Cohort studyindependent cross-checkabstract checked I-EGG-120 standard review

Chinese survey: very high egg intake linked to diabetes

Egg, cholesterol and protein intake and incident type 2 diabetes mellitus: Results of repeated measurements from a prospective cohort study.

Overview

Yuan S et al.. Clin Nutr 2021 · PMID 33593662 · DOI 10.1016/j.clnu.2021.01.041

People eating 3+ eggs a day reported diabetes more often (OR 3.76), but the study had few cases.

Does the study support the specific claim? Partly · Methodological quality: low

Study explained simply

What did the researchers want to find out?: Study eggs and diabetes in China.
How was the study done?: Cohort with repeated surveys.
How many people, animals or samples were studied?: 7,312 adults; 209 cases.
What was actually found?: Association only at very high intake.
How large was the observed effect?: OR 3.76 (2.05-6.90).
What do the results mean in everyday life?: Eating three or more eggs daily is unusual; this does not show that normal intake is risky.
What are the study's limitations?: Self-reported diabetes; few cases.
What does it say about Elawady's specific claim?: Weak, partial support.
Do the results apply to Germany and Europe?: Low.
What can explicitly not be concluded from this study?: It cannot prove causation.

Authors: Yuan S et al.
Journal: Clin Nutr
Year: 2021
Identifier: PMID 33593662 DOI 10.1016/j.clnu.2021.01.041
Verification: verified – PubMed efetch 2026-10-26; Crossref works API 2026-10-26
Retracted: no
Corrections: none
Extent checked: abstract only
Conflicts of interest and funding: not stated in abstract

Are egg, cholesterol and protein intakes associated with type 2 diabetes in Chinese adults?

Study design: Cohort study – Prospective cohort with repeated dietary measurements (China Health and Nutrition Survey 2004-2011)
Population: Chinese adults (7,312 in 2004 wave)
Country: China
Period: 2004-2011 (mean follow-up 5.8 years)
Sample size: 7,312 at baseline; 209 incident cases
Inclusion and exclusion criteria: not detailed in abstract

Results: Highest vs lowest protein quartile OR 2.38 (1.43-3.98); >=3 eggs/day vs none OR 3.76 (2.05-6.90); cholesterol intake not associated.
Absolute risks: not reported
Authors' conclusion: A high intake of egg, but not dietary cholesterol, was associated with type 2 diabetes; warrants further investigation.

Orienting tool: ROBINS-E
Type of assessment: simplified assessment (abstract only)
Full formal assessment: no
Overall risk of bias: high
Rationale: Self-reported outcome, few events, unusual exposure categorisation.

Large OR with wide CI from few events; not comparable with meta-analytic estimates.

A non-US study supporting an egg-diabetes association, but only at very high intake and with weak methods.

Asian pooled RR 0.82 (I-EGG-08).

Low.

Weak support; listed for fairness.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	low
Risk of bias	high
Precision of results	low
Directness	direct
Reproducibility	not replicated
Consistency with the overall evidence	inconsistent
Regional transferability	moderate
Adequacy of the interpretation (by the archive)	not applicable

Replication with clinical diagnosis.