Background: Although daily protein intake (PI) has been reported to be essential for regulating muscle mass, the distribution of daily PI in individuals is typically the lowest at breakfast and skewed toward dinner. Skewed protein intake patterns and inadequate PI at breakfast were reported to be negative factors for muscle maintenance.
Objectives: This study examined whether a protein-enriched meal at breakfast is more effective for muscle accretion compared with the typical skewed PI pattern.
Methods: This 12-wk, parallel-group, randomized clinical trial included 26 men (means ± SEs; age: 20.8 ± 0.4 y; BMI: 21.8 ± 0.4 kg/m2). The "high breakfast" (HBR) group (n = 12) consumed a protein-enriched meal at breakfast providing a PI of 0.33 g/kg body weight (BW); their PI at lunch (0.46 g/kg BW) and dinner (0.48 g/kg BW) provided an adequate overall daily PI (1.30 g/kg BW/d). The "low breakfast" (LBR) group (n = 14) consumed 0.12 g protein/kg BW at breakfast; intakes at lunch (0.45 g/kg BW) and dinner (0.83 g/kg BW) yielded the same daily PI as in the HBR group. The participants performed supervised resistance training (RT) 3 times per week (75-80% 1-repetition maximum; 3 sets × 10 repetitions). DXA was used to measure the primary outcome variable, that is, total lean soft tissue mass (LTM).
Results: The total LTM at baseline did not differ between the HBR (52.4 ± 1.3 kg) and LBR (53.4 ± 1.2 kg) groups. After the intervention, increases in total LTM were significant in both groups, with that in the HBR group (2.5 ± 0.3 kg) tending to be greater than that in the LBR group (1.8 ± 0.3 kg) (P = 0.06), with a large effect size (Cohen d = 0.795).
Conclusions: For RT-induced muscle hypertrophy in healthy young men, consuming a protein-enriched meal at breakfast and less protein at dinner while achieving an adequate overall PI is more effective than consuming more protein at dinner.This study was registered at University hospital Medical Information Network (UMIN) Clinical Trials Registry as UMIN000037583 (https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000042763).
Keywords: muscle hypertrophy; protein distribution; protein intake; resistance training; young subjects.
Copyright © The Author(s) on behalf of the American Society for Nutrition 2020.
Protein Supplementation at Breakfast and Lunch for 24 Weeks beyond Habitual Intakes Increases Whole-Body Lean Tissue Mass in Healthy Older Adults.J Nutr. 2016 Jan;146(1):65-9. doi: 10.3945/jn.115.219022. Epub 2015 Nov 18. J Nutr. 2016. PMID: 26581685 Clinical Trial.
Within-day protein distribution does not influence body composition responses during weight loss in resistance-training adults who are overweight.Am J Clin Nutr. 2017 Nov;106(5):1190-1196. doi: 10.3945/ajcn.117.158246. Epub 2017 Sep 13. Am J Clin Nutr. 2017. PMID: 28903957 Free PMC article. Clinical Trial.
Beyond the dinner table: who's having breakfast, lunch and dinner family meals and which meals are associated with better diet quality and BMI in pre-school children?Public Health Nutr. 2017 Dec;20(18):3275-3284. doi: 10.1017/S1368980017002348. Epub 2017 Sep 14. Public Health Nutr. 2017. PMID: 28903804 Free PMC article.
International society of sports nutrition position stand: nutrient timing.J Int Soc Sports Nutr. 2017 Aug 29;14:33. doi: 10.1186/s12970-017-0189-4. eCollection 2017. J Int Soc Sports Nutr. 2017. PMID: 28919842 Free PMC article. Review.
Protein Distribution and Muscle-Related Outcomes: Does the Evidence Support the Concept?Nutrients. 2020 May 16;12(5):E1441. doi: 10.3390/nu12051441. Nutrients. 2020. PMID: 32429355 Review.
Cited by 1 article
Acute Effect of the Timing of Resistance Exercise and Nutrient Intake on Muscle Protein Breakdown.Nutrients. 2020 Apr 22;12(4):1177. doi: 10.3390/nu12041177. Nutrients. 2020. PMID: 32331476 Free PMC article.