The rapidly changing and interdependent world under the mega-force of globalization presents unique challenges and opportunities for public health. Focusing on the example of type 2 diabetes, I argue that an appreciation for the evolution of demographic and economic contexts is essential to appropriately address today's dynamic and complex health challenges. For the vast majority of the past 2000 years, India and China were the world's largest economies until the rise of western European nations in the 18th century and later the USA. In the case of India, inflation-adjusted per capita income remained flat between 1700 and 1950, while in the same period that of the UK grew more than 7-fold, although the population of the UK relatively grew 3-times faster than that of India in the same period. This 250-year gap in industrial and economic development may be central to understanding the large burden of diabetes among individuals of Indian descent, and should be taken into account in a wider context to understand the divergence in health development between India and parts of the world which benefited from early industrial progress and accompanying improvements in food supply, hygiene and living conditions. Lessons from high-income countries support a strong emphasis on public health to achieve important populationwide health gains, and offer insights into the broader determinants of health such as economic and food security, equity, urban infrastructure, health-promoting environments, and access to high-quality health systems. Critical to contemporary public health is also strong data systems and evidence-based decision-making.