Table 2.

Decisions made to classify What We Eat in America, NHANES, according to the Nova classification system in the reference approach

Decision	Description	Examples
Decision A: Likely homemade dishes classified at the SR code level	Food codes that were likely to be homemade or artisanal and linked to a list of scratch ingredient SR codes were classified at the SR code level (referred to as “disaggregated mixed dishes”). Mixed dishes were assumed to be homemade unless the food item description or SR codes clearly suggested that it was ready-to-eat.	-“Beef stroganoff” and “Cookie, chocolate chip, made from home recipe or purchased at a bakery” were classified at the SR code level -Foods likely purchased as ready-to-eat/heat/drink items, such as “Milk, fat-free (skim),” “Cereal (Kellogg’s Apple Jacks)” or “Lasagna with meat, canned,” were classified at the food code level
Decision B: More conservative classification	Absence of needed descriptive data for food codes or discrepancies between coders regarding the degree of processing were generally solved by opting for the lesser degree of processing (conservative criterion), with some exceptions including bread, ready-to-eat cereal, and salty snacks.	-Cured meats were classified as processed (group 3), as guided by the Nova classification system, although some would be considered ultraprocessed. Food code “Pork bacon, NS as to fresh, smoked or cured, cooked” was classified as processed, although some brands such as “Sliced bacon, hickory smoked” should be considered ultraprocessed because of sodium nitrite and flavorings in the following ingredient list: pork cured with water, salt, cane, and brown sugar, sodium phosphate, sodium erythorbate, sodium nitrite, flavorings (source: USDA Branded Food Products Database) -Jellies, jams, and applesauce were classified as processed foods (although some brands could be ultraprocessed) -Animal fats such as creams and evaporated milks were classified as processed culinary ingredients (although some brands could be ultraprocessed) -Cottage and cream cheese were classified as processed cheese (although some brands could be ultraprocessed)
Decision C: Classifying breakfast cereals and salty snacks as ultraprocessed	Ready-to-eat breakfast cereals and salty snacks were generally classified as ultraprocessed, as guided by the Nova classification system, although some specific brands may be processed.	-For example, food code “Cereal, Corn Flakes” was classified as ultraprocessed consistent with the ingredient list of Kellogg’s Corn Flakes containing malt flavor (milled corn, sugar, contains ≤2% of malt flavor, salt, BHT for freshness, vitamins, and minerals) or Springfield Cereal, Corn Flakes containing high fructose corn syrup (milled corn, sugar, salt, malt syrup, high fructose corn syrup, vitamins and minerals), although some brands might be processed, such as Barbara’s Cereal, Corn Flakes (organic corn, organic fruit juice concentrate (pear or apple), sea salt) -Regarding salty snacks, although Corn Nuts Crunchy Corn Kernels are ultraprocessed because of monosodium glutamate and natural flavor in their ingredient list (corn, salt, corn oil, contains <2% of maltodextrin, spice, onion powder, garlic powder, tomato powder, monosodium glutamate, citric acid, paprika extract (for color), natural flavor), Corn Nuts Original Crunchy Corn Kernels (corn, corn oil, salt) would be processed
Decision D: Classifying industrial bread as ultraprocessed	Regarding bread, the Nova classification distinguishes between handmade bread (either homemade or made in restaurants or artisanal bakeries) and industrial bread (made in industrial bakeries or factories), either processed (when manufactured with ingredients used in culinary preparations) or ultraprocessed (when manufactured with food substances not used in culinary preparations). Because of the large amount of industrial breads with unknown ingredients in the NHANES dietary data (∼3.7% of all industrial bread had fully known ingredients in cycle 2009–2010) and the very low consumption of processed breads when ingredients were reported (∼2.3% of industrial breads were processed in cycle 2009–2010), all industrial bread were classified as ultraprocessed foods [26].	—
Decision E: Classifying nondisaggregated mixed dishes based on principal ingredient	Potential homemade mixed dishes with unlisted scratch ingredients (because Food Code was linked to recipe/mixed dish and not to a list of scratch ingredient SR codes) were classified based on expected principal ingredients.	-For example, an SR code “Restaurant, Chinese, sesame chicken” (36633) used to code the “Sesame chicken” (food code 27146360), was classified as “meat” within unprocessed/minimally processed foods
Decision F: Using “combination food type” and “source of food” to review Nova classification	Participant-specific “Combination Food Type” and “Source of food” variables from the dietary recall were used to check the appropriateness of Nova classification. Some items were reclassified based on the information provided by these variables, if needed. Some food codes (mainly mixed dishes, including sauces and cakes, cookies, and pies) initially classified at the SR code level were reclassified as ultraprocessed foods at the food code level if consumed as “frozen meals” or “lunchables” (combination food types) or from “restaurant fast food/pizza” or “vending machine” (food source). The classification of most food items, however, did not change (e.g., a raw apple from a fast food place or vending machine remained classified as an unprocessed/minimally processed food).	-For example, “Rice with vegetables (including carrots, broccoli, and/or dark-green leafy), no sauce, NS as to fat added in cooking” was initially classified at the SR code level under the assumption that it was a homemade recipe. This was reclassified at the food code level as an ultraprocessed ready-to-eat meal when reported as a “frozen meal” -“Coffee cake, yeast type, made from home recipe or purchased at a bakery” coded according to SR codes was reclassified as ultraprocessed “cake” when consumed at a “restaurant fast food/pizza”

NS, not specified. SR code, standard reference code or ingredient code from the USDA National Nutrient Database for Standard Reference.