There are now 10 times as many obese children and teens around the world than there were 40 years ago, and if current trends continue, there will soon be even more kids dangerously overweight than underweight, according to a new World Health Organization study.

The study, published ahead of World Obesity Day, found that the rates of childhood obesity soared from less than 1 per cent in 1975, to nearly 6 per cent in girls and nearly 8 per cent in boys in 2016.

Put another way, there were only 11 million obese kids and teens around the world in 1975. By 2016, that number had risen to 124 million, with several million more children considered overweight but below the threshold for obesity.

Kids and teens in many countries in East Asia, Latin America and the Caribbean have rapidly moved from being mostly underweight 40 years ago to being mostly overweight.

Current rates of childhood obesity are highest among many Polynesian islands, the U.S., and many countries in the Middle East, including Egypt, Kuwait, Qatar and Saudi Arabia.

In 2016, the childhood obesity rate was highest in Polynesia and Micronesia, where a staggering 25.4 per cent of girls and 22.4 per cent of in boys are not just overweight but obese.

Among high-income countries, the United States had the highest obesity rates, where girls ranked 15th and boys ranked 12th worldwide.

Canada was ranked 44th for obesity among boys and 67th for girls. Overall, 9.9 per cent of Canadian girls are obese, as are 14.7 per cent of boys.

The full results appear in The Lancet journal.

There are still more underweight than overweight kids in the world. But if the current trends continue, that will reverse by 2022.

The study’s lead author, Prof. Majid Ezzati of Imperial College London’s School of Public Health, says obesity rates continue to soar in low- and middle-income countries, in part because of the growing availability of high-calorie, low-nutrient processed foods. And while obesity rates have mostly plateaued in higher income countries, they remain “unacceptably” high.

“We are looking at a generation of children who are gaining weight in their… childhood and will live with the effects over their lifetime of obesity,” he told CTV News.

Ezzati said the “worrying trend” of rising obesity rates reflects the impact of food marketing and policies around the world, noting that unhealthy foods are aggressively marketed to children throughout the world.

“At the same time, healthier options, fresh foods, are priced out of reach of the poorest people round the world,” he said.

He said what’s needed are regulations and taxes to protect children from unhealthy foods, as well as ways to make healthy, nutritious food more available at home and school.

Dr. Katherine Morrison, a pediatric endocrinologist and associate professor at the department of pediatrics at McMaster University in Hamilton, Ont., said obese children and teens are “much more likely” to develop heart disease and other health problems like diabetes in middle age.

“The health consequences certainly are apparent in adulthood,” she told CTV News.

“We do see it on a day-to-day basis and it makes me worry to see where these kids are heading,” she said. “Our job is to find the tools to help them lead healthier lives.”

Dr. Nathalie Farpour-Lambert, the president-elect of the European Association for the Study of Obesity, said in a statement that obesity in childhood has a tendency to continue into adulthood, so that most who are obese as children will be obese into adulthood.

That’s why the group wants to see health-care professionals trained to prevent and treat childhood obesity.

The WHO has published an Ending Childhood Obesity (ECHO) Implementation Plan, which it says gives countries clear guidance on effective actions to curb childhood obesity.

It says that no single intervention can halt the advance of the obesity epidemic, but their plan outlines ways to encourage countries to reduce consumption of cheap, processed, calorie-dense, nutrient-poor foods.

It also offers advice on reducing the time children spend on sedentary activities and promoting more physical activity through recreation and sports.

“Overweight and obesity cannot be solved through individual action alone,” say the authors of the ECHO Plan.

“Comprehensive responses are needed to create healthy environments that can support individuals in making healthy choices grounded on knowledge and skills related to health and nutrition.”

With files from CTV’s medical specialist Avis Favaro and producer Elizabeth St. Philip