Today we publish an evidence review of the impact of pandemic life on physical development in the early years, which found that the pandemic has had a significant impact on key factors known to impact on physical development in children aged 0–5. The evidence in our review points to:

• decreases in physical activity and increases in sedentary behaviour such as screen time
• substantial increases in food insecurity along with increases in unhealthy choices in everyday meals and snacking, with reported rises in obesity
• challenges to being supported to breastfeed, particularly for women with other disadvantages
• decreases in oral healthcare use and reduced vaccination rates, along with decreases in sleep quality.

The review suggests a greater impact on children already vulnerable to poor physical health outcomes, namely children from low-income families, and those from UK minority ethnic families.

However, we found relatively little evidence that specifically examined the consequences of the pandemic on these factors for children aged 0–5 years in the UK, with much of it focused on older children, or conducted outside of the UK where responses to Covid-19 will have been different.

More evidence is therefore urgently needed to understand key factors known to impact on the early physical development of children in the UK. This includes young children’s physical health and growth and is not only important for their physical maturation and later physical health outcomes, but is also critical for development across all other psychological and cognitive domains.

It is encouraging that data for some factors highlighted in the report (which evidence shows are critical to early physical development) is being collected nationally and reported on via public health profiles. But recent publications released after we conducted our review show a worrying trend. For example, negative changes to diet, physical activity and food security, particularly for vulnerable families; as well as increases in obesity rates from 9.9% in 2019/20 to 14.4% in 2020/21 for 4 and 5 year olds. However, most of this data is not collected on children under 5 and cannot track children longitudinally to look at long-term impacts. In addition, these data collections, and all the evidence we reviewed, considered each factor influencing physical development individually. But we know that these factors are not discrete, and they interact bidirectionally and on other factors (for example obesity) to influence physical development as children grow.

Future research should examine these factors together and take account of the many wider risk and protective factors that impact on early child development, ranging from financial insecurity and parental mental health to early childhood services and stable family relationships.

Longitudinal cohort studies, such as the new Children of the 2020s Study and proposed Early Life Cohort Study, could provide a rich source of data for children born after lockdown in April, May, and June 2021 but need to ensure key physical development factors are comprehensively measured. However, these studies do not focus on young children who experienced the pandemic. Utilisation of current research studies to understand the impact of the pandemic, such as the Study of Early Education and Development (SEED) – but with a focus on physical development – should be an avenue for future research.

Along with more research, we also need to concentrate on mitigating the impacts in ways that we know work. It is encouraging to see the announcement of funding for additional support for families with young children, particularly for support for breastfeeding and maternal mental health. But we also need to understand what works to support other key factors highlighted in our review, such as physical activity, diet and nutrition, food security, oral health, vaccinations and sleep. A key way to do this is through the trialling and then scale-up of evidence-based interventions as with the Government’s rollout of the Nuffield Early Language Intervention. Evidence-based interventions to support physical development in the early years could have a substantial impact, particularly if they are targeted at children most at risk of poor outcomes.

Without prioritisation of more research aimed at understanding what works to support early physical development (such as encouraging physical activity, ensuring food security, and promoting good quality nutrition, breastfeeding, oral health, vaccinations and sleep) the impacts of the pandemic are likely to hinder many children’s early physical development. This will not only lead to increased health risks in childhood and later in life, but also to further physical development disparities for a whole generation of children who grew up in the pandemic.