DiabetesNCT01681173
OPTIFIT-Optimal Fiber Trial for Diabetes Prevention
A study testing Fiber in people with Diabetes and Nutrition Disorders, run by German Institute of Human Nutrition at 2 sites in Germany.
Trial summary
High intake of insoluble fiber is strongly associated with a reduced incidence of diabetes and cardiovascular events in prospective observation studies. Our primary objective is to compare a life style diabetes prevention program(PRAEDIAS) with and without added insoluble fibers in its effectiveness to prevent… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Diabetes, Nutrition Disorders, Obesity
- What is being tested?
- Fiber
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 200 participants
- Where
- 2 sitesGermany
- Study dates
- May 2010to Dec 2014
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Impaired glucose tolerance
- Age>18years old
- both gender
Who cannot join
- Diabetes type 1 and type 2
- chronic or malignant disease
- Intake of metabolic influence drugs
- Food allergies, fiber intolerance
Trial locations and contacts
2 sites in 1 country.
Germany2 sites
Charite University
Berlin, State of Berlin, 12200
German Instiute of Human Nutrition
Potsdam-Rehbruecke, Nuthetal, 14558
About this study
Official title: 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
High intake of insoluble fiber is strongly associated with a reduced incidence of diabetes and cardiovascular events in prospective observation studies. Our primary objective is to compare a life style diabetes prevention program(PRAEDIAS) with and without added insoluble fibers in its effectiveness to prevent incident diabetes type 2 in high risk individuals with impaired glucose tolerance. Subjects with IGT not willing to participate in the intervention will be used as independent controls. Secondary aims are to identify mechanisms of action with regard to body composition, anti-inflammatory and metabolic effects of fibers. We propose a randomized, prospective intervention study. The results will be of general relevance for guidance of fiber intake in the population and will help the food industry to design healthy high fiber foods. Fiber can be added at low cost to numerous foods. Increased fiber intake may therefore provide a simple non-cognitive prevention strategy effective at the population level.
Read the detailed description
The overall objective is to investigate whether insoluble fibers added to standard nutrition can reduce the progression of impairment of glucose metabolism in a high risk population with impaired glucose metabolism. Large prospective cohort studies clearly show that mainly insoluble cereal fiber from whole grains is associated with reduced risk of type 2 diabetes and cardiovascular disease. However, there is a lack of evidence from prospective intervention studies targeted to evaluate the potential of dietary fibers to reduce diabetes and cardiovascular disease as recently stated by the Cochrane Foundation. Dietary fiber intake is generally much lower than currently recommended, which may in part be related to side effects of whole grain nutrients and their gustatory properties. Intestinally uncomfortable effects are at least partly related to fermentation which is much less induced by insoluble non-fermentable fibers than by soluble fermentable fibers. The prospective demonstration of beneficial effects of insoluble fibers in preventing diabetes type 2 will allow detailed nutritional recommendations. This may serve to support the consumption of metabolically beneficial constituents of fiber-rich diets and help to increase fiber intake by high fiber natural nutrients or everyday nutrients enriched in insoluble natural fibers.
- Conditions
- Diabetes, Nutrition Disorders, Obesity, Overweight, Metabolic Syndrome x, Body Weight
- Being tested
- Fiber, Placebo
- Keywords
- Nutritional support, Diet therapy, Diabetes prevention, Insoluble fiber, Healthy life style, Weight loss
- Medical subject headings
- Diabetes Mellitus, Nutrition Disorders, Obesity, Overweight, Metabolic Syndrome, Body Weight, Glucose Metabolism Disorders, Metabolic Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
FiberDietary supplement
200ml drinks enriched with 7,5g of fiber (90% insoluble fiber, 10% soluble fiber), BID, over 24 months
PlaceboDietary supplement
200ml Placebo, BID, over 24 months
| Study group | Role | What they receive |
|---|---|---|
| Drink enriched in fibers | Experimental | 7,5g enriched fiber drinks, BID Receives: Dietary Supplement: Fiber |
| Placebo drink | Experimental | Placebo drink, BID Receives: Dietary Supplement: Placebo |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change of 2h-postprandial blood glucose from IGT to diabetes mellitus type 2 or normal glucose tolerance (NGT)
Change of the glucose metabolism (OGTT)
Measured: 0, 12, 24 months
Secondary outcomes (7)
Change of insulin sensitivity
Measurement by HOMA and OGIS from the OGTT
Measured: 0, 12, 24 months
Change of insulin secretion
Measurement by the OGTT
Measured: 0, 12, 24 months
Expression of inflammatory markers in blood
CRP, leukocytes, adipocytokines
Measured: 0, 6, 12, 18, 24 months
Biometric data
Nutritional impact of blood pressure, anthropometry (body weight and body composition)
Measured: 0, 6, 12, 18, 24 months
Assessment of cognitive performance
Measured: 0, 12, 24 months
Development of indices for the prediction of fat mass
Change of fat fraction in liver, abdominal and in the total body fat measuring by MRI/H1-spectroscopy
Measured: 0, 12, 24 months
Determination of gene expression in adipose tissue
Determination of inflammatory and other transcripts in sc adipose tissue in a fat biopsy.
