Focus on Fibre Study

Appetitive Behavior Clinical Trial

Official title:

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

Clinical Trial Details — Status: Terminated

Administrative data

• NCT number: NCT05449665
• Other study ID #: 813
• Status: Terminated
• Phase: N/A
• Start date: June 14, 2022
• Est. completion date: December 31, 2023

Study information

• Verified date: May 2024
• Source: University of Aberdeen
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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.

Recruitment information / eligibility

• Status: Terminated
• Enrollment: 7
• Est. completion date: December 31, 2023
• Est. primary completion date: December 31, 2023
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years and older

Eligibility

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

Related Conditions & MeSH terms

• Appetitive Behavior

Intervention

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).
• 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.
• Phase 3 - Low Fibre
Low Fibre diet (30% Fat, 15% Protein, 55% Carbohydrate, 10g/day Fibre). Fed ad libitum.

Locations

Country	Name	City	State
United Kingdom	Rowett Institute, University of Aberdeen	Aberdeen

Sponsors (1)

Lead Sponsor	Collaborator
University of Aberdeen

Country where clinical trial is conducted

United Kingdom, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Change in blood metabolites in response to dietary fibre	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)
Other	Change in lipid profile in response to dietary fibre	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)
Other	Change in diet markers in response to dietary fibre	measured by change in urinary metabolites	At baseline and end of each arm (study days 0, 14, 28 and 42)
Other	Height	measured in metres	At screening visit only
Other	Change in body weight in response to dietary fibre	measured as weight in kilograms	At baseline and end of each arm (study days 0, 14, 28 and 42)
Other	Change in blood pressure in response to dietary fibre	measured as mmHg on each test day	At baseline and end of each arm (study days 0, 14, 28 and 42)
Other	Change in waist and hip circumferences in response to dietary fibre	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)
Other	Change in waist to hip ratio in response to dietary fibre	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)
Other	Change in Body Mass Index (BMI) in response to dietary fibre	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)
Other	Change in gastrointestinal symptoms in response to dietary fibre	measured daily, at end of day, using questionnaires	every day of study (42days)
Other	Change in appetite in response to dietary fibre	measured daily, at end of day, using visual analogue scale questionnaires	every day of study (42days)
Other	Change in free-living glycaemic control in response to dietary fibre	measured using continuous glucose monitoring (CGM)	every day of study (42days)
Other	Change in food intake	measured using weighed intake records	at screening (7days) and every day of study (42days)
Primary	Change in gut hormones to assess appetite response to dietary fibre	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)
Primary	Change in subjective hunger to assess appetite response to dietary fibre	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	Change in gut metabolites (from faecal samples) in response to dietary fibre	measured by changes in faecal short chain fatty acids concentrations	At baseline and end of each arm (study days 0, 14, 28 and 42)
Secondary	Change in gut microbiome composition (from faecal samples) in response to dietary fibre	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)
Secondary	Change in glycaemic control in response to dietary fibre	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)