Skip to content

Cohort studycited by the Tayebat archiveabstract only checked A-WHT-15 standard review

GI, fibre and diabetes in young women

Glycemic index, glycemic load, and dietary fiber intake and incidence of type 2 diabetes in younger and middle-aged women.

Overview

Schulze MB et al.. Am J Clin Nutr 2004 · PMID 15277155 · DOI 10.1093/ajcn/80.2.348

High GI linked to 59% higher risk; cereal fibre to 36% lower risk.

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

Original publication

Plain-language summary

Study explained simply

What did the researchers want to find out?: GI/fibre and diabetes
How was the study done?: Cohort
How many people, animals or samples were studied?: 91,249
What was actually found?: GI up, fibre down
How large was the observed effect?: RR 1.59/0.64
What do the results mean in everyday life?: Carb quality matters
What are the study's limitations?: Observational
What does it say about Elawady's specific claim?: Indirect
Do the results apply to Germany and Europe?: Moderate
What can explicitly not be concluded from this study?: Cause

Scientific in-depth review

1. Full reference

Authors: Schulze MB, Liu S, Rimm EB, Manson JE, Willett WC, Hu FB
Journal: Am J Clin Nutr
Year: 2004
Identifier: PMID 15277155 DOI 10.1093/ajcn/80.2.348
Verification: verified – PubMed E-utilities efetch, 2026-10-25
Retracted: no
Corrections: none
Extent checked: abstract only
Conflicts of interest and funding: None stated; NCI grant.

2. Research question

GI, GL, fibre and T2D

3. Study design and population

Study design: Cohort study – Prospective cohort (NHS II)
Population: 91,249 women
Country: USA
Period: 8 y
Sample size: 91,249; 741 cases

4. Methods and endpoints

Exposure / intervention: GI, GL, cereal fibre
Comparator: Q1
Endpoints: T2D
Statistical methods: Multivariable RR

5. Actual results

Results: GI Q5 RR 1.59 (1.21-2.10); cereal fibre Q5 RR 0.64 (0.48-0.86); GL Q5 RR 1.33 (0.92-1.91; not significant).
Absolute risks: 741 cases in 716,300 person-years
Authors' conclusion: Diet high in rapidly absorbed carbohydrates and low in cereal fibre associated with T2D.

6. Strengths

Large

7. Weaknesses

Observational; GL null

8. Risk of bias

Orienting tool: ROBINS-E
Type of assessment: simplified assessment (abstract only)
Full formal assessment: no
Overall risk of bias: some concerns

9. Assessment of the statistical interpretation

10. Relevance to the specific claim

Supports C-WHT-05.

11. Independent contrary findings

12. Transferability to Germany and Europe

Moderate.

13. Overall methodological judgement

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	moderate
Risk of bias	some concerns
Precision of results	moderate
Directness	indirect
Reproducibility	replicated
Consistency with the overall evidence	consistent
Regional transferability	moderate
Adequacy of the interpretation (by the archive)	not applicable

14. Open questions

15. Linked fact checks

Diets rich in rapidly absorbed carbohydrates (high glycaemic index/load) and poor in cereal fibre raise type 2 diabetes risk by about 50%, and each 10 g/day of cereal fibre lowers risk by 25%; refined flour therefore promotes diabetes. – Studies supporting the claim

Use by the Tayebat archive

Note: according to the archive, the studies were compiled by the archive operators. Whether Dr. Elawady himself cited this study is not established.

What the archive says about the study: Listed in bibliography only.
E. Is this derivation scientifically justified?: Indirect support; GL not significant.
Adequacy of the interpretation (by the archive): not applicable