Focus on Fibre Study

May 8, 2024 updated by: University of Aberdeen

Healthy Diets for a Healthy Weight: Exploring Physiological Mechanisms Related to Dietary Fibre

The investigators present a diet intervention study, to be conducted as a within-subject design, with all food and beverages provided, to allow ad libitum feeding to assess impact of diet change on appetite response. The diets will vary in fibre content and type. This study will allow assessment of the physiological impact of dietary fibre on markers of appetite control for body weight, measured from plasma gut hormones. The investigators propose to recruit participants with a poor diet quality (low habitual fibre intake) to additionally examine the time-course of adaptation of the gut microbiome (measured in faecal samples), whilst assessing the impact of added fibre on body weight and subjective appetite scores. This approach is to address the impact of dietary fibre in people living with obesity and food inequalities. The investigators will assess physiological bio-markers of appetite control and their contribution to the development of a gut ecosystem that promotes health. A subsequent period of return to a low fibre feeding will allow assessment of durability of response.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Terminated

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
7

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • United Kingdom
      • Aberdeen, United Kingdom, AB25 2ZD
        • Rowett Institute, University of Aberdeen

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • healthy but overweight/obese (BMI 28-40kg/m2) males and females (post-menopausal, using the oral contraceptive pill or some form of hormonal contraceptive)
  • low habitual fibre intake (<10g/day)

Exclusion Criteria:

Medication exclusion criteria:

  • antibiotic use (within the past 3 months due to impact on gut microbiota)
  • statins (current)
  • aspirin or other NSAIDs or anti-coagulants (current)
  • anti-depressants (current)
  • smoking or vaping

Medical exclusion criteria:

  • Females who are planning to be pregnant, are pregnant or are breastfeeding
  • Anyone with food allergies, self-reported food sensitivity or intolerance
  • Anyone with coeliac disease or gluten intolerance
  • Anyone taking medication which may affect their appetite
  • Anyone with an eating disorder
  • Anyone with diabetes
  • Anyone with a gastrointestinal disorder, kidney disease, liver disease or gout
  • Anyone suffering from a psychiatric disorder or any type of substance abuse
  • Anyone suffering from unregulated thyroid disease

Other exclusion criteria:

  • Anyone following a vegetarian or vegan diet
  • Anyone following a weight loss programme (that may be affecting lifestyle, physical activity & diet)
  • Anyone with unsuitable veins for blood sampling
  • Anyone who is unable to fluently speak, read and understand English
  • Anyone who is unable to comply to an alcohol-free diet for 6 weeks

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Experimental: Control - High Fibre - Low Fibre (CTRL - HF - LF)
  • Phase 1 - CTRL: Control diet with moderate fibre consumption for 13days.
  • Phase 2 - HF: ad libitum consumption of HF meals for 13days.
  • Phase 3 - LF: ad libitum consumption of LF meals for 13days.
Other: Phase 1 - Control

Control diet (30% Fat, 15% Protein, 55% Carbohydrate, Fibre rising from 10 to 16g/d).

Fed to energy balance (1.5 x Resting Metabolic Rate, RMR).

Other Names:
  • Phase 1 - CTRL
Other: Phase 2 - High Fibre
High Fibre diet (30% Fat, 15% Protein, 55% Carbohydrate, 30g/day Fibre). Fed ad libitum, contains 20g/day pectin (split over breakfast, lunch and dinner) in drinks/yoghurts which will be compulsory to consume and 10g/day fibre coming from the diet provided.
Other Names:
  • HF
Other: Phase 3 - Low Fibre
Low Fibre diet (30% Fat, 15% Protein, 55% Carbohydrate, 10g/day Fibre). Fed ad libitum.
Other Names:
  • LF

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in gut hormones to assess appetite response to dietary fibre
Time Frame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measured by acute and chronic changes in plasma ghrelin and peptide YY (PYY)
At baseline and end of each arm (study days 0, 14, 28 and 42)
Change in subjective hunger to assess appetite response to dietary fibre
Time Frame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measured by acute and chronic changes in appetite using visual analogue scale questionnaires
At baseline and end of each arm (study days 0, 14, 28 and 42)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in gut metabolites (from faecal samples) in response to dietary fibre
Time Frame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measured by changes in faecal short chain fatty acids concentrations
At baseline and end of each arm (study days 0, 14, 28 and 42)
Change in gut microbiome composition (from faecal samples) in response to dietary fibre
Time Frame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measured by changes in bacterial 16S ribosomal ribonucleic acid gene sequencing; 16S rRNA
At baseline and end of each arm (study days 0, 14, 28 and 42)
Change in glycaemic control in response to dietary fibre
Time Frame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measured by acute and chronic changes in plasma glucose and insulin
At baseline and end of each arm (study days 0, 14, 28 and 42)

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in blood metabolites in response to dietary fibre
Time Frame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measured by acute and chronic changes in plasma short chain fatty acids (SCFA)
At baseline and end of each arm (study days 0, 14, 28 and 42)
Change in lipid profile in response to dietary fibre
Time Frame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measured by change in fasting plasma lipid profile (cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and non-esterified fatty acids (NEFA)
At baseline and end of each arm (study days 0, 14, 28 and 42)
Change in diet markers in response to dietary fibre
Time Frame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measured by change in urinary metabolites
At baseline and end of each arm (study days 0, 14, 28 and 42)
Height
Time Frame: At screening visit only
measured in metres
At screening visit only
Change in body weight in response to dietary fibre
Time Frame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measured as weight in kilograms
At baseline and end of each arm (study days 0, 14, 28 and 42)
Change in blood pressure in response to dietary fibre
Time Frame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measured as mmHg on each test day
At baseline and end of each arm (study days 0, 14, 28 and 42)
Change in waist and hip circumferences in response to dietary fibre
Time Frame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measured as in cm with a tape measure on each test day
At baseline and end of each arm (study days 0, 14, 28 and 42)
Change in waist to hip ratio in response to dietary fibre
Time Frame: At baseline and end of each arm (study days 0, 14, 28 and 42)
waist and hip measures will be combined to report waist to hip ratio
At baseline and end of each arm (study days 0, 14, 28 and 42)
Change in Body Mass Index (BMI) in response to dietary fibre
Time Frame: At baseline and end of each arm (study days 0, 14, 28 and 42)
weight and height measures will be combined to report BMI in kg/m^2
At baseline and end of each arm (study days 0, 14, 28 and 42)
Change in gastrointestinal symptoms in response to dietary fibre
Time Frame: every day of study (42days)
measured daily, at end of day, using questionnaires
every day of study (42days)
Change in appetite in response to dietary fibre
Time Frame: every day of study (42days)
measured daily, at end of day, using visual analogue scale questionnaires
every day of study (42days)
Change in free-living glycaemic control in response to dietary fibre
Time Frame: every day of study (42days)
measured using continuous glucose monitoring (CGM)
every day of study (42days)
Change in food intake
Time Frame: at screening (7days) and every day of study (42days)
measured using weighed intake records
at screening (7days) and every day of study (42days)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Aberdeen

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Alexandra Johnstone, Prof, Rowett Institute, University of Aberdeen
  • Principal Investigator: Alexander Ross, Dr, Rowett Institute, University of Aberdeen

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 14, 2022

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2023

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2023

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 17, 2022

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 4, 2022

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
July 8, 2022

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 10, 2024

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 8, 2024

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2024

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 813

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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