Child and Adolescent Obesity Dramatically Increased Since 1975

The number of overweight and obese children and adolescents worldwide has soared in the past 4 decades, a new study has shown.

The study, published in The Lancet, analyzed trends in body-mass index (BMI), underweight, overweight, and obesity in children aged 5 to 19 from 200 countries.

“Being underweight, overweight, or obese during childhood and adolescence is associated with adverse health consequences throughout the life course,” wrote the authors.

The number of children and adolescents with obesity has increased by more than 10-fold. In 2016, 50 million girls and 74 million boys suffered from obesity, up from 5 million and 6 million in 1975. Globally, the percentage of child and adolescent obesity rose from 0.7% to 5.6% for girls, and from 0.9% to 7.8% for boys.

Rates of obesity were highest (30%) in some Polynesian islands, followed by the United States (20% or higher), and several countries in the Middle East, North Africa, and the Caribbean.

Obesity in children and adolescents has been linked to higher risk and earlier onset of several chronic diseases, including type 2 diabetes, worse psychosocial and educational outcomes, and lifelong harms since weight loss is hard to accomplish.

“The trends show that without serious, concerted action to address obesity, from improving diets and providing the means by which to increase physical activity, to implementing the health system measures required to address overweight and obesity in young people early on, then the health of millions of people will be needlessly placed in great jeopardy, leading to immense human and economic costs to communities," Leanne Riley, a study author from the World Health Organization, said in a statement.

While there has been a dramatic increase in cases of obesity, there are still more underweight children and adolescents globally. In 2016, 75 million girls and 117 million boys were moderately or severely underweight. Two-thirds of these underweight children lived in South Asia, where 20.3% of girls and 28.6% of boys are underweight. Being underweight has been associated with higher risk of infectious disease, and adverse pregnancy outcomes for girls, including maternal mortality, delivery complications, preterm birth, and slow intrauterine growth.

Over the past 4 decades, the percentage of underweight children and adolescents decreased for both boys and girls, highlighting the higher rates of increase in obesity than the rates of decline in under-nutrition. If post-2000 trends continue, obesity is likely to surpass moderate and severe underweight by 2022.

The authors noted the need for policies to prevent childhood obesity and provide food security for low-income countries.

“While there have been some initiatives led by governments, communities, or schools to increase awareness about childhood and adolescent obesity, most high-income countries have been reluctant to use taxes and industry regulations to change eating and drinking behaviors to tackle childhood obesity,” Majid Ezzati, PhD, MA, MEng, a study author from Imperial College London, said in a statement. “Most importantly, very few policies and programs attempt to make healthy foods such as whole grains and fresh fruits and vegetables affordable to poor families.”

There should also be treatments such as behavioral therapy to change diet and exercise, screening and management of hypertension and liver problems, and in extreme cases, bariatric surgery, the authors said.