New Zealand has the highest death rate for teenagers and young people among 19 of the world's developed, wealthy countries.
It also ranks poorly in terms of adolescent suicide, pregnancies and deaths related to cancer and respiratory illness.
The international comparisons were made by British healthcare think tank Nuffield Trust, which looked at the UK's record on adolescent health and wellbeing in relation to 18 countries of similar economic and cultural backgrounds.
New Zealand had by far the highest mortality rate for people aged 10 to 24 years - around 35 deaths per 100,000 people.
This was driven by its relatively high youth suicide rate and youth road toll. In these areas, New Zealand ranked near or at the bottom of the rankings at nearly every level - early teens, late teens and over-20s.
Only the United States ranked worse than New Zealand on obesity rates and teen pregnancy rates. And this country placed 18th out of 19 when it came to asthma-related deaths - which were often the result of substandard housing.
"It is quite distressing on the health front," said Associate Professor Joe Boden, who works on the 30-year-old Christchurch Health and Development Study.
The study's broad definition of adolescence - 10 to 24 years - is based on scientific evidence that humans' brains are not fully mature until at least 24.
"This is where you are developing life habits, essentially," said Boden. "Diet, exercise - these things get established during this period.
"So it's really important that you're able to find ways to help kids through this in a healthy manner. And comparing ourselves internationally, we're not doing very well."
The British study creates a different picture of adolescence in New Zealand to various longitudinal studies, which broadly show that young people are thriving.
"The majority of kids do have some problems here and there, but they generally grow up pretty healthy and happy and they're well-educated," said Boden.
"So it doesn't shake my belief that New Zealand is a good place to grow up. But in terms of rare events or severe outcomes, we're not doing particularly well in those areas as you can see from general mortality, years of life lost, and smoking and obesity."
New Zealand fared better in some areas, in particular the number of youth not in employment or training (NEET), and diabetes rates, where it placed in the middle of the pack.
Out of all the indicators in the report, suicide was possibly the most concerning. While most indicators were trending downwards, the youth suicide rate in New Zealand had been steady for 12 years.
The Government hopes to address this through its Mental Health Inquiry, which is specifically looking at the existing work on suicide prevention.
Cancer survivor Jake Bailey, 21, said the relatively high rates of cancer deaths in the study were disappointing. But during his treatment he had witnessed changes which gave him hope, including plans for a separate, specialised adolescent cancer ward in Christchurch Hospital.
Bailey, a public speaker and Herald columnist, also said many of the negative indicators in the study could be traced back to mental health. He believed that a sea change was occurring in this area in New Zealand.
"I genuinely believe that my generation will be the one which changes the discussion around mental health in New Zealand."
A separate study, released today by the Children's Commissioner and Oranga Tamariki, found that most New Zealand children and young people said they were faring well.
The study of 6000 children also found that a third said they were facing challenges in some aspects of their life, and one in 10 faced multiple challenges, including racism, discrimination, bullying, poverty, violence and drugs.
Adolescent Health and Wellbeing - how NZ fared
• Mortality rate, 10-19 year-olds: 19th out of 19 countries
• Birth rate, 15-19 year-olds: 18th
• Not in education or training, 15-19 year-olds: 8th
• Asthma mortality rate, 10-24 year-olds: 18th
• Obesity rate, 15-19 year-olds: 18th
• Diabetes rate, 10-24 year-olds: 11th
• Cancer mortality rate, 10-to-24 year-olds: 7th
• Suicide rate, 10-24 year-olds: 17th
• Suicide rate, 10-14 year-olds: 19th
• Suicide rate, 15-19 year-olds: 19th
• Road crash deaths, 10-24 year-olds: 17th
The countries: United Kingdom, Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Greece, Ireland, Italy, Japan, the Netherlands, New Zealand, Portugal, Spain, Sweden, United States.
(International comparisons of health and wellbeing in adolescence and early childhood, Nuffield Trust)