Geneva (AFP)

Four in five teens in the world do not move enough, especially girls, according to a study released Friday by WHO, which recommends one hour of physical activity per day to improve health and prevent disease.

To estimate how many people aged 11 to 17 do not comply with this recommendation, the World Health Organization (WHO) for the first time analyzed data collected in 146 countries between 2001 and 2016 from 1.6 million students.

Globally, 81% of school adolescents - 85% of girls and 78% of boys - did not comply with the WHO recommendation in 2016, compared to 82.5% in 2001.

There is no suggestion that this trend has recently been reversed, said Leanne Riley, co-author of the study, during the media presentation of the study in The Lancet Child & Adolescent Health.

One of the reasons for the lack of youth activity is the "electronic revolution" that has changed the behavior of young people, the screens pushing them "to be less active," said Ms. Riley.

She also highlighted the growing insecurity that makes it difficult for adolescents, for example, to go to school on foot or by bike.

Young people are also more and more interested in studying, noted the study's principal author, Regina Guthold, who encourages teachers to encourage the daily movement of students "in a fun way".

- More active boys -

The percentage of adolescents not following the WHO recommendation ranges from 66% in Bangladesh to 94% in South Korea.

Among the other countries where lack of physical activity is the least common are also India, because of the place of choice given to cricket, and the United States, because of the good quality of physical education in schools, the high media coverage enjoyed by the sport and the good accessibility of the clubs.

Overall, the number of boys who did not have enough physical activity fell slightly between 2001 and 2016, from 80% to 78%, but there was no change for girls, the figure remaining close to 85% .

In most countries, the gap between boys and girls has even widened.

For "cultural reasons", girls are often less likely to practice sports or physical activity such as cycling to school, Guthold observed.

The largest gender differences were observed in Ireland and the United States. The latter "have gone to great lengths to promote mass sports participation, but these are events that are more likely to be of interest to boys," said Riley.

There are only four countries in the world where school girls are more active than boys: Tonga, Samoa, Zambia and Afghanistan.

The WHO study also shows "no obvious link" between the country income group and the insufficient physical activity of school-going adolescents, with inactivity rates high in all country categories.

The region where young people are most inactive is Asia Pacific, for both boys and girls. The lowest prevalence was found in rich countries for boys and in South Asia for girls.

According to the WHO, adolescents should accumulate at least 60 minutes a day of moderate-to-sustained physical activity.

In the face of the sedentarisation of societies, the countries set themselves the objective of reducing by 15% the physical inactivity of adults and adolescents, between 2018 and 2030.

"We have set ambitious goals but we are not meeting them and we need to do more if we are to stop the progression of obesity in this age group and promote better levels of physical activity," said Riley. .

© 2019 AFP