Dietetics (from the Greek diaita, meaning "mode of life") has been implicated in the cause, cure and prevention of disease from earliest recorded history. The profession of dietetics, which is based on the philosophy that optimal nutrition is essential for the health and well-being of every person, is concerned with the science of human nutritional care; the practice of dietetics involves the application of knowledge about nutrition. Dietitians may specialize in various areas, including general practice, administration of dietetic services, community nutrition, clinical nutrition and nutrition education.

In Canada the origin of dietetics and the founding of the Canadian Dietetic Association are closely related to the history of household science at the University of Toronto where the first degree course of its kind was initiated in 1902. In 1908 the first qualified dietitian was appointed to the staff of the Hospital for Sick Children in Toronto. The American Dietetic Association then offered accredited courses for dietetic training at the University of Alberta Hospital in Edmonton and Vancouver General Hospital. Some 12 Canadian hospitals had developed similar training programs by the time the Canadian Dietetic Assocation was established in 1935, and provincial associations were already functioning in Ontario, Québec and BC.

In Canada professional competence in dietetics is determined and warranted by certification and registration by nationally affiliated provincial associations. Universities in all provinces now offer academic programs in dietetics; but, in addition, to be a qualified dietitian one must serve an approved internship or have equivalent experience.