Measured: 0, 12, 24 month
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 Sep 2012 (estimated)
- Study startMay 2010
- Primary completionDec 2014
- Study completionDec 2014
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for DiabetesStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind
- Who is masked
- Participant, Care provider, Investigator
- Enrolment
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- German Institute of Human Nutrition
- Sponsor type
- University, hospital or other
- Collaborators
- Charite University, Berlin, Germany, German Diabetes Foundation, Munich, Germany, Ernst von Bergmann Hospital, University Hospital Tuebingen
- Responsible party
- Principal investigator, Prof. Dr. med. Andreas F. H. Pfeiffer, German Institute of Human Nutrition
- Investigators
- Andreas FH Pfeiffer, Prof., Principal investigator, German Institute of Human Nutrition Potsdam-Rehbruecke
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT01681173
- Sponsor's protocol ID
- DDS-FKZ 232/11/08
- Status last verified
- Feb 2015
- First submitted
- 5 Sep 2012
- Last updated
- 5 Feb 2015
- Results posted
- No
- Data monitoring committee
- No
Publications
Kabisch S, Montagna F, Honsek C, Kemper M, Gerbracht C, Arafat AM, Birkenfeld AL, Dambeck U, Osterhoff MA, Weickert MO, Floel A, Pfeiffer AFH. 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. Front Nutr. 2026 Jan 16;12:1699958. doi: 10.3389/fnut.2025.1699958. eCollection 2025.
PubMed 41624204Honsek C, Kabisch S, Kemper M, Gerbracht C, Arafat AM, Birkenfeld AL, Dambeck U, Osterhoff MA, Weickert MO, Pfeiffer AFH. Fibre supplementation for the prevention of type 2 diabetes and improvement of glucose metabolism: the randomised controlled Optimal Fibre Trial (OptiFiT). Diabetologia. 2018 Jun;61(6):1295-1305. doi: 10.1007/s00125-018-4582-6. Epub 2018 Feb 28.
PubMed 29492637
Study at a glance
From the registry record, last updated by the sponsor on 5 Feb 2015. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- 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
- ClinicalTrials.gov ID
- NCT01681173
- Acronym / sponsor ID
- DDS-FKZ 232/11/08
- Conditions
- Diabetes, Nutrition Disorders, Obesity, Overweight, Metabolic Syndrome x, Body Weight
- Keywords
- Nutritional support, Diet therapy, Diabetes prevention, Insoluble fiber, Healthy life style, Weight loss
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- German Institute of Human NutritionUniversity, hospital or other
- Collaborators
- Charite University, Berlin, Germany, German Diabetes Foundation, Munich, Germany, Ernst von Bergmann Hospital, University Hospital Tuebingen
- Study start
- May 2010
- Primary completion
- Dec 2014 (actual)
- Study completion
- Dec 2014 (actual)
- First posted
- 7 Sep 2012 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
High intake of insoluble fiber is strongly associated with a reduced incidence of diabetes and cardiovascular events in prospective observation studies. Our primary objective is to compare a life style diabetes prevention program(PRAEDIAS) with and without added insoluble fibers in its effectiveness to prevent incident diabetes type 2 in high risk individuals with impaired glucose tolerance. Subjects with IGT not willing to participate in the intervention will be used as independent controls. Secondary aims are to identify mechanisms of action with regard to body composition, anti-inflammatory and metabolic effects of fibers. We propose a randomized, prospective intervention study. The results will be of general relevance for guidance of fiber intake in the population and will help the food industry to design healthy high fiber foods. Fiber can be added at low cost to numerous foods. Increased fiber intake may therefore provide a simple non-cognitive prevention strategy effective at the population level.
