This chapter focuses on the energy and nutritional needs of humans and discusses the global concerns in nutrition. It examines the evidence around the issue of 'is there food for all' and 'what comes first: food security or food safety?' The chapter illustrates these issues of food security and food safety with research on two crops, potato and cassava. It outlines how nutritionists and those working with nutrition in an agricultural context can take action to affect food and nutrition policy. The ever ongoing problem is the relation between food production, population growth and food availability. In the end of the 18th century, Malthus commented on the imbalance between population growth and global food production. Throughout the centuries, the energy flows and carrying capacities of yields in food production have changed from foraging and pastoralism to development of agricultural production from shifting cultivation via traditional farming to modern mechanized farming.