Randomised controlled trialindependent cross-checkabstract checked★ key study I-WHT-116 in-depth review

Refined wheat raised liver fat compared with whole-grain wheat

A 12-wk whole-grain wheat intervention protects against hepatic fat: the Graandioos study, a randomized trial in overweight subjects.

Overview

Schutte S et al.. Am J Clin Nutr 2018 · PMID 30541093 · DOI 10.1093/ajcn/nqy204

In 50 overweight adults, 12 weeks of refined wheat products increased liver fat by 49% relative to whole-grain wheat.

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

Study explained simply

What did the researchers want to find out?: Wheat type and liver fat.
How was the study done?: Double-blind RCT.
How many people, animals or samples were studied?: 50 adults.
What was actually found?: Liver fat rose with refined wheat.
How large was the observed effect?: +49.1% relative.
What do the results mean in everyday life?: Choosing whole-grain wheat may protect the liver.
What are the study's limitations?: Small, short.
What does it say about Elawady's specific claim?: Supports a link between refined flour and liver fat.
Do the results apply to Germany and Europe?: High.
What can explicitly not be concluded from this study?: Cannot show that white flour causes fatty liver disease.

Authors: Schutte S et al.
Journal: Am J Clin Nutr
Year: 2018
Identifier: PMID 30541093 DOI 10.1093/ajcn/nqy204
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

Does whole-grain wheat vs refined wheat affect liver fat?

Study design: Randomised controlled trial – Double-blind randomised parallel trial (Graandioos study)
Population: Overweight men and postmenopausal women aged 45-70
Country: not stated in abstract
Period: not stated in abstract
Sample size: 50
Inclusion and exclusion criteria: Overweight, 45-70 years

Exposure / intervention: Whole-grain wheat products 98 g/day for 12 weeks
Comparator: Refined wheat products 98 g/day
Endpoints: Intrahepatic triglycerides (1H-MRS), fat distribution, microbiota, plasma markers
Statistical methods: Between-group comparisons

Results: Intrahepatic triglycerides increased by 49.1% in the refined wheat group compared with the whole-grain wheat group (P=0.033). Fasting lipids and insulin unchanged. Microbiota diversity decreased with refined wheat (P=0.010). Postprandial triglycerides higher with whole-grain wheat (P=0.020).
Absolute risks: not reported
Authors' conclusion: A 12-week refined wheat intervention increases liver fat; 98 g/day whole-grain wheat prevents this increase.

Relative difference in liver fat; absolute values not in abstract, so recalculation impossible.

First randomised evidence that refined wheat (vs whole-grain wheat) increases liver fat.

I-WHT-05 (observational null).

High.

Small but direct RCT support.

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

Replication; clinical NAFLD outcomes.