Trial reportDiabetologia2018
Fibre supplementation for the prevention of type 2 diabetes and improvement of glucose metabolism: the randomised controlled Optimal Fibre Trial (OptiFiT).
Trial report in Diabetologia, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT01681173 (Investigation of the Effect of Insoluble Dietary Fiber on Carbohydrate and Lipid Metabolism and the Prevention of Diabetes Mellitus Type 2 in Subjects With Impaired Glucose Tolerance), which is not on this map. Cited by 29 papers, 1 of them a synthesis that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Investigation of the Effect of Insoluble Dietary Fiber on Carbohydrate and Lipid Metabolism and the Prevention of Diabetes Mellitus Type 2 in Subjects With Impaired Glucose Tolerance
Who cites it
29 citing papers in PubMed, 1 synthesis or guideline pooled it, 60 citations in OpenAlex.
- American Association of Clinical Endocrinology Clinical Practice Guideline: Developing a Diabetes Mellitus Comprehensive Care Plan-2022 Update.Endocrine practice : official journal of the American College of Endocrinology and the American Association of Clinical Endocrinologists · 2022Guideline
- Impact of brewer's spent grain (BSG) and bio-transformed BSG biscuits on metabolic and gut health in adults with metabolic impairments: a randomized controlled trial.European journal of nutrition · 2026Trial
- IGF-1 and IGFBP-1 as Possible Predictors of Response to Lifestyle Intervention-Results from Randomized Controlled Trials.International journal of molecular sciences · 2024Trial
- Predicting Factors for Metabolic Non-Response to a Complex Lifestyle Intervention-A Replication Analysis to a Randomized-Controlled Trial.Nutrients · 2022Trial
- A Low Glycemic Index Mediterranean Diet Combined with Aerobic Physical Activity Rearranges the Gut Microbiota Signature in NAFLD Patients.Nutrients · 2022Trial
- Trial
- The Role of Dietary Fibers in the Management of Type 2 Diabetes: A Synthesis of Current Evidence and Clinical Implications.Nutrients · 2026Review
- Metabolic Phenotypes, Genotypes, and Gut Microbiome Signatures in Obesity: Implications for Precision Nutrition Strategies in Type 2 Diabetes Prevention.Nutrition reviews · 2026Review
- Plant-Based Diet for Glycemic Control, Insulin Sensitivity, and Lipid Profile in Type 2 Diabetes: A Systematic Review.Foods (Basel, Switzerland) · 2025Review
- Impact of Dietary Fiber on Inflammation in Humans.International journal of molecular sciences · 2025Review
- Effects of lifestyle intervention and supplementation with insoluble oat fiber on cognitive functions in patients with prediabetes: a secondary analysis of the Optimal Fiber Trial.Frontiers in nutrition · 2025Article
- Bioguided Optimization of the Nutrition-Health, Antioxidant, and Immunomodulatory Properties ofNutrients · 2024Article
- Dietary and Lifestyle Strategies for Obesity.Nutrients · 2024Review
- Article
- High cereal fibre but not total fibre is associated with a lower risk of type 2 diabetes: Evidence from the Melbourne Collaborative Cohort Study.Diabetes, obesity & metabolism · 2023Article
- Metabolic-Associated Fatty Liver Disease and Insulin Resistance: A Review of Complex Interlinks.Metabolites · 2023Review
- Synergistic Effect of Diet and Physical Activity on a NAFLD Cohort: Metabolomics Profile and Clinical Variable Evaluation.Nutrients · 2023Article
- Overview of the Composition of Whole Grains' Phenolic Acids and Dietary Fibre and Their Effect on Chronic Non-Communicable Diseases.International journal of environmental research and public health · 2022Review
- Metabolic and Anthropometric Parameters of Persons at Risk of Developing Type 2 Diabetes Mellitus Before and After 3 Months of Consuming Insoluble Dietary Fiber.Nutrition and metabolic insights · 2022Article
- Dose-dependent effects of insoluble fibre on glucose metabolism: a stratified post hoc analysis of the Optimal Fibre Trial (OptiFiT).Acta diabetologica · 2021Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
10 authors at 4 institutions in 2 countries.
Funding
Abstract
aims/hypothesisInsoluble cereal fibres have been shown in large prospective cohort studies to be highly effective in preventing type 2 diabetes, but there is a lack of interventional data. Our 2 year randomised double-blind prospective intervention study compared the effect of an insoluble oat fibre extract with that of placebo on glucose metabolism and incidence of diabetes.
methodsA total of 180 participants with impaired glucose tolerance underwent a modified version of the 1 year lifestyle training programme PREvention of DIAbetes Self-management (PREDIAS) and were randomised to receive a fibre supplement (n = 89; 7.5 g of insoluble fibre per serving) or placebo (n = 91; 0.8 g of insoluble fibre per serving) twice daily for 2 years. Eligible participants were men and women, were at least 18 years old and did not report corticosteroid or other intensive anti-inflammatory treatment, fibre intolerance or any of the following disorders: overt diabetes, chronic or malignant disease, or severe cardiopulmonary, endocrine, psychiatric, gastrointestinal, autoimmune or eating disorder. Participants were recruited at two clinical wards in Berlin and Nuthetal. The allocation was blinded to participants and study caregivers (physicians, dietitians, study nurses). Randomisation was conducted by non-clinical staff, providing neutrally numbered supplement tins. Both supplements were similar in their visual, olfactory and gustatory appearance. Intention-to-treat analysis was applied to all individuals.
resultsAfter 1 year, 2 h OGTT levels decreased significantly in both groups but without a significant difference between the groups (fibre -0.78 ± 1.88 mmol/l [p ≤ 0.001] vs placebo -0.46 ± 1.80 mmol/l [p = 0.020]; total difference 0.32 ± 0.29 mmol/l; not significant). The 2 year incidence of diabetes was 9/89 (fibre group) compared with 16/91 (placebo group; difference not significant). As secondary outcomes, the change in HbA CONCLUSIONS/
interpretationWe cannot currently provide strong evidence for a beneficial effect of insoluble cereal fibre on glycaemic metabolism, although further studies may support minor effects of fibre supplementation in reducing glucose levels, insulin resistance and the incidence of type 2 diabetes.
trial registrationclinicaltrials.gov NCT01681173 Funding: German Diabetes Foundation (grant no. 232/11/08).
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.