Clinical trial NCT05449665: Focus on Fibre Study
Official title: Healthy Diets for a Healthy Weight: Exploring Physiological Mechanisms Related to Dietary Fibre
Study type: INTERVENTIONAL
Overall status: TERMINATED
Phase: NA
Conditions: Appetitive Behavior
Keywords: fibre
appetite control
gut microbiome
glycaemic control
Lead sponsor: University of Aberdeen
Sponsor class: OTHER
First posted: 2022-07-08
Enrollment: 7
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: BASIC_SCIENCE

Brief 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.


Eligibility criteria: 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

Primary outcomes:
measure: Change in gut hormones to assess appetite response to dietary fibre
timeFrame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measure: Change in subjective hunger to assess appetite response to dietary fibre
timeFrame: At baseline and end of each arm (study days 0, 14, 28 and 42)
Secondary outcomes:
measure: Change in gut metabolites (from faecal samples) in response to dietary fibre
timeFrame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measure: Change in gut microbiome composition (from faecal samples) in response to dietary fibre
timeFrame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measure: Change in glycaemic control in response to dietary fibre
timeFrame: At baseline and end of each arm (study days 0, 14, 28 and 42)
Other outcomes:
measure: Change in blood metabolites in response to dietary fibre
timeFrame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measure: Change in lipid profile in response to dietary fibre
timeFrame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measure: Change in diet markers in response to dietary fibre
timeFrame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measure: Height
timeFrame: At screening visit only
measure: Change in body weight in response to dietary fibre
timeFrame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measure: Change in blood pressure in response to dietary fibre
timeFrame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measure: Change in waist and hip circumferences in response to dietary fibre
timeFrame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measure: Change in waist to hip ratio in response to dietary fibre
timeFrame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measure: Change in Body Mass Index (BMI) in response to dietary fibre
timeFrame: At baseline and end of each arm (study days 0, 14, 28 and 42)
measure: Change in gastrointestinal symptoms in response to dietary fibre
timeFrame: every day of study (42days)
measure: Change in appetite in response to dietary fibre
timeFrame: every day of study (42days)
measure: Change in free-living glycaemic control in response to dietary fibre
timeFrame: every day of study (42days)
measure: Change in food intake
timeFrame: at screening (7days) and every day of study (42days)
Locations:
city: Aberdeen
country: United Kingdom
facility: Rowett Institute, University of Aberdeen
Study officials:
affiliation: Rowett Institute, University of Aberdeen
name: Alexandra Johnstone, Prof
role: PRINCIPAL_INVESTIGATOR
affiliation: Rowett Institute, University of Aberdeen
name: Alexander Ross, Dr
role: PRINCIPAL_INVESTIGATOR
References: