Effect of Animal Protein Intake on Meeting Recommendations for Nutrient Intake among US Adults, What We Eat in...

Replacing some animal sources of protein with plant foods is encouraged. Nutrient intake may reflect changes in the protein source. The adequacy of habitual nutrient intake among US adults has not been evaluated by the level of animal protein (AP) intake.

The objective of this study was to compare food consumption and nutrient intake and adequacy among quintiles of percent AP intake.

Dietary intake data of adults 19+ y (N = 9706) from What We Eat in America, National Health and Nutrition Examination Survey 2015-2018 were used. Proportions of protein from animal and plant sources were estimated from ingredients in the Food and Nutrient Database for Dietary Studies 2015-2018, and then applied to dietary intakes. Intakes were classified by Q of percent AP. Food intake was described using the United States Department of Agriculture Food Patterns components. Usual nutrient intakes were estimated using the National Cancer Institute Method and compared with age and gender-specific Dietary Reference Intakes (DRIs). Comparisons between quintiles were made using t-tests. Results were considered significant at P < 0.01.

Total protein intake was higher as the Q of AP intake increased. Among the higher quintiles of percent AP, <1% did not meet their DRIs for protein than 17% in Q1 and 5% in Q2 (P < 0.01). In quintiles with lower compared with higher percent AP, there were significantly higher percentages not meeting DRIs for vitamins A, B12, choline, zinc, and calcium but meeting recommendations for folate, vitamin C, saturated fat, cholesterol, and fiber (P < 0.01). Among all quintiles, over one-third did not meet DRIs for fiber, vitamins A, C, D, E, K, choline, calcium, and potassium.

Replacing protein from animal sources with plant foods may result in lower intakes of protein and some nutrients but a better intake of dietary components associated with reducing chronic disease risk. The current intake of US adults indicates dietary improvements are needed, regardless of protein source.