AUTHOR=Kim Hyeon-Ki , Chijiki Hanako , Fukazawa Mayuko , Okubo Jin , Ozaki Mamiho , Nanba Takuya , Higashi Seiichirou , Shioyama Miho , Takahashi Masaki , Nakaoka Takashi , Shibata Shigenobu 

TITLE=Supplementation of Protein at Breakfast Rather Than at Dinner and Lunch Is Effective on Skeletal Muscle Mass in Older Adults

JOURNAL=Frontiers in Nutrition

VOLUME=8

YEAR=2021

URL=https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2021.797004

DOI=10.3389/fnut.2021.797004

ISSN=2296-861X

ABSTRACT=<p><bold>Background:</bold> The effects of different intake patterns of meal protein on muscle mass have not been clarified. We cross-sectionally and longitudinally examined the effect of different timing of protein intake on sarcopenia-related factors in older adults.</p><p><bold>Methods:</bold> This cross-sectional study 1 included 219 (male, <italic>n</italic> = 69, female, <italic>n</italic> = 150) elderly subjects aged ≥65 years. Subjects who consumed more protein at breakfast than at dinner were grouped into the morning group (MG, <italic>n</italic> = 76; male, <italic>n</italic> = 26; female, <italic>n</italic> = 50), and those who consumed more protein at dinner than at breakfast were grouped into the evening group (EG, <italic>n</italic> = 143; male, <italic>n</italic> = 43; female, <italic>n</italic> = 100). In cross-sectional study 2-1 (female, <italic>n</italic> = 125), the subjects were classified into four groups according to the number of meals with sufficient protein intake. In cross-sectional studies 2-2 (female, <italic>n</italic> = 125) and 2-3 (female, <italic>n</italic> = 27), the subjects were classified into eight groups and three groups according to whether they had consumed sufficient protein at three meals; sarcopenia-related factors were compared. The intervention study was a placebo-controlled, double-blind, randomized controlled trial that included 40 elderly women with low daily breakfast protein intake. The subjects were divided into four groups: morning protein and placebo intake groups and evening protein and placebo intake groups. Each group consumed the test food (containing 10 g milk protein) or placebo in the morning or evening for 12 weeks. Blood indices and physical function were assessed before and after the intervention.</p><p><bold>Results:</bold> Comparing all subjects, MG showed significantly higher handgrip strength than did EG (<italic>P</italic> &lt; 0.05). The higher ratio of morning protein intake relative to the total protein intake, the better the muscle mass (<italic>r</italic> = 0.452, <italic>P</italic> &lt; 0.05) and handgrip strength (<italic>r</italic> = 0.383, <italic>P</italic> &lt; 0.05). The intervention study showed an increase in muscle mass with the intake of milk protein in the morning rather than in the evening (<italic>P</italic> &lt; 0.05).</p><p><bold>Conclusions:</bold> Protein intake at breakfast might have relatively stronger effects on skeletal muscle mass than at lunch and dinner.</p>