Usual Dietary Intake of Resistant Starch in US Adults from NHANES 2015-2016

Background: Resistant starch (RS) confers many health benefits, mostly due to nonenzymatic human digestion and gut microbiota fermentation capacity. The usual intake of naturally occurring dietary RS in US adults is unclear. Objectives: This study estimated usual daily RS intake in grams per 1000 kcal in US adults by sex, age, and ethnic group, as well as the most frequent food category contributing to RS intake using data from the NHANES 2015-2016. Methods: RS content of foods consumed was matched with Food and Nutrient Database for Dietary Studies food codes. The National Cancer Institute method was used to estimate adults' usual RS intake from 2 24-h dietary recalls. Day 1 RS contribution from food groups to overall RS intake was ranked for the total sample, across age-sex categories, and across ethnic groups. Results: In total, 5139 US adults (48.4% male) had a mean daily usual intake of RS of 1.9 +/- 0.0 g/(1000 kcal.d). Males and females had a similar intake of RS [2.0 +/- 0.0 g compared with 1.9 +/- 0.0 g/(1000 kcal.d)] with no differences between sexes within the same age category. When comparing ethnic groups within each age category, the non-Hispanic white males and females had significantly lower RS intake than all other ethnic groups [range: 1.7-1.8 compared with 2.1-2.3 g RS/(1000 kcal.d), respectively], with no differences among the other ethnic groups. French fries and other fried white potatoes, rice, and beans, peas, and legumes were the most frequently consumed food categories contributing to RS intake in all adults. Conclusions: US adults should improve the intake of natural RS food sources. Increasing RS intake will improve gastrointestinal health as a prebiotic and potentially increase insulin sensitivity with adequate consumption (e.g., similar to 15 g/d).