Figure 1
Classification of food items in the Canadian Community Health Survey (CCHS) - Nutrition 2004 and 2015 according to the NOVA system

Figure 1 is decision tree diagram (a type of flowchart). This figure summarizes the process of how food items in the Canadian Community Nutrition Survey (CCHS) - Nutrition 2004 and 2015 were classified according to the NOVA scheme. The figure is comprised of vertically stacked boxes and arrow connectors, which indicate the different courses of action (i.e., steps) involved in the process and their outcomes.

The top three boxes describe the first step, where food items are differentiated either as basic foods or ingredients available on the Food and Ingredient Details file, or as recipes or sub-recipes on the Food Recipe Level file.

For basic foods or ingredients, the arrow connects to the third box on the left, which represents the initial classification (Phase I). This step involves classifying all basic foods and ingredients into NOVA groups and subgroups according to the food code description. This initially classified list serves as the basis of the final list of food items classified according to NOVA. This is indicated by an arrow directing to the fourth box on the left, which represents the final list of basic foods and ingredients fully classified into NOVA groups and subgroups.

For recipes and sub-recipes, the third box on the right asks whether the recipe is a “frozen meal” or “lunch kit” (“yes” or “no”). If “yes,” the arrow directs to the modification phase (Phase II). This step involves reclassifying all underlying ingredients of the recipe as ultra-processed. An elbow arrow connects this step to the fourth box on the left (i.e., the final list of food items classified into NOVA). This signals that all ingredients on the final list (generated from Phase I) that make up “frozen meal” and “lunch kit” recipes should be reclassified as ultra-processed.

If the recipe is not a “frozen meal” or “lunch kit,” then the arrow points to a box asking whether or not the recipe is a potential ultra-processed dish (“yes” or “no”). If “no,” the initial classification should be maintained. If “yes,” the reader is further asked whether the dish was prepared or consumed in a quick-service setting (“yes” or “no). (Quick-service settings are specified in the footnotes to the figure.) If “no,” then an arrow connects to the bottom right box, which indicates to maintain the initial classification. If “yes,” (i.e., the dish was consumed in a quick-service setting), the arrow connects to the bottom left box which indicates another instance of modification (Phase II), whereby all underlying ingredients are reclassified as ultra-processed. An elbow arrow connects this box to the fourth box on the left (i.e., the final list of food items classified according to NOVA).