When I first started to learn about nutrition, I found a lot of conflicting information about protein. The USFDA recommendations were low. Advice 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 over the years, 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 in males resulting in a recommendation of 1.6 grams / 1 kg of body weight, which is .73 grams / 1 lb body weight. For women at 33% body fat, this would be 1.4 grams / 1 kg of body weight, which is .63 / 1 lb body weight.
• Younger folks who are actively training, or older adults not actively training should consume 1.2g/kg, or .54g/lb lean body weight.
• Younger folks who are not actively training should avoid eating a caloric surplus (duh) and keep protein to around .8g/kg to minimize cancer risk.
• Minimum effective dose in adults is around 20-25 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. In rare cases, larger amounts of protein can be consumed at one time if it is slowly metabolized such as casein proteins.
• 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.

The absorption rate of protein affects the optimal amount of protein consumed at one time. See article about protein anabolic responses.

There can be downsides of too much protein.

Other 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 which is reflected in his longevity diet
  • .8g protein / 1kg body weight under 65. Over 65 more, I believe the target is 1.2g / kg
• FoundMyFitness :  97 The Science of Protein by Rhonda Patrick.
  • Protein needs vary based on individual goals, such as building muscle, maintaining it, or improving body composition. Calculating protein intake based on lean body mass or an adjusted ideal body weight is preferred to avoid unrealistic targets for individuals with higher body fat percentages. While the Recommended Dietary Allowance (RDA) for protein is 0.8 grams per kilogram of body weight per day, this amount is widely considered inadequate for optimal health. The RDA is based on nitrogen balance studies, which have significant limitations.
  • Stable isotope studies suggest that the optimal protein intake is closer to 1.2 to 1.6 grams per kilogram of body weight daily (0.54 to 0.72 grams per pound). Evidence supports this higher intake, particularly in older adults, where consuming at least 1.2g/kg per day can prevent lean mass loss and reduce frailty by 30%. For those engaged in resistance training, 1.6g/kg per day has been shown to maximize gains in lean mass, with a 27% increase compared to a 1.2g/kg intake.

I asked chat-gpt (4o model) optimal protein for building and maintaining muscle. Here was it’s response:

Protein Needs Based on Lean Body Mass (LBM)

Category	Protein Intake (g per kg LBM)	Protein Intake (g per lb LBM)
Under 25, Actively Training (Strength & Resistance)	2.0 – 2.7 g/kg	0.9 – 1.2 g/lb
Over 60, Actively Strength Training	2.2 – 3.0 g/kg	1.0 – 1.4 g/lb
Age 30, Active but Not Strength Training	1.5 – 2.0 g/kg	0.7 – 0.9 g/lb
Age 65, Active but Not Strength Training	1.8 – 2.3 g/kg	0.8 – 1.0 g/lb

Other Considerations

• Strength trainees (young and old) need more due to high muscle turnover and the need to maximize muscle protein synthesis.
• Older adults (especially over 60) require more protein per unit of LBM due to anabolic resistance.
• Non-strength training active individuals need less protein than resistance trainers but still require adequate amounts for recovery and lean mass preservation.
• Protein Distribution: Spread intake across 3-5 meals per day, ideally 20-40g per meal, to maximize muscle protein synthesis.
• Leucine Content: Include high-leucine sources (e.g., whey protein, eggs, lean meats) to enhance muscle-building signals.
• Strength Training Matters: Resistance training significantly enhances the muscle-preserving effects of protein, especially in older adults.