Comparing the cost of essential nutrients from different food sources in the American diet using NHANES 2011-2014.

Background: One reason that some Americans do not meet nutrient needs from healthy eating patterns is cost. Food cost affects how people eat, and healthy diets tend to be more expensive. Cost is also important for diet sustainability. Sustainable eating patterns must be both nutritionally adequate and affordable. The objective of this study was to compare the cost of obtaining shortfall nutrients from different food groups to help identify cost-effective ways Americans can move towards healthy and sustainable eating patterns.

Methods: This analysis used dietary intake data from the National Health and Nutrition Examination Survey from 2011 to 2012 and 2013-2014 (n = 5876 children 2-18 years and n = 9953 adults 19-99 years). Americans' nutrient intake from food categories in "What We Eat in America" and the 2015-2020 Dietary Guidelines for Americans was determined using the Food and Nutrient Database for Dietary Studies. Food cost and the cost of nutrients were obtained from Center for Nutrition Promotion and Policy food cost database 2001-2002 and 2003-2004 (adjusted for inflation).

Results: The daily mean cost of food was $4.74 ± 0.06 for children and $6.43 ± 0.06 for adults. "Protein foods" and "mixed dishes" were the two most expensive food categories (43-45% of daily food costs), while "grains," "fruits," and "vegetables" combined accounted for ~ 18% of the daily cost, and "milk and dairy" accounted for 6-12% of total daily food costs in both adults and children. "Milk and dairy" were the least expensive dietary sources of calcium and vitamin D in the American diet, while "grains" were the least expensive sources of iron and magnesium, and "protein foods" were the least expensive sources of choline. "Fruits" and "vegetables" were the least expensive sources of potassium and vitamin C, respectively, and "snacks and sweets" were the least expensive sources of vitamin E.

Conclusion: "Milk and dairy" were inexpensive sources of three of the four nutrients of public health concern (calcium, vitamin D, and potassium), while "grains" were the least expensive source of fiber. The results of this work reinforce the importance of consuming a variety of nutrient-rich foods for cost-effective, sustainable eating patterns.