Evenly Distributed Protein Intake over 3 Meals May Help with Muscle Maintenance

 

    Keeping muscle mass is important for maintaining good health. Muscle mass is going through constant synthesis and breakdown. Daily protein intake is essential for regulating muscle mass. Inadequate protein at meals can negatively affect the stimulation of muscle protein synthesis throughout the day.

 

    The distribution of daily protein intake in individuals is typically the lowest at breakfast and skewed toward dinner. Skewed protein intake patterns and inadequate protein intake at breakfast were reported to be negative factors for muscle maintenance.

 

    A group of scientists from Japan examined whether a protein-enriched meal at breakfast is more effective for muscle synthesis compared with the typical skewed protein intake pattern. They recruited 26 healthy young men who were randomly assigned to two study groups with different protein consumption patterns: “high breakfast” group and “low breakfast” group. The “high breakfast” group (n=12) consumed evenly distributed protein meals throughout the day with protein-enriched breakfast (0.33 g/kg body weight), lunch (0.46 g/kg body weight) and dinner (0.48 g/kg body weight) with an adequate overall daily protein intake (1.30 g/kg body weight/day).

 

    The “low breakfast” group (n = 14) consumed low protein breakfast (0.12 g /kg body weight), same protein content lunch as the other group (0.45 g/kg body weight) and higher protein containing dinner (0.83 g/kg body weight) yielded the same daily protein intake as in the “high breakfast” group.

 

    The study participants performed supervised resistance training 3 times per week. Their body mass including muscle mass was compared at the beginning of the study and at the end of the 12-week study.

 

    The muscle mass at baseline did not differ between the “high breakfast” (52.4 ± 1.3 kg) and “low breakfast” (53.4 ± 1.2 kg) groups. After the 12-week intervention, increases in muscle mass were significant in both groups, with that in the  “high breakfast” group (2.5 ± 0.3 kg) tending to be greater than that in the “low breakfast”  group (1.8 ± 0.3 kg) (P = 0.06). Even though it did not reach the statistical significance of P < 0.05, P = 0.06 was very close to becoming significantly different between the muscle gains in the two groups.

 

    These results may be useful to various population groups:

   

    1). For people who want to do resistance training for muscle gains, consuming a protein-enriched meal at breakfast and less protein at dinner while achieving an adequate overall protein intake can be more effective than consuming more protein at dinner.

 

    2). For people who have dietary habits such as skipping breakfast, having inadequate protein at breakfast, and consuming too much protein at dinner, the inadequate protein intake or skewed protein consumption patterns may lead to reduced muscle mass. This may be especially important to the elderly who are losing muscles during aging.

 

Reference:

Jun Yasuda, Toshiki Tomita, Takuma Arimitsu, Satoshi Fujita. Evenly Distributed Protein Intake over 3 Meals Augments Resistance Exercise–Induced Muscle Hypertrophy in Healthy Young Men. The Journal of Nutrition, Volume 150, Issue 7, July 2020, Pages 1845–1851. https://doi.org/10.1093/jn/nxaa101