The world faces a global nutrition crisis, most clearly evidenced by the twin pandemics of obesity and type 2 diabetes (T2DM). Yet, substantial confusion and controversy exist about optimal dietary priorities and policy approaches to address these challenges. This paper reviews the evolution of nutritional evidence, emerging areas and corresponding policy lessons to address obesity and T2DM. This includes the complexity of diet–health pathways for long-term weight maintenance and metabolic health; a need to focus on both increasing protective foods (for example, minimally processed, phytochemical-rich foods) and reducing detrimental factors (for example, refined starches, added sugars and processed meats); and critical assessment of popular diets for weight-loss and metabolic health. Emerging evidence highlights areas for further research, including those related to food processing, non-nutritive sweeteners, emulsifiers, the microbiome, flavonoids and personalized nutrition. Evidence-based, multi-sectoral policy actions to address the global nutrition crisis are shown to span several domains, including health systems, economic incentives, school and workplace environments, quality and labelling standards, and innovation and entrepreneurship.

肥胖和2型糖尿病（T2DM）的双重大流行最清楚地证明了世界面临着全球营养危机。然而，关于最佳饮食重点和应对这些挑战的政策方法仍存在大量困惑和争议。本文回顾了营养证据的发展，新兴领域以及应对肥胖和2型糖尿病的相应政策课程。这包括长期维持体重和代谢健康的饮食健康路径的复杂性；需要同时注重增加保护性食品（例如，加工最少的，富含植物化学物质的食品）和减少有害因素（例如，精制淀粉，添加的糖和加工的肉类）；对减肥和代谢健康流行饮食的严格评估。新兴证据突出了需要进一步研究的领域，包括与食品加工，非营养性甜味剂，乳化剂，微生物组，类黄酮和个性化营养有关的那些。事实证明，为解决全球营养危机而采取的基于证据的多部门政策行动涉及多个领域，包括卫生系统，经济激励措施，学校和工作场所环境，质量和标签标准以及创新和企业家精神。