Diet and Lifestyle Beat Multimorbidity Across the Lifespan

Multimorbidity — defined as the coexistence of two or more chronic conditions in one individual — has emerged as one of the most pressing challenges in modern medicine and public health. As populations age and chronic disease rates rise globally, conventional single-disease treatment models are increasingly inadequate. This editorial introduces a special issue stemming from the Nutrition Society's 2023 Winter Conference, held at the Royal Society in London, which centred on diet and lifestyle strategies for preventing and managing multimorbidity.

The conference was structured around four major symposia. The first explored prevention pathways across the lifecourse, recognising that risk accumulates from early life through old age. The second examined how ageing itself contributes to multimorbidity risk, acknowledging biological mechanisms such as inflammation and metabolic dysfunction. The third addressed the gut-brain-heart axis, a rapidly evolving area linking microbiome health to cardiovascular and neurological outcomes.

The fourth symposium spotlighted emerging technologies, particularly machine learning and precision nutrition, as tools for personalising dietary interventions and overcoming the heterogeneity that makes multimorbidity so difficult to study and treat. These approaches hold promise for identifying which individuals are most likely to benefit from specific dietary patterns or interventions.

The conference's opening plenary set the intellectual tone by calling for more sophisticated diet and lifestyle research frameworks capable of capturing the complexity of multimorbidity. The closing plenary shifted toward actionable policy, highlighting key dietary risk factors — such as poor diet quality, ultra-processed food consumption, and nutritional deficiencies — and the population-level strategies needed to address them.

This editorial serves as an important orientation document for the field. Its primary limitation is that it summarises conference content rather than presenting original research findings, meaning specific data and effect sizes are not yet available in this overview alone.