A major new study tracking Body Mass Index (BMI) trends globally has found Kiwi kids and teenagers are among the unhealthiest in the world.
Over 35 years, researchers analysed data from 2000 population-based studies with the height and weight measurements of 65 million children and adolescents across 200 countries.
The study, which has just been published in journal The Lancet, looked at physical growth trends and found "wide variations in height and BMI" among school-aged children and "faltering growth" in many countries.
This was "most likely due to [a] lack of adequate and health nutrition during school years," a media release says.
These unhealthy growth trends, meaning too little height gain and/or excess weight gain, were detected in several countries, including New Zealand, the United States, Malaysia, Mexico and sub-Saharan Africa.
"Unhealthiest changes - gaining too little height, or too much weight for their height compared with children in other countries, or both of these - occurred in many countries, including for boys and girls in New Zealand, and for boys in some Pacific Island nations."
The study found that in 2019, 19-year-olds with the largest average BMI lived in the Pacific Islands, the Middle East, the US, and New Zealand. It was the lowest in countries in south Asia and east and central Africa.
A key finding is that in some countries, children grow healthily until the age of five, but do not continue to during their school years.
The study's authors are therefore calling for better nutritional programmes to be taught to students.
"Our findings should motivate policies and interventions at home, at school, in the community, and through the health system to support healthy growth during the entire period from birth to adolescence through enhanced nutritional quality, healthier living environment, and provision of high-quality preventive and curative care," the study says.
One of the New Zealand authors, Professor Jim Mann - director of Healthier Lives National Science Challenge and the Edgar Obesity and Diabetes Research Centre - has called obesity a "silent killer" pandemic.
He believes this study shows the issue is getting worse in New Zealand and wants to see a national nutrition survey carried out here.
"New Zealand has not had a survey since 2002 so we don’t actually know what New Zealanders are consuming," he said.
"We have also called for school-based healthy food and drink policies and this study reinforces the need for such policies as well as restrictions on advertising unhealthy foods to children."