Quick Summary

• Protein is essential for nearly every function in the body — from cellular activity to building muscle, bones, and neurotransmitters.
• As we age (especially post-40), we experience anabolic resistance, making it harder to build and maintain muscle.
• To counteract this, researchers (like Dr. Donald Layman) recommend:
  • Resistance training
  • Higher protein intake: ~1 gram of protein per pound of ideal body weight per day.
• Fears around high protein intake stem from outdated or flawed studies (e.g., on worms or people with kidney disease) and decades of biased nutrition science.
• Ultimately, everyone is biochemically unique — try increasing protein and see how it affects your energy, mood, pain, and focus.

Protein is absolutely critical to our overall health and vitality.

Why?  We need proteins (and their constituent amino acids) for:

• most of our cellular functions!
• the structure & regulation of all tissues and organs
• making neurotransmitters
• building bones, connective tissue, and of course MUSCLE

In a nutshell:  We’re made of proteins, so we need protein to build and maintain all our parts. 

Protein for Muscle Maintenance

We previously talked about the fact that healthy (and active!) muscle tissue tracks with improvements in every aspect of our health.

Unfortunately, the farther we get past 40, the more likely we are to become “anabolic resistant,” which means it becomes more difficult to build and maintain muscle.  That’s why the condition called sarcopenia is commonly defined as muscle loss that occurs with aging.  It has long been assumed that as we age, we will inevitably lose much of our muscle.

However, a group of researchers led by Dr. Donald K. Layman (professor Emeritus in Nutrition at the University of Illinois) have documented a proven formula to combat anabolic resistance:  appropriate resistance exercise supported by a relatively high protein intake:

One gram of protein per day, per pound of bodyweight that you’d like to maintain.

So decide what your “ideal body weight” is, bearing in mind that if you’ve never had much muscle, that number might be higher than your current weight.  Whatever that number is (in pounds) is your target intake of grams of protein per day.  Simply put, if your target weight is 140 pounds, you’re looking for 140 grams of protein each day.

Wow, how do I eat that much???

This is probably significantly more protein than you’re currently getting.  How to get there?

1. First things first:  how much protein are you generally getting now?  Choose a nutrition website or app to look up foods you commonly eat and find the protein content.  A food scale is also helpful, to know for sure what you’re getting.  You won’t have to weigh and count forever!  After a while, you’ll have a sense of how to get to your protein goal, and you won’t need those tools any more.
2. Can you slightly increase the portions of the protein foods you’re already eating?  For muscle protein synthesis, it’s recommended to try to get ~40 grams of protein in the first and last meals of the day, so nudge those up as much as you can.
3. It’ll still be tricky to eat that much protein, so many folks use a protein shake to get across the finish line.  Whey Protein Isolate is a good one for muscle-building (and having Isolate, instead of Concentrate, removes the lactose & casein which are the elements of dairy that most commonly cause problems).

Then why do some people say to limit protein intake?

There are many ways in which nutrition science went off the rails starting in the 1940’s.  Here are just a few reasons relevant to protein:

1. A great deal of what we think we know about protein intake and longevity is based on experiments on C. elegans, a one-millimeter long worm that goes into a dormant state due to lack of food, and therefore lives longer the more that food is made scarce.  Humans do not enter a dormant state, due to food scarcity or at any other time, not to mention the fact that we are much more complex organisms than millimeter-sized worms, so it’s nonsensical to extrapolate from C. elegans to us, and yet that is where much of the data comes from.  There are similar problems that arise in using various species of mice to gain insight into human nutrition, which is also common.
2. These less-than-ideal experimental animals are used because it is really difficult and expensive to run a long-term experiment on humans!  Because of this, the first decades of nutritional research were based on epidemiological surveys, meaning questionnaires that ask people to recall their eating habits over a period of time.  For example:  How many servings of chicken have you had per week, on average, over the past year?  This type of “research”, along with hefty doses of politics and ideology, steered nutrition research and recommendations in a direction that have not been great for human health.  Just look around; you can see that’s true.  If you still carry some phobia of eating meat and fat, please consider reading The Big Fat Surprise by Nina Teicholz.  (spoiler: the “French paradox” is not a paradox at all!)
3. Badly-damaged or diseased kidneys can have difficulty processing protein, but there is no evidence that healthy kidneys do.  Yet due to the effect in this very specific (and unwell) population, recommendations were made for the entire population.  There are many such examples of inappropriate extrapolations throughout nutrition science!

You are the expert

Ultimately, you are biochemically unique, so only you can know the best way of eating for YOU.  But, if you feel that you could have more energy, less pain, a better mood and a clearer mind, give protein a try!  Even if you can’t get to the “1 gram per pound” number – just see how high you can comfortably take your protein, and then see how you feel.

1. Layman, Donald K., et al. “Defining meal requirements for protein to optimize metabolic roles of amino acids.” The American Journal of Clinical Nutrition, vol. 101, no. 6, 2015, pp. 1330S–1338S.
   — This source provides foundational research on protein intake for muscle maintenance, especially in aging populations.
2. Teicholz, Nina. The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet. Simon & Schuster, 2014.
   — Cited as a resource challenging outdated dietary guidelines and supporting the health benefits of traditionally demonized foods like meat and fat.
3. Fontana, Luigi, and Linda Partridge. “Promoting health and longevity through diet: from model organisms to humans.” Cell, vol. 161, no. 1, 2015, pp. 106–118.
   — Discusses limitations in extrapolating longevity and nutrition research from organisms like C. elegans and mice to humans.