Ofsted conducted more than 900 visits to education and social care providers in September and October, and the results revealed that some children were struggling to cope with the loss of full-time in-class education.
"We were told of older children losing stamina when it came to reading and writing; some who had lost physical fitness; and others showing signs of mental distress, including an increase in eating disorders and self-harm," Amanda Spielman, the UK's chief inspector of education, said in a commentary that accompanied the report.
In some cases, Ofsted inspectors found that young children, whose parents had difficulty in gaining time off work to provide full-time care, had lost their ability to conduct tasks such as eating with a knife and fork.
As the first wave of the COVID-19 pandemic hit this past spring, many schools in the United Kingdom moved to remote learning, although the children of essential frontline workers were permitted to receive in-class teaching.
On Monday, the UK Department of Health and Social Care registered 21,350 new cases of COVID-19, taking the country's case total above 1.2 million.