Taking as examples several varieties of food grain featured in the dietary culture of the people of Beichuan (Northern Sichuan), this article explores how these food grains have, in accordance with their material qualities and their place in the economic life of local people, been endowed with various kinds of social and cultural symbolism. For instance, maize symbolizes the ordinary grain on which people rely for subsistence, while highland barley symbolizes the grain of Tibetans or other minority ethnic groups. Buckwheat, which in the past was seen by Han people in the area as 'the food of barbarians' has, as a consequence of more and more mountain villagers being classed as Qiang from the 1950s onwards, come to be seen by local educated people as the 'typical food of the Qiang' and as 'the grain deity of the Qiang.' By treating the practices, oral discourses and writings relating to these food grains as social representations (or texts), this article analyses the social reality (or circumstances) that simultaneously produces these representations and is modified by them, as well as analysing the processes of the transformation of that reality. In this article, social reality refers mainly to the division of people into ethnic groups (Han Chinese and barbarians; Han people and Qiang people); in the light of these divisions, people, in pursuit of superior or more secure status, tend to glorify, satirize, imitate or attach themselves to those they encounter in daily life, in conjunction with their ancestral origins or life customs, taking diet as a key element. In the Ming and Qing these representations led to the sinification of the people of Beichuan; in recent decades an analogous process has caused them to become Qiang.