Childhood obesity: a leading health economist discusses latest research

To mark World Obesity Day 2022, Professor Franco Sassi of the Business School, reflects on a new report on childhood obesity.

Professor Sassi and his team contributed to the latest report from the STOP Project, which shows that rates of obesity are increasing fastest in countries with low levels of income. According to the research, the estimated rates of overweight and obesity in children aged 5–19 are of up to 65% in the Pacific islands, 39% in the United States, and up to 31% in European countries. 

The research is published in a report in Obesity Reviews which outlines the factors that lead to childhood obesity, including prenatal exposures, dietary patterns, the impact of sedentary behaviour and the role of epigenetics.

Professor Sassi, Director of the Centre for Health Economics & Policy Innovation, discusses the findings of the report and what this means for policymakers.

Can you tell me a bit more about this latest report?

This paper is a result of collaborations involving a large multidisciplinary group of researchers across Europe and in Latin America. It brings together ten papers exploring the different factors that contribute to childhood obesity, from ultra-processed foods and other dietary patterns, through to physical activity and the impact of built environment and traffic-related and air pollutants.

We also investigate obesity risk factors in early life and the genetic and metabolic determinants of obesity. This latest report, which is one of 10 papers, helps to build a picture of the vast range of factors which can contribute to the development of obesity in children.

What’s clear is there is no one driver that leads to childhood obesity and that the situation is more complex than being simply about energy balance.

Why are the findings so important?

Childhood obesity is increasing rapidly, particularly in countries at low levels of income. Obesity is still poorly understood, and often simplistically viewed as a matter of individual responsibility. However, we know there are a wide range of factors, over which individuals have limited or no control, that influence a person’s risk of developing obesity.

"Obesity is very complex and we need to gather as many pieces of the jigsaw as we can if we want to design effective actions and successfully address childhood obesity." Professor Franco Sassi Director of the Centre for Health Economics & Policy Innovation

This latest report provides new evidence that improves our understanding of the wider drivers of obesity. We highlight, among others, the indirect consequences of air pollution on physical activity and health; the detrimental impact of diets that include large amounts of highly industrially processed, and heavily promoted, foods; and the importance of a healthy start in life. Our findings convey a strong message that obesity is very complex and we need to gather as many pieces of the jigsaw as we can if we want to design effective actions and successfully address childhood obesity.

What is the main takeaway message for policymakers?

To support people, including children, to adapt their behaviour we must change the environment in which they live and in which they make their choices on a daily basis.  We must turn the incentives that have fuelled obesity into incentives for people to make healthy choices that are not conducive to obesity. Understanding the wider factors that lead to obesity, and the way these impact on people in different circumstances, is important for targeting policies towards protecting the most vulnerable.

What’s next in this research area?

The latest report highlighted several promising areas for further research. In these, we may soon be able to find more signs of how and why obesity develops. We need this evidence to formulate actions that have the potential to turn the tide of the childhood obesity epidemic, especially among the most vulnerable children and families.

The most promising leads our research has produced so far have to do with the conditions experienced before birth and in the early years of life. Preventing obesity in early childhood by removing, or mitigating, those risks will increase the chances of a healthy weight in adolescence, when the impacts of obesity on children’s current and future life become more important.

The paper, ‘Position guidelines and evidence base concerning determinants of childhood obesity with a European perspective’ is published in Obesity Reviews.