Impact of Replacing Meat With Walnuts: Results of an NHANES Modeling Study

OBJECTIVES: To assess the impact of replacing meat with walnuts in a dose escalation manner in the usual US dietary intake pattern. METHODS: Food modeling was implemented in the nationally representative 2015–2018 National Health and Examination Survey (NHANES) in a population of 5,807 adults, 19 years and older of no-nut consumers. Walnuts replaced meat in a dose escalating manner (i.e., 0.5, 1, 1.5, and 2 oz equivalents per day) in the usual dietary intake in this modeling study. Diet quality was estimated using the population ratio method of the Healthy Eating Index (HEI-2015). The usual intake of nutrients was estimated using the National Cancer Institute (NCI) method. Significant differences were determined using non-overlapping 95% CIs. RESULTS: Replacing meat at any dose level with walnuts significantly improved the mean intake of fiber, magnesium, omega 3 while reducing the cholesterol intake. Further, vitamin B12 intake was significantly reduced while no significant decline in iron intake was observed. Diet quality in the modeled diets (after replacing meat with walnuts) was significantly higher compared to diet quality in the usual diet. Better diet quality scores were mainly driven by strong improvements in the HEI components “Seafood and Plant Protein” and “Fatty Acid Ratio.” CONCLUSIONS: The partial replacement of meat with walnuts improved overall diet quality and increased the intake of magnesium, fiber, and omega 3 but adversely affected vitamin B12. FUNDING SOURCES: This study was funded by the California Walnut Commission.