The UK has been accused of failing its children, as it comes bottom of a league table for child well-being across 21 industrialised countries.
Unicef looked at 40 indicators from the years 2000-2003 including poverty, family relationships, and health.
Unicef - the United Nations children's organisation - says Child Poverty in Perspective: An Overview of Child Well-being in Rich Countries is the first study of childhood across the world's industrialised nations.
In its league table the Netherlands came top, followed by Sweden, Denmark and Finland.
Unicef UK executive director David Bull said all the countries had weaknesses that needed to be addressed. "By comparing the performance of countries we see what is possible with a commitment to supporting every child to fulfil his or her full potential," he said.
The authors say they used the most up-to-date information to assess "whether children feel loved, cherished, special and supported, within the family and community, and whether the family and community are being supported in this task by public policy and resources".
But they added: "The process of international comparison can never be freed from questions of translation, culture, and custom."
Professor Jonathan Bradshaw, from York University, one of the report's authors, put the UK's poor ratings down to long term under-investment and a "dog-eat-dog" society. "In a society which is very unequal, with high levels of poverty, it leads on to what children think about themselves and their lives. That's really what's at the heart of this," he said.
The UK government said its initiatives in areas such as poverty, pregnancy rates, teenage smoking, drinking and risky sexual behaviour had helped improve children's welfare.
Welfare reform minister Jim Murphy said the Unicef study was important, although it used some data which was now out of date. "Hopefully it leads to a wider conversation about what more we can do to eradicate poverty," he said.
The Children's Commissioner for England, Professor Sir Al Aynsley-Green, said: "We are turning out a generation of young people who are unhappy, unhealthy, engaging in risky behaviour, who have poor relationships with their family and their peers, who have low expectations and don't feel safe."