The private sector “must be held accountable for the health impacts of their products”, warned the head of the World Health Organization (WHO) amid news that obesity has quadrupled in children and more than doubled in adults since 1990.

Dr Tedros Adhanom Ghebreyesus was speaking ahead of the release of a huge global obesity study involving over 220 million people from more than 190 countries published in The Lancet on Friday. 

“Getting back on track to meet the global targets for curbing obesity will take the work of governments and communities, supported by evidence-based policies from WHO and national public health agencies,” added Tedros.

Tonga, American Samoa and Nauru have the world’s highest obesity rates, affecting some 60% of their adult populations. 

“The largest increases are in some countries in the Pacific, the Caribbean, the Middle East and North Africa, and some of the newly high income countries like Chile,” said senior author Professor Majid Ezzati, of Imperial College in London, at a media briefing on Thursday.

The US is the only high-income country that features in the ten worst affected countries – with the 10th highest obesity rate in men. Some 43.8% of US women and 41.6% of men were living with obesity in 2022.

Meanwhile, obesity is slowing in a handful of west European countries – notably Spain and France. However, countries with the lowest obesity rates are generally low-income countries with high rates of under-nutrition, with a few exceptions such as Japan and Viet Nam.

Huge rise in child obesity

In 1990, around 31 million children (2,1% of boys and 1.7% of girls) were obese. But 32 years later, there had been a fourfold increase in both boys (to 9,3%) and girls (6.9%) affecting almost 160 million children.

“It is very concerning that the epidemic of obesity that was evident amongst adults in much of the world in 1990 is now mirrored in school-aged children and adolescents,” said Ezzati.

While boys are more likely to be obese than girls globally, this trend is reversed in adulthood with many more women than men living with obesity. 

But men seem to be catching up. Obesity in men has nearly tripled over the past 32 years, while it has doubled in women. 

“Different forms of malnutrition still coexist in many countries,” said Dr Francesco Branca, WHO Director of Nutrition and Food Safety and one of the co-authors of the study. 

“The child who was undernourished in the first years of life can later become overweight or obese as an adolescent or an adult. Undernutrition and obesity are two faces of the same problem, which is the lack of access to healthy diets.”

Greater risk of NCDs

Undernourished people are more susceptible to infectious diseases, while obesity can lead to Type 2 diabetes, heart disease, certain cancers and affect bone health and reproduction, added Branca, who was also addressing the briefing.

“The increase in the double burden of malnutrition is a result of a transition in food system and lifestyle that has not been governed by public health policies,” he added.

However, despite WHO guidelines on what countries can do to address the massive rise in consumption of energy-dense ultra-processed food, adoption by member states has been slow.

At the World Health Assembly in 2022, member states adopted the WHO Acceleration plan to stop obesity. Core interventions include promoting breastfeeding,  regulating marketing of ultra-processed food and drinks to kids, taxation and warning labels on foods high in fats, salt and sugar.

“The reason why the epidemic has progressed so quickly is because the policy action has not been incisive enough,” said Branca, adding that countries had focused on behaviour change rather than “structural elements, which is the policies around food environment”. 

However, he added that more countries were taxing sugary drinks, although “not many countries have done it for sufficiently long time and in ways that are demonstrated to be most effective”. 

“Very few countries put a restriction on marketing food to children. We know that some South American countries are taking that action much more effectively, and we look forward seeing the impact of those policies,[as well as] having warning signs on the processed food which would really discourage people from f buying products which are high in salt, sugar and fat”.

If these policies were implemented, this would likely lead to food and beverage companies reformulating their products to reduce harmful ingredients, he added.

Role of new weight-loss pills?

Branca said that the WHO was currently looking at the efficacy of the new drugs called glucagon-like peptide 1 (GLP-1) agonists – such as Wegovy, Ozempic – which have been approved as weight-loss medication in some countries.

“The solution is still is a transformation of the food system and in the environment such obesity can be prevented,” Branca stressed.

However, the GLP-1 drugs could provide a tool to help those that already live with obesity, as long as they were integrated into a primary healthcare package to manage obesity that included guidance on exercise and diet.

The new study was conducted by the NCD Risk Factor Collaboration (NCD-RisC), in collaboration with the World Health Organization (WHO), and involved over 1,500 researchers. They based their analysis on body mass index (BMI). Adults with BMI 30kg/m2 and over were classified as obese and underweight if their BMI was below 18.5kg/m2. For children, BMI was adjusted according to age. .

Image Credits: World Obesity Federation.