One in five children in rich countries lives in relative poverty, according to a UNICEF report published today.

The report puts the United States and the UK among the world's worst performers for youth well-being.

It says nearly 20% of children in those countries lack access to sufficient safe and nutritious food.

The 'Innocenti Report Card' took into account factors such as education, mental health, alcohol abuse, economic opportunities and the environment to rank 41 high-income countries for overall youth well-being.

Germany and the Nordic countries topped the list while Romania, Bulgaria and Chile came in at the bottom, with New Zealand and the US in 34th and 37th place respectively.

The US had relatively low scores in terms of poverty, hunger, health, education and inequality.

New Zealand performed particularly badly in terms of adolescent mental health, with the highest suicide rate in the world for people aged 15 to 19 - almost three times the average for the countries surveyed.

The number of adolescents reporting mental health problems is increasing in the majority of the countries included in the study, along with the rate of obesity among young people.

Even in Japan and Finland, among the best performing countries in the list, around a fifth of 15-year-olds do not reach baseline educational standards, the report said as it called for greater focus on disadvantaged groups.

Ireland is among a group, which includes German, Poland and South Korea, where more than 75% of 15-year-olds attained the basic level across three subjects, which the report said shows their national educational approaches are more successful than others in ensuring baseline competency.

The report also looked at adult employment rates, where growing up in a household where no adult works has been linked to a greater risk of experiencing poverty and poorer child well-being in terms of learning and bullying.

Around one child in seven lives in a jobless household in Bulgarian, Hungary, New Zealand, Spain and the UK and the results overall ranged from 2% of children in Japan living in such a household to 19% in Ireland.