When I first started to learn about nutrition, I found a lot of conflicting information about protein. The USFDA recommendations were low. Advise to body builders was high. There seemed to be differing views about optimal timing, the minimum effective dose, maximum effective dose, etc. Yesterday I listed to podcast #224 ‒ Dietary protein: amount needed, ideal timing, quality, and more | Don Layman, Ph.D. – Peter Attia. The discussion between Attia and Don Layman crystalized everything I had read, and a quick email with Don confirmed my understand.

TL;DR

• Older adults who are actively training should consume 2 grams / 1 kg of LEAN body weight. People generally don’t know their lean body weight, so the most common recommendations assume 20% body fat resulting in a recommendation of 1.6 grams / 1 kg of body weight, which is .73 grams / 1 lb body weight.
• Younger folks who are actively training, or older adults not actively training should consume 1.2g/kg
• Younger folks who are not actively training should avoid eating a caloric surplus (duh) and keep protein down to around .8g/kg to minimize cancer risk.
• Minimum effective dose in adults is around 25 grams / meal. Less than that you are you feeding other systems, but not triggering muscle synthesis which you really want!!
• Maximum effective dose for muscle synthesis is around 50 grams. Above that, it’s turned into fuel for organs or saved as fat. Larger amounts of protein can be consumed at one time if it is slowly metabolized
• In the first 3 months of new training, get protein within 2 hours. Otherwise timing doesn’t matter
• Make sure your first, and last meals have adequate protein. Ideally approach the maximum dose in your first meal.

Background

Protein is needed by the body. The body needs around 300 grams of “new” protein / day. Most of this comes by way of recycling within the body. As we age, the recycling becomes less effective requiring us to consume more protein.

There are a wide variety of proteins which our body produces from over 20 different amino acids. There are nine essential amino acids that our body can’t produce. We need to consume them. The protein we eat gets broken down and then used.

It is useful to think about dietary protein as a vitamin containing essential amino acids. The % of macro-nutrients in our diet from protein isn’t so important. What’s critical is that we are consuming enough (e.g. it’s an absolute number).

For adults (>25) it’s critical to consume enough essential amino acids, which we typically get through the consumption of protein, to drive muscle synthesis. Protein (for this purpose) is not so important in younger folks whose muscle synthetic is driven by hormones.

There can be downsides of too much protein.

Useful References

• Evidence-Based Recommendations for Optimal Dietary Protein Intake in Older People: A Position Paper From the PROT-AGE Study Group
  • To maintain and regain muscle, older people need more dietary protein than do younger people; older people should consume an average daily intake in the range of 1.0 to 1.2 g/kg
  • The per-meal anabolic threshold of dietary protein/amino acid intake is higher in older individuals (ie, 25 to 30 g protein per meal, containing about 2.5 to 2.8 g leucine) in comparison with young adults.
• A Critical Examination of Dietary Protein Requirements, Benefits, and Excesses in Athletes
  • 1.2–1.6 g protein / kg
• The myth of 1 g / 1 lb: Optimal protein intake for bodybuilders
  • 1.8g / kg (.82g / lb)
• Protein – Which is Best?
  • Bio-availability and quality of protein sources
• Peter Attia’s Recommendations about Protein
  • 1.2-2.2 g protein/kg body weight. This seems high to me.
• Formulas For Effecting Body Composition Change!
  • protein 1 gram / lb lean, 2 gm carb /weight, .2 g fat / lb
• Dietary protein for athletes: From requirements to optimum adaptation]]25 grams optimal dose
  • Ratio of macro nutrients
• Dietary protein recommendations and the prevention ofsarcopenia
  • Meals should be 30g of protein in older people
• A second look at protein quantity after exercise | Examine.com]
  • 40g whey more impact than 20g whey post exercise
• Protein Intake – How Much Protein Should You Eat Per Day?
• Forthcoming studies by Valter Longo.
  • .8g protein / 1kg body weight under 65. Over 65 more, I believe the target is 1.2g / kg
  • 1.2-2.2 g protein/kg body weight