Percutaneous coronary intervention (PCI) is increasingly used in revascularisation of patients with left main coronary artery disease in place of the standard treatment, coronary artery bypass grafting (CABG). The NOBLE trial aimed to evaluate whether PCI was non-inferior to CABG in the treatment of left main coronary artery disease and reported outcomes after a median follow-up of 3·1 years. We now report updated 5-year outcomes of the trial.

Malnutrition has historically been researched and addressed within two distinct silos, focusing either on undernutrition, food insecurity, and micronutrient deficiencies, or on overweight, obesity, and dietary excess. However, through rapid global nutrition transition, an increasing proportion of individuals are exposed to different forms of malnutrition during the life course and have the double burden of malnutrition (DBM) directly. Long-lasting effects of malnutrition in early life can be attributed to interconnected biological pathways, involving imbalance of the gut microbiome, inflammation, metabolic dysregulation, and impaired insulin signalling. Life-course exposure to early undernutrition followed by later overweight increases the risk of non-communicable disease, by imposing a high metabolic load on a depleted capacity for homoeostasis, and in women increases the risk of childbirth complications. These life-course trajectories are shaped both by societal driving factors-ie, rapidly changing diets, norms of eating, and physical activity patterns-and by broader ecological factors such as pathogen burden and extrinsic mortality risk. Mitigation of the DBM will require major societal shifts regarding nutrition and public health, to implement comprehensive change that is sustained over decades, and scaled up into the entire global food system.

Actions to address different forms of malnutrition are typically managed by separate communities, policies, programmes, governance structures, and funding streams. By contrast, double-duty actions, which aim to simultaneously tackle both undernutrition and problems of overweight, obesity, and diet-related non-communicable diseases (DR-NCDs) have been proposed as a way to effectively address malnutrition in all its forms in a more holisitic way. This Series paper identifies ten double-duty actions that have strong potential to reduce the risk of both undernutrition, obesity, and DR-NCDs. It does so by summarising evidence on common drivers of different forms of malnutrition; documenting examples of unintended harm caused by some undernutrition-focused programmes on obesity and DR-NCDs; and highlighting examples of double-duty actions to tackle multiple forms of malnutrition. We find that undernutrition, obesity, and DR-NCDs are intrinsically linked through early-life nutrition, diet diversity, food environments, and socioeconomic factors. Some evidence shows that programmes focused on undernutrition have raised risks of poor quality diets, obesity, and DR-NCDs, especially in countries undergoing a rapid nutrition transition. This Series paper builds on this evidence to develop a framework to guide the design of double-duty approaches and strategies, and defines the first steps needed to deliver them. With a clear package of double-duty actions now identified, there is an urgent need to move forward with double-duty actions to address malnutrition in all its forms.

The double burden of malnutrition (DBM), defined as the simultaneous manifestation of both undernutrition and overweight and obesity, affects most low-income and middle-income countries (LMICs). This Series paper describes the dynamics of the DBM in LMICs and how it differs by socioeconomic level. This Series paper shows that the DBM has increased in the poorest LMICs, mainly due to overweight and obesity increases. Indonesia is the largest country with a severe DBM, but many other Asian and sub-Saharan African countries also face this problem. We also discuss that overweight increases are mainly due to very rapid changes in the food system, particularly the availability of cheap ultra-processed food and beverages in LMICs, and major reductions in physical activity at work, transportation, home, and even leisure due to introductions of activity-saving technologies. Understanding that the lowest income LMICs face severe levels of the DBM and that the major direct cause is rapid increases in overweight allows identifying selected crucial drivers and possible options for addressing the DBM at all levels.

Observations from many countries indicate that multiple forms of malnutrition might coexist in a country, a household, and an individual. In this Series, the double burden of malnutrition (DBM) encompasses undernutrition in the form of stunting, and overweight and obesity. Health effects of the DBM include those associated with both undernutrition, such as impaired childhood development and greater susceptibility to infectious diseases, and overweight, especially in terms of increased risk of added visceral fat and increased risk of non-communicable diseases. These health effects have not been translated into economic costs for individuals and economies in the form of lost wages and productivity, as well as higher medical expenses. We summarise the existing approaches to modelling the economic effects of malnutrition and point out the weaknesses of these approaches for measuring economic losses from the DBM. Where population needs suggest that nutrition interventions take into account the DBM, economic evaluation can guide the choice of so-called double-duty interventions as an alternative to separate programming for stunting and overweight. We address the evidence gap with an economic analysis of the costs and benefits of an illustrative double-duty intervention that addresses both stunting and overweight in children aged 4 years and older by providing school meals with improved quality of diet. We assess the plausibility of our method and discuss how improved data and models can generate better estimates. Double-duty interventions could save money and be more efficient than single-duty interventions.