In 2004, 48% of calories consumed by Canadians came from ultra-processed foods. Consumption of such foods was high amongst all socioeconomic groups, and particu-larly in children and adolescents. As a group, ultra-processed foods were grossly nutritionally inferior tonon-ultra-processed foods. After adjusting for covariates, a significant and positive relationship was found between the dietary share of ultra-processed foods and the content in carbohydrates, free sugars,total and saturated fats and energy density, while an inverse relationship was observed with the dietary content in protein,fiber, vitamins A, C, D, B6 and B12, niacin, thiamine, riboflavin, as well as zinc, iron,magnesium, calcium, phosphorus and potassium. Lowering the dietary share of ultra-processed foodsand raising consumption of hand-made meals from unprocessed or minimally processed foods wouldsubstantially improve the diet quality of Canadian.