The number of young South Africans suffering from obesity doubled in six years while this took 13 years to happen in the United States.

This is according to research published in the International Journal of Epidemiology on December 14 last year.

Local researchers from the University of KwaZulu-Natal (UKZN)‚ University of the Witwatersrand (Wits)‚ and international researchers from Denmark and England analysed the body mass index (BMI) of South African children‚ adolescents and young adults from 2008 to 2015.

Your BMI is calculated by dividing your weight by your height and then dividing the answer by your height again.

The study analysed the mean BMI of 28‚247 people from 7‚301 households by age and year. The analysis did not include children under the age of five years.

Researchers found there was a greater increase of obesity in low- and middle-income countries (LMIC) compared to global trends.

“South Africa is undergoing rapid socioeconomic and demographic changes that have triggered a rapid nutrition transition.”

There was also a rapid rise in the BMI of people between the ages of six and 25 years‚ especially among women in urban areas of middle-high socioeconomic groups. The largest gains were in KwaZulu-Natal‚ Free State‚ North West and Limpopo.

This can be attributed to growth in gross domestic product (GDP)‚ more disposable income‚ increased exposure to globalisation and the establishment of large urban informal settlements. This has driven changes in dietary patterns to cheap energy-dense foodstuffs‚ people drinking more sugary drinks and increased consumption of saturated fats and animal proteins.

Researchers said if lower- and middle-income countries continue to expand faster than the global pattern it affects the development of the country and overtaxes the national health care budget. The indirect costs will be a burden on households due to lost wages.

“Overweight/obesity is also likely to reduce the productive life of working individuals and negatively impact on local GDP through absenteeism.”

According to the researchers there is a 70% chance of an overweight child remaining overweight as an adult.

The risk of childhood obesity includes diabetes‚ hypertension‚ cardiovascular and kidney diseases.

The researchers recommended the introduction of more sugar tax‚ clearer food labelling‚ revising school feeding programmes and banning unhealthy food marketing to children .