Association of Dietary Protein Intake and Grip Strength Among Adults Aged 19+ Years: NHANES 2011-2014 Analysis.

BACKGROUND

Research on the role of protein in the diet has evolved beyond a focus on quantity to include the impact of its quality and distribution across meal times in an effort to optimize dietary protein recommendations.

OBJECTIVE

To determine the association of dietary protein amount, type, and intake pattern with grip strength in adults.

DESIGN

Data from the National Health and Nutrition Examination Survey (NHANES) 2011-2014 for adults 19 + years ( = 9,214) were used with exclusions for pregnant and lactating women. Intakes of dietary total protein (TP), animal protein (AP, including dairy), plant protein (PP), and leucine (Leu) were determined using day 1 24 h dietary recall data after adjusting for the complex sample design of NHANES. Regression analyses were used to assess the association of dietary protein and leucine intake quartiles, and whether consuming > 20 g of dietary protein at one or more meals was related to grip strength with adjustment for age, gender, and ethnicity.

RESULTS

Mean intake of TP among adults aged 19 + years was 83.6 ± 0.5 g/day, and 2/3rd of this was from animal sources (including dairy). Grip strength increased ( < 0.05) with increasing quartiles of TP, AP, PP, and leucine among all adults 19 + years (β = 1.340.19, 1.27 ± 0.19, 0.76 ± 0.20, and 1.33 ± 0.23, respectively), 19-50 years (β = 1.14 ± 0.27, 1.06 ± 0.25, 0.77 ± 0.30, and 1.18 ± 0.27, respectively), and 51 + years (β = 0.95 ± 0.26, 1.08 ± 0.27, and 1.05 ± 0.27, respectively, for TP, AP, and Leu); however, the increase was more pronounced for AP than PP. Grip strength also increased ( < 0.05) with increasing the number of meal occasions containing > 20 g of dietary protein (β = 1.50 ± 0.20, 1.41 ± 0.25, and 0.91 ± 0.37 for 19+, 19-50, and 51 + years, respectively), and significant increases were detected for two meals compared to zero meals.

CONCLUSION

Dietary protein quantity, quality, and distribution should be considered collectively when looking to optimize protein intake to support muscle strength and function.