View

The Study

Association between usual protein intake and muscle function in older U.S. adults: a target-trial emulation using NHANES 2011–2018

In simple terms

This study looked at whether people who eat more protein tend to have better muscle function, but it only checked everyone once — like taking a snapshot. So we can't tell if eating more protein made them stronger, or if stronger people just ate more protein because they could move better.

44%

Analysis score

44/ 44

Maximum 44 for a cross-sectional study.

Where the score came from

Reporting0
Methodology25
Publication100
Statistical77
Study type (basis of the score)
Cross-Sectional Study
Level 4 - Case series
What’s the bottom line?

This study looked at whether older adults who eat more protein over time have less trouble walking or climbing stairs.

Where does this study sit?

Reviews of RCTs (Meta-analyses)

Max 100

Randomized Trials

Max 90

Reviews of Cohort Studies

Max 85

Cohort Studies

Max 72

Reviews of Case-Control Studies

Max 63

Case-Control Studies

Max 58

Cross-Sectional & Case Series

Max 50

Expert Opinion

Max 5
StrongerWeaker
Cross-Sectional & Case Series
Level 4
44

44 / 100

Quality score

Snapshots of a population at a single point in time, or descriptions of small groups. Can identify correlations and prevalence, but cannot determine cause and effect.

Cannot establish causation

Save studies & get personalized insights

Create a free account to save this study, track new evidence as it comes in, and get breakdowns of studies in the topics you care about.

Key takeaways

Summary

Based on the study abstract and findings.

  1. 1Yes — if you're over 60 and eating less than 1 gram of protein per kg of body weight, you might be at higher risk of mobility problems, and increasing intake to around 1.0–1.1 g/kg could help.
  2. 2People who ate about 1.0–1.1 grams of protein per kg of body weight had the biggest drop in walking trouble.
  3. 3Those eating less than 0.8 g/kg had the most trouble; those eating more than 1.2 g/kg didn’t get much more benefit.
  4. 4On average, older adults ate only 0.93 g/kg.

Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data

Publication

Journal

Journal of the International Society of Sports Nutrition

Year

2026

Authors

Yang Ling, Mingxuan Hou, Muhammad Riaz, N. Rahman

Open Access
Analysis v5
Fit Body Science verdict — we translate health studies into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.