Detailed description
The overall objective is to investigate whether insoluble fibers added to standard nutrition can reduce the progression of impairment of glucose metabolism in a high risk population with impaired glucose metabolism. Large prospective cohort studies clearly show that mainly insoluble cereal fiber from whole grains is associated with reduced risk of type 2 diabetes and cardiovascular disease. However, there is a lack of evidence from prospective intervention studies targeted to evaluate the potential of dietary fibers to reduce diabetes and cardiovascular disease as recently stated by the Cochrane Foundation. Dietary fiber intake is generally much lower than currently recommended, which may in part be related to side effects of whole grain nutrients and their gustatory properties. Intestinally uncomfortable effects are at least partly related to fermentation which is much less induced by insoluble non-fermentable fibers than by soluble fermentable fibers. The prospective demonstration of beneficial effects of insoluble fibers in preventing diabetes type 2 will allow detailed nutritional recommendations. This may serve to support the consumption of metabolically beneficial constituents of fiber-rich diets and help to increase fiber intake by high fiber natural nutrients or everyday nutrients enriched in insoluble natural fibers.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Triple blind (participant, care provider, investigator)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Drink enriched in fibers | Experimental | Dietary Supplement: Fiber7,5g enriched fiber drinks, BID |
| Placebo drink | Experimental | Dietary Supplement: PlaceboPlacebo drink, BID |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- Impaired glucose tolerance
- Age>18years old
- both gender
Key exclusion criteria (4 listed)
- Diabetes type 1 and type 2
- chronic or malignant disease
- Intake of metabolic influence drugs
- Food allergies, fiber intolerance
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Fiber200ml drinks enriched with 7,5g of fiber (90% insoluble fiber, 10% soluble fiber), BID, over 24 months | Dietary supplement | Drink enriched in fibers |
| Placebo200ml Placebo, BID, over 24 months | Dietary supplement | Placebo drink |
Primary outcome
Change of 2h-postprandial blood glucose from IGT to diabetes mellitus type 2 or normal glucose tolerance (NGT)
Time frame: 0, 12, 24 months
Change of the glucose metabolism (OGTT)
7 secondary outcomes
Change of insulin sensitivity
Time frame: 0, 12, 24 months
Change of insulin secretion
Time frame: 0, 12, 24 months
Expression of inflammatory markers in blood
Time frame: 0, 6, 12, 18, 24 months
Biometric data
Time frame: 0, 6, 12, 18, 24 months
Assessment of cognitive performance
Time frame: 0, 12, 24 months
Development of indices for the prediction of fat mass
Time frame: 0, 12, 24 months
Determination of gene expression in adipose tissue
Time frame: 0, 12, 24 month
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Feb 2015.
- Derived from this study: PubMed 41624204Kabisch S, Montagna F, Honsek C, Kemper M, Gerbracht C, Arafat AM, Birkenfeld AL, Dambeck U, Osterhoff MA, Weickert MO, Floel A, Pfeiffer AFH. 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. Front Nutr. 2026 Jan 16;12:1699958. doi: 10.3389/fnut.2025.1699958. eCollection 2025.
- Derived from this study: PubMed 29492637Honsek C, Kabisch S, Kemper M, Gerbracht C, Arafat AM, Birkenfeld AL, Dambeck U, Osterhoff MA, Weickert MO, Pfeiffer AFH. Fibre supplementation for the prevention of type 2 diabetes and improvement of glucose metabolism: the randomised controlled Optimal Fibre Trial (OptiFiT). Diabetologia. 2018 Jun;61(6):1295-1305. doi: 10.1007/s00125-018-4582-6. Epub 2018 Feb 28.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Andreas FH Pfeiffer, Prof. principal investigator
German Institute of Human Nutrition Potsdam-Rehbruecke
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Fiber in people with Diabetes and Nutrition Disorders, run by German Institute of Human Nutrition at 2 sites in Germany.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 4 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Feb 2015. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Germany. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change of 2h-postprandial blood glucose from IGT to diabetes mellitus type 2 or normal glucose tolerance (NGT) (time frame: 0, 12, 24 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT01681173, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Feb 2015.