Source of Recommendations

# Sources of Recommendations

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Last updated: April 17, 2026

PRTN AI provides personalized protein intake recommendations based on body weight, training goal, and (if specified) weight-loss medication. This document describes the scientific sources that underpin our recommendations.

**Important:** PRTN AI does not provide medical advice. All recommendations are for general informational purposes only. Please consult a physician or qualified dietitian before making significant dietary changes, especially if you have pre-existing health conditions.

## Our Recommendation Ranges

| Training Goal | Multiplier |
|---|---|
| Muscle gain | 2.0 g/kg/day |
| Maintain | 1.6 g/kg/day |
| Weight loss | 1.8 g/kg/day |
| Performance | 1.8 g/kg/day |
| GLP-1 medication or bariatric surgery | additional +0.2 g/kg/day |

Results are rounded to the nearest 5 g.

## Scientific Sources

### Baseline and Minimum Requirements

1. Institute of Medicine. *Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids.* Washington, DC: The National Academies Press; 2005. DOI: [10.17226/10490](https://doi.org/10.17226/10490)

### Protein and Exercise (Position Stands)

2. Jaeger R et al. International Society of Sports Nutrition Position Stand: protein and exercise. *JISSN.* 2017;14:20. DOI: [10.1186/s12970-017-0177-8](https://doi.org/10.1186/s12970-017-0177-8). PMID: 28642676

3. Thomas DT, Erdman KA, Burke LM. ACSM Joint Position Statement: Nutrition and Athletic Performance. *Med Sci Sports Exerc.* 2016;48(3):543-568. DOI: [10.1249/MSS.0000000000000852](https://doi.org/10.1249/MSS.0000000000000852). PMID: 26891166

### Muscle Growth: Optimal Dosing

4. Morton RW et al. Protein supplementation and resistance training-induced gains in muscle mass and strength. *Br J Sports Med.* 2018;52(6):376-384. DOI: [10.1136/bjsports-2017-097608](https://doi.org/10.1136/bjsports-2017-097608). PMID: 28698222

5. Phillips SM, Van Loon LJC. Dietary protein for athletes: from requirements to optimum adaptation. *J Sports Sci.* 2011;29(sup1):S29-S38. DOI: [10.1080/02640414.2011.619204](https://doi.org/10.1080/02640414.2011.619204). PMID: 22150425

### Protein During Caloric Deficit and Weight Loss

6. Helms ER et al. Dietary protein during caloric restriction in resistance trained lean athletes. *Int J Sport Nutr Exerc Metab.* 2014;24(2):127-138. DOI: [10.1123/ijsnem.2013-0054](https://doi.org/10.1123/ijsnem.2013-0054). PMID: 24092765

7. Mettler S, Mitchell N, Tipton KD. Increased protein intake reduces lean body mass loss during weight loss in athletes. *Med Sci Sports Exerc.* 2010;42(2):326-337. DOI: [10.1249/MSS.0b013e3181b2ef8e](https://doi.org/10.1249/MSS.0b013e3181b2ef8e). PMID: 19927027

### GLP-1 Medication and Bariatric Surgery

8. Nunn E, Jaiswal N, Graeff J. GLP-1 receptor agonists and skeletal muscle: a dual-edged sword? *Nat Rev Endocrinol.* 2024. DOI: [10.1038/s41574-024-01072-1](https://doi.org/10.1038/s41574-024-01072-1)

9. Mechanick JI et al. AACE/TOS/ASMBS Guidelines for bariatric surgery patient nutrition. *Obesity.* 2013;21(S1):S1-S27. DOI: [10.1002/oby.20461](https://doi.org/10.1002/oby.20461). PMID: 23529939

### Safety of High Protein Intake

10. Antonio J et al. A high protein diet has no harmful effects: a one-year crossover study. *J Nutr Metab.* 2016;2016:9104792. DOI: [10.1155/2016/9104792](https://doi.org/10.1155/2016/9104792). PMID: 27807480

### Protein Needs in Older Adults

11. Bauer J et al. PROT-AGE Study Group: optimal dietary protein intake in older people. *JAMDA.* 2013;14(8):542-559. DOI: [10.1016/j.jamda.2013.05.021](https://doi.org/10.1016/j.jamda.2013.05.021). PMID: 23867520

### Protein Distribution

12. Schoenfeld BJ, Aragon AA. How much protein can the body use in a single meal for muscle-building? *JISSN.* 2018;15:10. DOI: [10.1186/s12970-018-0215-1](https://doi.org/10.1186/s12970-018-0215-1). PMID: 29497353