harris, 1995).

This understanding was reflected in the development of infant, maternity and child welfare services and the introduction of new arrangements for the medical inspection and treatment of school children (Harris, 2025).

But contemporaries also recognised that the impact of these services was hampered by the persistence of child poverty. During the 1920s and 1930s, various investigations demonstrated that children from disadvantaged backgrounds were shorter and lighter than wealthier children, and these disparities continued after the Second World War (see, for example, Spence, 1934; Floud and Harris, 1996).

Economic historians have explored different ways in which economic and demographic developments have contributed to changes in children’s health. Anthropometric historians have argued that average height reflects the net impact of changes in the quality and quantity of childhood nutrition and the demands that the external environment – and especially the disease environment – places on them.

Each of these factors can be closely related to family size. One recent study suggests that rising household income and reductions in average family size may have accounted for up to 40% of the increase in children’s heights between 1906 and 1938 (Hatton and Martin, 2010). These changes may have also helped to reduce the disease burden by limiting the extent of household overcrowding (Hatton, 2017).

Vaccination campaigns have also had a significant impact on the prevalence of childhood diseases. Although the incidence of many childhood infections was probably falling before 1940, the rate of decline accelerated thereafter.

Vaccination against diphtheria was introduced in 1942, and vaccines against tuberculosis, polio, whooping cough and tetanus were introduced during the 1950s. These innovations were followed by the introduction of vaccines against measles and rubella in 1968 and 1970 (UK Health Security Agency, 2025). The introduction of each of these vaccines was closely followed by substantial reductions in the prevalence of many childhood diseases (see Figure 2).

Figure 2: Notification rates in England and Wales for diphtheria, whooping cough, polio and measles

Sources: As for Figure 1.

What are the implications of the changes in children’s health?

As we have seen, children’s health is a powerful reflection of economic and social conditions more generally. In turn, better health outcomes among children also influence a range of other indicators.

Several studies suggest that changes in average height are associated with both cognitive development and economic productivity (see Harris, 2021). Others show that there is a close relationship between the heights of children and health in later life, although some of these relationships may also be changing.

For example, in 1984, a classic Norwegian study showed that height was inversely related to mortality, but this relationship varies between different diseases (Waaler, 1984).

More recent studies suggest that although height is inversely related to mortality from diseases such as cardiovascular disease, whose overall significance is declining, it may be positively related to deaths from diseases such as cancer, whose relative significance is increasing (Perkins et al, 2016; Office for Health Improvement and Disparities, 2025b).

Another study suggests that recent increases in the heights of children in deprived areas may be directly associated with increases in childhood obesity (Moscrop et al, 2026).

These findings suggest that even longstanding biological relationships may need to be reassessed in the light of changing historical circumstances, but they also highlight the importance of enduring health concerns.

There may be some debate as to whether the heights of the most recent cohorts of children are increasing or decreasing, but there is also growing concern about childhood obesity. Between 1995 and 2004, the percentage of English children who were defined as ‘obese’ increased from 12% to 19%, and the share has remained between 14% and 17% since 2008. These trends bring worrying implications for potentially life-threatening diseases, such as cancer and type-2 diabetes (NHS Digital, 2026; Wise, 2025).