Abstract
OBJECTIVES: The 2020–2025 Dietary Guidelines for Americans encourage varying protein intake to include both animal foods and plant foods for the range of nutrients provided. The objective of this study is to estimate proportions of adults’ protein intake from animal and plant sources and the contribution of foods to each. METHODS: One day dietary intake data of adults 20+ years (N = 5017) in What We Eat in America (WWEIA), NHANES 2015–2016 were used. Proportions of protein intake from animal and plant sources were estimated from the ingredients for the foods in the Food and Nutrient Database for Dietary Studies (FNDDS) 2015–2016. Single ingredient foods such as chicken or beans were classified as 100% animal or plant, respectively. Proportions from multi-ingredient foods were determined from the amounts of animal and plant food ingredients in each item. If ingredients were not specified, the proportions from a similar food were applied. The proportions were applied to the dietary intakes to determine the population intake of protein from animal and plant sources. The WWEIA food categories were used to describe contribution of foods to animal and plant protein intake. RESULTS: Animal and plant foods accounted for 67% and 33% of total protein intake, respectively. Excluding mixed dishes, animal protein intake was contributed by dairy products (14%); meats (12%); poultry (16%); seafood (6%); cured meats (8%); and eggs (6%). Mixed dishes contributed 31% of animal protein intake. Protein from plant foods, excluding mixed dishes, was contributed by grains (24%); plant-based protein foods including legumes (4%), nuts and seeds (7%) soy products (1%); vegetables (9%); and fruit (2%). Mixed dishes accounted for 30% of plant protein intake; snacks and sweets contributed 14%. CONCLUSIONS: Although protein intake from animal sources is relatively diverse, encouraging greater variety of protein intake from plant-based protein foods appears warranted. FUNDING SOURCES: ARS-USDA.