Increasing the frequency of protein consumption is recommended to stimulate muscle hypertrophy with resistance exercise. Researchers manipulated dietary protein distribution to assess the effect on gains in lean mass during a rugby preseason. 24 developing elite rugby athletes were instructed to consume high biological value protein at their main meals and immediately after resistance exercise while limiting protein intake between meals. To manipulate protein intake frequency, the athletes consumed 3 liquid protein supplements (22 g protein) either with main meals or between meals for 6 weeks. At the end of six weeks, the dietary manipulation successfully altered the protein distribution score (average number of eating occasions containing > 20 g of protein) to 4 to 6 but there was no difference in gains in lean mass between conditions.
There was no clear effect of increasing protein distribution from approximately 4 to 6 eating occasions on changes in lean mass during a rugby preseason. However other dietary factors may have augmented adaptation. So the morale of the story is that you need protein for optimal gains in muscle mass but increasing the amount of protein you consume at each meal is not going to further augment gains in lean muscle mass. There seems to be a ceiling effect with protein consumption, once you have reached an optimal dose of protein saturation in your body, further increases in protein are not going to be beneficial.
MacKenzie-Shalders KL, King NA, Byrne NM, Slater GJ. Increasing Protein Distribution has no Effect on Changes in Lean Mass During a Rugby Preseason. Int J Sport Nutr Exerc Metab. 2015 Jul 1.