Scale up 'we are what we eat' and nutrition is revealed as an aspect of world governance. The quality and nature of food systems has always tended to determine not only the health and welfare but also the fate of nations. The independence of nations depends on their development of their own human and natural resources, including food systems, which, if resilient, are indigenous, traditional, or evolved over time to climate, terrain and culture. Rapid adoption of untested or foreign food systems is hazardous not only to health, but also to security and sovereignty. Immediate gain may cause permanent loss. Dietary guidelines that recommend strange foods are liable to disrupt previous established food cultures. Since the 1960s the 'green revolution' has increased crop yield, and has also accelerated the exodus of hundreds of millions of farmers and their families from the land into lives of misery in mega-cities. This is a root cause of increased global inequity, instability and violence. 'Free trade' of food, in which value is determined by price, is imposed by dominant governments in alliance with industry when they believe they can thereby control the markets. The World Trade Organization and other agencies coordinate the work of transnational corporations that are the modern equivalents of the East India companies. Scientists should consider the wider dimensions of their work, nutrition scientists not least, because of the key place of food systems in all societies.