According to the latest WHO Global Health Observatory data, collated in 2016, more than 1·9 billion adults were overweight, with 650 million of these individuals being obese. The global prevalence of obesity nearly tripled between 1975 and 2016, with substantial rises in most countries, including those deemed to be low-income and middle-income nations. As such, the global spread of obesity has been labelled a pandemic, albeit one with a slower onset of cases and detrimental effects than the 2009 H1N1 pandemic or the COVID-19 pandemic.
For World Digestive Health Day 2021, held on May 29, the World Gastroenterology Organisation has partnered with The International Federation for the Surgery of Obesity and Metabolic Disorders to raise awareness of obesity as an ongoing pandemic. In the context of the worldwide effects of COVID-19, it is easy to appreciate why attention on global obesity, a crisis that has been developing insidiously for decades, has been reduced. Yet, the stakes remain as high as ever: the WHO estimate that at least 2·8 million people die each year as a result of being overweight or obese.
Efforts to address the obesity pandemic are complicated by many factors. At the level of the individual, the vast network of biological, psychological, and local environmental factors—often difficult to measure—that influence energy balance present a far more intricate causal mechanism than the single infectious agent causing COVID-19. This inherent complexity is too often dismissed in favour of viewing overweight and obesity as an issue of willpower, a trope wielded by industry to dismiss regulatory action in favour of personal responsibility. These arguments hold no water: it is implausible that a sudden and simultaneous decline in willpower could explain the concurrent increased prevalence of obesity across age, sex, and ethnic groups. Individual-focused and stigmatising perspectives are not just the domain of groups with commercial interests. A comparison of language used in the 2019 NHS long-term plan revealed use of a pessimistic, fearful, and condition-first narrative when discussing obesity, in contrast to optimistic, hopeful, and person-first language used when discussing cancer. Such negative communication, although not intentional, reflects the pervasive nature of the subconscious stigma surrounding obesity.
At a population level, changes in obesity prevalence can only be explained by broad environmental change, given the stasis of human biology over the same time frame. The past few decades have seen enormous shifts in the global food system, with billions of people now routinely exposed to high-energy processed food and drinks, marketed with increasing sophistication by multinational corporations. Non-food factors, such as the built environment and cultural preferences, probably act as national and regional modifiers. Accordingly, it is difficult to see how interventions focused on the individual—eg, weight-loss programmes or healthy eating campaigns—can succeed without policies to alter upstream environmental drivers.
Early in the COVID-19 pandemic it became clear that there were considerable interactions with the obesity pandemic. For instance, obesity was quickly found to be associated with worse COVID-19 clinical outcomes. Conversely, there are suggestions the COVID-19 pandemic has led to a worsening of diets, inactivity, and weight-loss treatment interruptions, particularly in deprived sectors of society. Unsurprisingly, food and drinks companies have sought to leverage the pandemic to sell products. A report by the NCD Alliance, published in September, 2020, detailed hundreds of examples of pandemic-tailored stunts and marketing campaigns by industry.
There are some notes of positivity. In July, 2020, the UK Government introduced a number of long-campaigned-for policies, including advertisement and promotional deal restrictions for foods high in fat, sugar, and salt, and launched a new healthy eating and weight loss campaign. This strategy, pitched as a way to “beat coronavirus (COVID-19) and protect the NHS”, was met with cautious optimism by leading public health figures. However, there were concerns that interventions might still reflect an emphasis on personal responsibility over curbing of industry influences, embodied by the Government's “country urged to lose weight” rhetoric. The fresh impetus provided to efforts to reduce obesity by the COVID-19 pandemic is welcome, even if it is only the result of earlier inaction. Maintaining and building on this momentum, and ensuring that similar progress is made on a global scale with international co-operation, will be vital to securing true progress on obesity.
© 2021 Adam Hart-Davis/Science Photo Library