The NHANES protocol was approved by the National Center for Health Statistics Research Ethics Review Board and all participants provided informed consent.
Data were obtained from the United States Department of Agriculture, Agricultural Research Service’s (USDA-ARS) 2007–2008 What We Eat in America (WWEIA) survey, which comprises the dietary intake component of the National Health and Nutrition Examination Survey (NHANES) 2007–2008. The WWEIA survey consists of two non-consecutive 24-hr recalls; the first completed in-person and the second by phone. For the purposes of this study, foods reported in the first recall by 8 528 individuals two years and older were included. Individuals age 12 and over reported their own diet and caregivers provided and assisted in recalls by children aged 2–12. Complete information on WWEIA can be found elsewhere . The total food consumption files include all single ingredient as well as composite foods and mixed dishes that were reported by the survey respondents  First, to categorize food amounts into the five MyPlate and two additional food groups, the USDA-ARS MyPyramid Equivalents Database for 2.0 for USDA Survey Foods, 2003–2004  and its supplement (released March 2012) was employed. The MPED database was specifically designed to translate the amounts of foods reported by participants in the WWEIA into equivalent servings of the 32 MyPyramid major and sub groups, including “Discretionary solid fat” and “Added sugars”. Although the simpler MyPlate icon has replaced the MyPyramid food guidance icon, the major food groups are identical.
Each food description is linked to a 8-digit food code, where the first digit identifies one of the nine major food groups (1 = Milk and Milk Products, 2 = Meat, Poultry, Fish, and Mixtures, 3 = Eggs, 4 = Dry Beans, Peas, Other Legumes, Nuts, and Seeds, 5 = Grain Products, 6 = Fruits, 7 = Vegetables, 8 = Fats, Oils, and Salad Dressings, 9 = Sugars, Sweets, and Beverages), the second digit indicates subgroups within each major food group and mixed foods, and the third and subsequent digits provide ever-more detailed discriminations until the level of individual food items. For this analysis, food codes were grouped by the primary level of coding to ascertain intake of the main MyPlate food groups, Vegetables, Grains, Protein Foods, Fruits and Dairy. Groups 2, 3, and 4 were combined into the Protein Foods group. Foods categorized as Fats, Oils and Salad Dressings and Sugars, Sweets, and Beverages group are not part of the MyPlate recommendations, but are of public health significance and were therefore presented separately. The Fats, Oils and Salad Dressing group includes fats that are solid at room temperature (SoF), including naturally-occurring fats, mostly from animal products, and hydrogenated vegetable oils. It also includes solid fats, such as butter and solid margarine that are added at the discretion of the consumer. Oils include naturally-occurring oils such as those nuts and seeds, non-hydrogenated vegetable oils, salad dressings, and soft margarines. The Sugars, Sweets and Beverage group includes candies, sweet desserts, sugar added at the table at the table, sugar-sweetened beverages, water, tea and coffee. Sugar from fruits is not included.
As the DGA recommendations pertain to individuals aged two and over, baby foods, formula and breast milk were excluded, resulting in an analytical sample of 4 046 unique foods reported by 8 527 respondents a total of 135 934 times. All foods consumed by the sample population were categorized as containing SoF (=1), AS (=1) or both (=2). We also include a category of “either or both” as many foods contain both SoF and AS. Tertiles of SoF and AS in each category are presented to show an approximate range of values within food group categories. The amount of SoFAS in each food was not calculated as no specific maximum recommended amount of SoFAS in any given food has been established. For instance, a dairy food may have 10 grams of AS, which would be considered excessive for a person who consumes many other foods high in AS, but could be an appropriate addition to a healthy diet for a person consuming few other high-AS foods. Thus, in contrast to other studies examining the sources of SoFAS at the level of individual diet, this study provides an overview of food choice at the aggregate level. Sampling weights were used to adjust estimated results to maintain the nationally representative character of the data. Weighted proportions of the foods in each of the food groups and their SoF, AS, and SoFAS presence were calculated.