The Lancet Commission on improving population health post-COVID-19

An increasing number of national and international commitments have failed to reduce three intimately interconnected major global threats to population health: non-communicable diseases, outbreaks of infectious diseases, and environmental degradation.

Non-communicable diseases cause more than 43 million deaths globally every year, of which 18 million are of people younger than 70 years. More than 70% of these deaths occur in low-income and middle-income countries (LMICs). To date, the official number of COVID-19 cases globally is more than 775 million, with more than 7 million deaths, although the absolute figures are likely to be far higher due to under-reporting. Environmental degradation is unravelling complex ecosystems, setting the world on a path to mass extinction, with the climate crisis creating an existential threat to human survival.

The Lancet Commission on improving population health post-COVID-19 was established to draw attention to the interactions between these three threats, the frequently shared structural factors underpinning them, and the opportunities for synergistic actions to address them. Having identified that the three systems of physical environment and transport, agriculture and food, and energy, underpin the three primary threats to population health, the Commissioners agreed upon three aims for the Commission to generate and synthesise evidence on actions needed to achieve: (1) healthy and sustainable physical environment and transport systems; (2) healthy and sustainable agriculture and food systems; and (3) healthy and sustainable energy systems. These aims were used to create a framework to agree a set of objectives via a two-stage survey and modified Delphi exercise that resulted in a final list of ten objectives which were clustered under each of the three aims. In addition, we conducted supporting work: a rapid review of the evidence on drivers of, and policy levers for addressing, the three threats of non-communicable diseases (NCDs), communicable disease, and environmental degradation; an expert elicitation exercise using semi-structured interviews with 26 international experts to identify potential actions; and two pieces of economic modelling on the impact of carbon pricing on agriculture and land use, as well as land use and transport. By synthesising evidence obtained from each of these sources we identified a set of recommendations for actions to take place within and, in many cases, across the three systems of physical environment and transport, agriculture and land use, and energy. Equity is a central concern of our Commission, and all actions were considered in terms of their potential effects on inequalities, as well as risks of other harmful unintended consequences. Where this was the case, we identified potential ways in which any such harms could be mitigated.

We identified that these three threats to population health are caused by many shared and interacting factors. For example, the clearance of vast areas of land globally to support high levels of palm oil production reduces the capacity of the land to retain carbon, and excessive consumption of ultraprocessed foods containing palm oil contributes to non-communicable diseases (such as obesity and type 2 diabetes), which are major risk factors for morbidity and mortality from infectious diseases, including COVID-19. Simultaneously, the destruction of ecosystems and the loss of habitats increase the likelihood of interactions between wild animals and humans, which in turn increase the risk of new zoonotic diseases transferring from animals to humans. Simultaneously, global heating drives an increase in disease vectors, such as those for malaria and dengue, and air pollution creates an epidemic of respiratory disease.

The drivers of these threats are underpinned by political systems that prioritise economic growth over population health and the natural environment, undermining economies through increased health-care costs and reduced human productivity. Across these threats, people with the lowest income experience the greatest harms. Reducing these threats requires a global shift in the behaviour of populations, including eating healthier and more sustainable diets, drinking less or no alcohol, not smoking, and increasing levels of physical activity. These behaviours are largely cued, reinforced, and maintained by physical, economic, digital, and social environments over which individuals have little control. Exhorting individuals to change their behaviour is therefore an ineffective strategy for the magnitude and scale of change that is required. Changing these behaviours necessitates changing the environments that shape them, requiring action largely by governments and business actors to transform the conditions that determine population health.

Achieving the necessary political action in the face of growing political populism and geopolitical instability globally is a major challenge. There are, however, some positive signs, including: increases in the affordability of public transport in cities around the world; restrictions on advertising and marketing of ultra-processed foods coupled with mandatory warning labels led by countries in Latin America; and increases in renewable energy generation globally. However, these changes are not occurring at either the large scale or the rapid speed that is needed.

This Commission provides a set of recommendations that, if implemented, could have a major impact on increasing both the scale and speed of action necessary to address some of the greatest threats to population health (panel 1).