Sustainability
India and China are two similar developing countries with huge populations, rapid economic growth and limited natural resources, therefore facing the massive pressure of ensuring food security. In this paper, we will discuss the food security situations in these two countries by studying the historical changes of food supply-demand balance with the concept of agricultural land requirements for food (LRF) from 1963–2009. LRF of a country is a function of population, per capita consumption/diet, cropping yield and cropping intensity.