Phillips, Chevalier, & Leidy (2016): https://pubmed.ncbi.nlm.nih.go... Fulgoni (2008): https://pmc.ncbi.nlm.nih.gov/a... (Note: Abstract text overview is indexed under PMC5347101)
The average amount of protein eaten:
1.07 g / kg / day for men.
0.89 g/kg / day for women.
Average: 0.89 g / kg / day
The Scientific Case for a Higher RDA
The traditional protein Recommended Dietary Allowance (RDA) of 0.8 g/kg/day is increasingly viewed by nutritional scientists as an outdated metric. The core evidence for raising this baseline includes:
Flawed Methodology: The 0.8 g/kg standard was built on nitrogen balance studies, which only measure the absolute minimum amount of protein required to prevent lean tissue wasting and clinical deficiency.
Modern Metabolic Tracing: Utilizing the Indicator Amino Acid Oxidation (IAAO) method—which tracks breath markers to find when the body's amino acid pathways are genuinely saturated—studies show that metabolic requirements for healthy, sedentary young adults plateau closer to 1.2 g/kg/day.
Functional Outcomes: Massive clinical reviews show that a range of 1.2 to 1.6 g/kg/day is required to optimize actual health outcomes, including triggering satiety hormones, managing weight, and preserving skeletal muscle mass.
Consumption Patterns vs. the Optimal Range
When evaluated against how people actually eat, the current 0.8 g/kg/day guideline creates a false sense of dietary adequacy.
[Deficiency Minimum] 0.8 g/kg/day (Current RDA)
[Actual Intake] 0.89 g/kg/day (Average American Consumption)
[Optimal Function] 1.2 – 1.6 g/kg/day (Modern Scientific Consensus)
Data from the National Health and Nutrition Examination Survey (NHANES) shows that the average American adult consumes roughly 0.89 g/kg/day. Because this number clears the official 0.8 g/kg baseline, public health dashboards register the population as "adequate" in protein intake.
However, because 0.89 g/kg/day sits completely below the 1.2 to 1.6 g/kg/day optimal range, the typical consumption pattern leaves the majority of Americans in a functional deficit—meeting the bare survival minimum while missing the threshold needed for metabolic health and muscle preservation.
In addition men have more proportional muscle mass and higher metabolisms.
A back of the envelope calculation:
1. Variables (Percentage Beyond Average)
Metabolism Advantage: +3.75% (Multiplier: 1.0375)
Lean Mass Advantage: +8.75% (Multiplier: 1.0875)
2. Compounding the Advantages
1.0375 × 1.0875 = 1.12828125 (+12.83% Total Scaling Factor)
3. Applying the Scaling Factor to Baselines
At a Survival Baseline (0.8 g/kg average):
0.80 g/kg × 1.1283 = 0.9026 g/kg (Minimum for Men)
At an Optimal Baseline (1.3 g/kg average):
1.30 g/kg × 1.1283 = 1.467 g/kg (Optimal for Men)
This supports the contention that broadly speaking we need more not less protein ergo meat. Especially men.