Oftentimes when I am speaking with a client of mine who is interested in improving their diet, one of the first things I recommend they do is track their calories. Not only that, but the amount of protein they ingest, specifically. More often than not, individuals can benefit from ingesting far more protein than they are currently consuming.
The standard daily dietary guidelines set in Canada and the United States at 0.8g/kg really should be considered a bare minimum. General recommendations for active individuals fall into the 1.5-2.2g/kg bodyweight (0.68-1g/lb.). So a 180lb. individual, should aim closer to 123-180g of protein per day versus just 65g as the bare minimum.
According to a recent study (Protein Ingestion to Stimulate Myofibrillar Protein Synthesis Requires Greater Relative Protein Intakes in Healthy Older Versus Younger Men), aging men should aim for at least that.
Our data demonstrate, for the first time, that the relative quantity of ingested protein required to maxi- mize MPS is greater in older as compared with younger men. Thus, presuming a maximal MPS response at each of the traditional three meals of a day (ie, breakfast, lunch, and dinner) would help maintain muscle mass with age, our data lend some support to recent recommendations based on a similar premise of maximizing MPS that optimal protein intakes for older persons could be higher than the current U.S.-Canadian recommended dietary allowance of 0.8 g/ kg/d.
There are some very interesting thoughts and conclusions that can stem from this study.
First, it is important to note that although increased amounts of protein are generally recommended for active individuals, the importance of increased protein ingestion seems to be magnified with age. The age gap is pretty substantial in this study, however (mean age of 22 - ‘younger’, vs. 71 - ‘older’), but the reliance on greater amounts of dietary protein should still be taken into consideration as we age. Our reduced sensitivity to ingested protein in order to trigger muscle protein synthesis should not be discounted.
Regardless of the bare minimum when it comes to recommended dietary intake of protein, it seems as though the younger the individual, the more forgiving their bodies are. What I mean by that, is that the body seems to require less ingested protein in order to stimulate muscle protein synthesis, therefore, not only slowing or reversing the effects of myofibrillar catabolism, but can increase anabolism as well.
There was mention in this study about the amino acid leucine, specifically its ability to increase muscle protein synthesis. Leucine - a common amino acid found in beef, peanuts, chicken, salmon, almonds, eggs, etc., is known to activate mTOR, a regulator of cell growth. Not only should individuals reach for more protein as they age, but it is certainly recommended that sources of leucine be given preferential treatment when it comes to the dietary choices we make.
Exercise and resistance training also should not be discounted here. Although increased rates of protein can slow down the effects of muscular catabolism as we age, the stimulus (resistance training) for our muscle cells to proliferate is indeed extremely important for our bodies to not only maintain strength, but to reduce and even reverse muscle loss associated with aging.
It should also be noted that this study was completed comparing younger versus older men. Although it could be speculated that a similar outcome would be found when comparing young versus older women, one can not jump to that conclusion at this time. I will, however, still continue to recommend both men and women use protein as a cornerstone to their diets and put more reliance on what they eat to hit their protein goals and fill in the missing calories with healthy carbohydrate and fat sources, regardless of age or activity level.
Just please do me a favour, don’t turn into one of these guys (video below)…
Tyler Robbins B.Sc. CSCS
Director of Fitness
Head of CrossFit