Investigating Trends in Nutrition: Greater Intake of Fish and Plant Protein is Associated with Better Diet Quality in US Adults
Abstract Objectives Recent trends in nutritional intake have emphasized decreasing meat intake and increasing intake of whole plant-based foods as a dietary strategy that has both health and environmental benefits. National surveillance data have demonstrated that intake of fish and plant protein has increased over the past decade, but little has been done to examine the association with plant protein intake and diet quality. Dietary energy density (ED, kcal/g) is an established indicator of diet quality and is a risk factor for chronic disease. The objective of the present study was to examine the relationship between plant food intake, dietary energy density and overall diet quality. Methods Data from a nationally representative sample of 10,622 adults who participated in the 2013–2016 NHANES was analyzed. Dietary data was collected using 24HR, and intake was quantified using the USDA FPED serving equivalents. Sex-specific quartiles of energy density were calculated. All data were analyzed using SAS 9.4 survey procedures to account for the unequal sampling probability and complex survey design of the NHANES. All models are energy-adjusted and adjusted for age, sex race/ethnicity, educational attainment, and household income. Results In this sample of US adults, dietary energy density was associated with higher intakes of plant foods, including fruits, vegetables and plant proteins (all P < 0.0001). Individuals in with low-ED diets had significantly higher intakes of legume protein foods (0.63 vs 0.22 oz eq, P = 0.0001) and soy protein foods (P = 0.03). Individuals with low-ED diets also consumed nearly double the amount of fiber, as well as significantly higher intakes of B-carotene (4006 vs 950 mcg) and lycopene (6742 vs. 2404 mcg) than those with energy-dense diets (p's < 0.0001). Conversely, individuals with high-ED diets had significantly higher intake of processed meats (1.0 vs. 0.66 oz eq, P < 0.0001); cheese products (P < 0.0001); solid, saturated and total fat; and lower intakes of seafood (all P < 0.01). No association between energy density and intake of total animal source proteins, eggs nor total dairy intake was observed. Conclusions Plant protein intake is associated with lower dietary ED and higher diet quality in adults. Dietary strategies to increase plant food intake may be useful for health promotion and disease prevention. Funding Sources None.