The study shows that the global number of obesity cases almost doubled since 1980. In 2014, 10 per cent of men and 14 per cent of women aged 18 years or older were obese. More than 42 million children under the age of five were overweight in 2013.
The proportion of adults with a body mass index (BMI) of 25 kilogrammes per square metre (kg/m2) or more increased to 36.9 per cent from 28.8 per cent for men, and to 38 per cent from 29.8 per cent for women in 1980-2013. To date, no country in the world has succeeded in reducing the obesity epidemic, says the study conducted by a team of researchers from New Zealand and the United States.
“Overweight and obesity have become major problems for public health worldwide,” Stefanie Vandevijvere, a researcher on global health and food policies at the University of Auckland in New Zealand who led the research team, tells SciDev.Net.
The researchers analysed the increase in the dietary energy supply and obesity in 69 countries (24 high-income, 27 middle-income, 18 low-income).
According to the FAO (the UN’s Food and Agriculture Organization), the dietary energy supply is the average amount of energy consumed in the form of food per capita and per day, measured in calories.
The researchers also compared the data relating to dietary energy supply with average adult weight and BMI in these 69 countries, based on the FAO and WHO databases in 1971-2010.
The study showed that obesity is increasing in several countries in correlation with the increase in dietary energy supply. In 45 countries (65 per cent), this was “more than enough to explain the parallel increase in weight”.
“Our study reveals that excess dietary energy supply is a likely cause of excess calorie intake and can easily explain the weight increase found in the majority of countries,” Vandevijvere says.
The increase in dietary energy supply over the decades is “largely due to ultra-processed food products, which are very appetising, relatively cheap and widely advertised, and significantly facilitate excess calorie intake”.
The study pointed out health problems resulting from obesity such as diabetes, high blood pressure, coronary heart disease, stroke and certain types of cancer.
While recognising that other factors such as lack of physical activity can lead to weight gain, the study recommended that countries put policies in place to offer healthier food products.
“These policies include restricting the marketing of unhealthy food products to children, having additional nutrition labelling on packaging, having pricing strategies for food products, and improving the quality of food sold in schools and other public places,” Vandevijvere notes.
Francesco Branca, director of the WHO’s nutrition department for health and development, adds: “It is essential that countries question the way in which they are running their food system.”
He says this will require different sectors getting involved, mainly those in agriculture, food production, health, social protection and education.
The study concluded that “we must also examine the way in which trade and investment agreements and agricultural policies affect domestic food environments, food habits of individuals and disease patterns in countries”.
>Link to full paper in Bulletin of the World Health Organization
This article has been produced by SciDev.Net's South-East Asia & Pacific desk.