Comparison of protein requirements based on the nitrogen balance and indicator amino acid oxidation methods: an umbrella review and meta-analysis
Study Details
This new meta-analysis compiled data from 60 studies (963 participants) to establish the differences between two methods of estimating protein requirements 🔍
1️⃣ Nitrogen Balance (NB)
2️⃣ Indicator amino acid oxidation (IAAO)
The NB method estimates protein needs by comparing nitrogen intake from dietary protein with nitrogen losses in urine and other routes 📈📉
The IAAO method estimates protein needs by measuring oxidation of a labeled amino acid, which decreases when dietary protein intake is sufficient 🧬
Here are the key findings ⬇️
Key Findings
🙋♂️ In non-athletes, protein requirements were significantly higher by 36% with IAAO vs NB
(0.88 g/kg/day vs 0.64 g/kg/day)
🏋️ In athletes, protein requirements were significantly higher by 27% with IAAO vs NB
(1.61 g/kg/day vs 1.27 g/kg/day)
In non-athletes, IAAO values remained significantly higher than NB values across age and sex subgroups 📈
The IAAO is a most recent method and regarded as most accurate, and on average suggest a 30% greater protein need vs NB 🔬
Conclusion
The current best evidence suggests that athletes need 1.61 g/kg/day protein ✅
Higher daily needs may be required in specific scenarios (e.g. weight loss, high training volumes)‼️
Reference
https://pubmed.ncbi.nlm.nih.gov/40914512/
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