Imperial College London

Key actions needed to tackle obesity in cities outlined in new report


Person staring at burgers

Cities must develop comprehensive strategies to address the obesity epidemic which threatens to reverse 200 years of health gains, warns a new report.

A review of almost 100 research studies into city-wide approaches to address obesity finds that single measures are ineffective and multi-component initiatives spanning education, policy, regulation and the environment are urgently needed to reduce growing rates of obesity. To have the best chance at bringing lasting change interventions must also work across the individual, community and city level, the authors conclude.

"Using our recommendations, cities can make genuine and sustained improvements in obesity." Shaun Danielli IGHI

Led by Imperial College London’s Institute of Global Health Innovation, the report sets out a number of recommendations across five key areas that cities can take to mitigate this global issue. These include eliminating child poverty, making healthy choices easier, and the creation of healthy schools and childcare settings.

Shaun Danielli, study author and Research Fellow at the Institute of Global Health Innovation, said: “Obesity, in particular childhood obesity, risks undoing the increases in life expectancy that have been made over the past two centuries, and with poorer people and ethnic minorities bearing the brunt of the disease it is also widening existing inequalities.

“This is a social injustice, particularly given that obesity is proven to be amenable to policy measures. Using the recommendations laid out in our report, cities can make genuine and sustained improvements in obesity which will positively impact the lives of vast numbers of citizens.”

The global obesity crisis

Obesity is a largely preventable disease that brings with it an array of short- and long-term consequences for individuals, health systems and societies.

Children who are overweight do less well at school, are up to three times more likely to be bullied, and five times more likely to have obesity as an adult and therefore have a higher risk of the health issues linked with the disease, including high blood pressure and type 2 diabetes.

With more than half of the world’s population living in cities and urban living linked with a higher risk of obesity, the team carried out a major review of existing research to understand which approaches have been successful in reducing obesity in cities.

Published in The Lancet: EClinicalMedicine, the researchers examined 96 studies published between 1997 and 2019, carried out in 36 cities across five continents.

Cities have implemented a range of interventions, from restrictions on junk food advertising to education programmes and efforts to boost physical activity. For example Mexico City installed motion sensors in subway stations and if commuters complete 10 squats they gained a free transport ticket. Baltimore took a multi-level, multi-component approach to increase the availability and demand for healthier food, targeting low-income African American youth and their families.

Addressing systemic issues

Although strategies were met with varying degrees of success – with New York’s attempt to limit the size of sugary drinks in restaurants being overturned the day before it was due to roll out – those that were found to be most effective had backing from senior political leadership, who can influence, inspire and leverage change.

Successful initiatives were also those that were comprehensive, targeting multiple systems in a cohesive approach rather than offering a single, tokenistic intervention which does not address systemic and intertwined issues, such as poverty and nutrition. Philadelphia’s ‘Get Healthy Philly’ initiative, for example, set out to improve the city's nutrition, physical activity, and tobacco environments by making healthy choices easier for all citizens, achieving more than 6% reduction in childhood obesity rates.

A cohesive approach

"Everyone has a part to play in ensuring that these initiatives are a success." Shaun Danielli IGHI

Based on these findings the researchers have created a model for policy-makers, containing evidence-based ‘ingredients’ for the creation of successful initiatives and actions needed to implement them. These focus on five connected areas:

  • Eliminating child poverty, for example by improving food voucher schemes.
  • Preventing obesity in children by investing in early life, such as through culturally-tailored nutrition advice for expectant mothers.
  • Making healthy choices the easy choice, for example by managing portion sizes and reformulating food to reduce sugar content.
  • Creating healthy schools and childcare settings, including by training education and care professionals on healthy lifestyles.
  • Maximising cities’ unique assets, notably through active leadership from Mayors.

“These recommendations are not designed to be cherry-picked; addressing obesity and the environments that are fuelling it requires a blended approach of multiple interventions that reinforce one another,” said Danielli.

“Everyone has a part to play in ensuring that these initiatives are a success, but we are calling on Mayors to use their leadership and influence as a lever to enact lasting change, which we urgently need to secure a healthier future for citizens around the world.”


Justine Alford

Justine Alford
Institute of Global Health Innovation

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