When bodybuilders and athletes are aiming to build muscle mass it’s not uncommon for them to eat every two to three hours and up to six times each day. This type of eating schedule has been followed almost religiously for decades and with good reason, it works! However, when something has been done for a long time it doesn’t always mean that it’s necessary. What I’ll aim to do in this article is separate fact from fiction based on the relevant research and give some suggestions about how it can be applied for those who are primarily training for muscle growth.
What the research says
It’s long been believed that consuming protein every few hours throughout the day is optimal for building muscle mass. This is due to the belief that frequent feedings optimise muscle protein accretion by constantly increasing levels of protein synthesis which negates muscle protein breakdown.1,2 A 2013 study by Areta et al. compared the effects of different eating frequencies on protein synthesis. The study had twenty four trained men consume 80 grams of whey protein over a 12 hour period following a weight training session with each participant assigned to one of three feeding schedules (8 x 10 grams every 90 minutes, 4 x 20 grams every 3 hours or 2 x 40 grams every 6 hours). The results showed the schedule that involved 4 x 20 grams of protein consumed every three hours was superior to the other schedules for stimulating protein synthesis.3 While this study shed some light on both protein feeding frequency and protein quantity at each meal for maximising muscle growth, multiple limitations of the study make it difficult to apply this to every day practice. First, the study had participants consume only high quality whey protein without any other macronutrients which is in contrast to real life eating patterns. This is due to the fact that meals containing multiple macronutrients (Protein, carbohydrates and fat together) take longer to digest than when protein is consumed on its own. In addition, the 80 gram dose of protein given to subjects is significantly below the recommended daily protein intake required to maximise muscle mass.
Another study by Mamerow also attempted to compare different protein feeding distributions. Using eight healthy subjects, the study had each participant consume protein during three meals a day over two different eating conditions over two separate 7 day periods. The first condition had subjects consume protein evenly throughout the day while the second condition was skewed so approximately 66% of daily protein intake was consumed at dinner. Unlike the previous study, the daily protein dose was high enough to promote an anabolic response (approx. 1.6 grams per kilo of bodyweight per day). Results concluded that protein synthesis was about 25% greater when protein intake was consumed evenly compared to the skewed condition.4
It should be noted that age is a relevant factor in how much protein should be consumed at each meal and how often consumption should take place. It’s been postulated that ageing negates the responsiveness of muscle to protein consumption. This means that a greater amount of protein is required at each meal to trigger protein synthesis in older people. Studies estimate that for elderly people roughly 40 grams of protein is required at each meal to trigger an anabolic response while young people require just over half this amount.5,6 Arnal et al. showed that elderly women were able to retain more muscle mass when consuming almost 80% of their daily protein intake in a single meal compared to evenly spread meals.7 This doesn’t mean that an uneven distribution of protein consumption is required for older people, rather it indicates that a higher dose of protein is required per meal to stimulate protein synthesis. The same researchers found that there were no significant differences in body composition between evenly spread protein consumption and uneven protein consumption in young women further highlighting that age is a major factor in how much protein is required at each meal to promote anabolism.7 Finally and perhaps most intriguingly, Hellerstein and colleagues and Donald Layman both concluded that the anabolic impact of an individual meal containing protein is likely to last for 5-6 hours based on the rate of amino acid metabolism after a meal. 8,9
Putting it all together
Based on the relevant research it seems that to maximise muscle growth one should aim to consume at least 3 meals spread throughout the day containing enough high quality protein to reach daily protein requirements. (See article on daily protein intake here: (LINK)) In order to promote an anabolic response, elderly people should consume roughly 40 grams of protein per meal while younger people should aim for at least 25 grams at each meal. Seeing that the anabolic impact of a meal containing sufficient protein lasts about 5-6 hours, then in order to maximise muscle growth meals should be spaced apart no longer than this timeframe. As you can now see, it isn’t necessary to conform to the traditional eating schedule of 6 meals a day every 2-3 hours to maximise muscle growth. If this eating frequency is what you prefer and is more practical for you then I am by no means discouraging you from doing this. However, you can rest easy knowing that you’re not going to hamper your progress if other commitments don’t allow you to adhere to this. Obviously, if you’re looking to maximise muscle mass your nutrition must be accompanied by a progressive resistance training program.