How critical is the timing and quantity of protein intake for optimizing muscular health and performance?

Overview

What did they test? The review focused on investigating the relationship between protein intake during breakfast and its effects on muscle mass and strength in adults.
What did they find? The review found that a significant majority (58.8%) of the studies reported an increase in muscle mass associated with higher protein consumption at breakfast.
What does it mean for you? For individuals looking to enhance or maintain muscle mass and strength, incorporating a higher protein intake during breakfast could be beneficial. However, some terms and conditions apply.

What’s the Problem?

In recent years, the role of dietary protein in maintaining muscle health, especially among older adults, has gained significant attention in the scientific community. The scientific community has also attempted to explore the role of protein when it comes to maximizing muscle mass and strength adaptations, with the previous issue of REPS touching on the first study to ever look at whether we can effectively use 100g of protein in one sitting. 

It's been established that consuming enough protein, particularly from high-quality sources, can significantly enhance muscle protein synthesis, which in turn can lead to improved muscle mass, strength, and physical function. However, the current Recommended Daily Allowance (RDA) for protein intake, set at 0.8 grams per kilogram of body weight per day, is thought to be insufficient for many adults with experts now suggest a higher intake of 1.2 grams per kilogram per day to better support muscle maintenance and functionality, especially as one ages. Research indicates that consuming as little as 20-30 grams of protein per meal, or 0.4 grams per kilogram per meal, is associated with increases in skeletal muscle mass and strength in older adults 1, while it was believed that evenly distributing protein intake across meals can optimally stimulate muscle protein synthesis, something that has been somewhat debunked as seen on the previous issue of REPS. 

Protein distribution and muscle protein synthesis aside, there's an observed trend, both in Western and Asian countries, of breakfast being a meal typically low in protein, with daily protein intake unevenly distributed across meals. Although some researchers, including the ones that conducted the study we’re about to review, have argued that consuming a breakfast low in protein can negatively affect muscle protein synthesis which in turn can affect muscle quality, I think that’s not really the issue at hand here.