Our kids’ mental wellbeing is among the worst of all developed nations.

Only two other countries fare worse for children’s “life satisfaction”, according to Unicef analysis of child health data.

And 31% of UK five-to-19-year-olds are overweight or obese, making Britain 28th out of 41 countries providing the data.

Unicef warned child wellbeing could worsen as a result of the pandemic.

Sacha Deshmukh, chief executive of Unicef UK, said: “The Government can and should take action now to avert a looming and long-term crisis for children.”

British youngsters ranked in the bottom three of 33 wealthy nations surveyed for “life satisfaction”.

Children were surveyed at 15 and asked to rate how satisfied they felt with their lives on a scale from 0 to 10.

Unicef UK Chief Executive Sacha Deshmukh

Some 36% of those in the UK rated their mental wellbeing as poor, scoring below five. Only Japan and Turkey fared worse.

The causes of such poor mental wellbeing are disputed, but factors include family life, healthcare, schooling and poverty.

The Netherlands performed best for mental wellbeing, followed by Mexico, Romania, Finland, Croatia, then Switzerland.

The report said: “This is more than merely a question of momentary ‘happiness’.

“Compared with children with average to high life satisfaction, those with low life satisfaction were about eight times as likely to report family conflict, six times as likely to feel that they could not express their opinions, five times as likely to be bullied, and more than twice as likely not to look forward to going to school.”

The UK ranked 27th among 41 countries on overall child wellbeing.

The Netherlands was top of the list, followed by Denmark, Norway, Switzerland, Finland and Spain.

France was seventh, the Republic of Ireland 12th and Germany 14th.

At the bottom was Chile, followed by Bulgaria and then the US. Japan fared best on obesity followed by Estonia, Lithuania and Latvia.

The US was the worst in this category, with New Zealand the second worst-performing country and the UK only a few places ahead at 28.

The report said: “Obesity is a serious problem for both medical and psychological reasons.

“It contributes to diabetes, cardiovascular diseases, hypertension, cancer, gallbladder disease and a shorter life expectancy. It takes a social and emotional toll by limiting participation in social life and lowering self-esteem.”

The UK ranked 19th for physical health and 26th for skills.

Unicef UK boss Mr Deshmukh said: “As the UK emerges from the worst of the pandemic the Government must develop and deliver a comprehensive cross-departmental children’s recovery plan to ensure no child is denied their right to health, safety, education and happiness.

“Sadly, it seems that poor mental health, obesity and inadequate social and academic skills are now the hallmarks of modern childhood.”

As pupils return to school after up to six months off amid lockdown, he added: “Lockdown measures, school closures and the wider impacts of the coronavirus pandemic have now added layers of complexity to the challenges facing children in the UK.

“For many children, life is now even tougher and a bright, fulfilling future is further from reach.”

The countries included in the analysis are all considered High-Income Countries by the United Nations children’s fund.