TUESDAY, Oct. 10, 2017 (HealthDay News) -- Childhood obesity has increased more than 10-fold worldwide since 1975, a new study reports.
But even more children are underweight than severely overweight, according to the analysis of data from 200 countries.
Researchers found that by 2016 overall obesity rates had jumped from less than 1 percent to almost 6 percent for girls and nearly 8 percent for boys -- with rates at 20 percent or higher in the United States, Egypt and some Polynesian islands.
A two-pronged strategy is needed to improve nutrition and reduce excessive weight gain, according to the study.
It was published Oct. 10 in The Lancet journal.
"Rates of child and adolescent obesity have increased significantly over the past four decades in most countries in the world," study author James Bentham said in a journal news release.
"While average BMI among children and adolescents has recently plateaued in Europe and North America, this is not an excuse for complacency as more than 1 in 5 young people in the U.S.A. and 1 in 10 in the U.K. are obese," said Bentham, of the University of Kent in England. Body mass index, or BMI, is a measurement of body fat based on height and weight.
Bentham said rates of child and adolescent obesity are accelerating in East, South and Southeast Asia, and continue to increase in other low- and middle-income regions.
Overall, 50 million girls and 74 million boys are now obese, which sets them up for serious health problems, the researchers said.
Obesity rates were highest (above 30 percent) in some islands in Polynesia, including Nauru and the Cook Islands. Besides the United States and some countries in the Middle East and North Africa, obesity rates of about 20 percent or more were seen in the Caribbean (Bermuda and Puerto Rico).
The United States, however, had moved from sixth place to 15th over the four-decade study. Puerto Rico, meanwhile, had climbed up the scale, from 29th to 17th.
In addition to the 124 million children considered obese, 213 million youths ages 5 to 19 were overweight around the world in 2016, the researchers said.
"The trends show that without serious, concerted action to address obesity ... the health of millions of people will be needlessly placed in great jeopardy, leading to immense human and economic costs to communities," said study author Leanne Riley, of the World Health Organization (WHO).
But despite the burgeoning obese population, being underweight remains a huge concern in many areas. The study found that 75 million girls and 117 million boys were moderately or severely underweight. Nearly two-thirds of these youngsters were in South Asia.
"There is a continued need for policies that enhance food security in low-income countries and households, especially in South Asia," said study author Majid Ezzati of Imperial College London.
Ezzati said the transition from underweight to overweight and obesity can happen quickly, referring to an influx of nutrient-poor, high-calorie foods in developing nations.
The findings highlight the "disconnect" between the global dialogue on overweight and obesity and initiatives focusing on under-nutrition, Ezzati said.
The research was led by the WHO and Imperial College London. The investigators relied on information from more than 2,400 prior studies.
The American Academy of Pediatrics has more on childhood obesity.