Scot Sweet Study (Interaction of a Non-nutritive Sweetener With a High-fibre Weight Loss Diet)

Not Applicable

Completed

• Conditions: Appetitive Behavior

• Registration Number: NCT05892003
• Lead Sponsor: University of Aberdeen

Brief Summary

The investigators present a weight loss diet intervention study, to be conducted as a within-subject design, with all food and beverages provided, to assess interaction of non-nutritive sweetener (sucralose) with a high-fibre weight loss diet, on markers of gut health in humans. This study will allow assessment of the effects of a non-nutritive sweetener (sucralose) with a high-fibre (soluble fibre, fructo-oligosaccharides, FOS) diet on metabolic health and activity and composition of gut microbiota, by a controlled human diet intervention study. The investigators propose to recruit participants living with obesity, with a poor diet quality (moderate habitual fibre intake) to additionally address diet inequalities in the research approach, and this will also allow examine the time-course of adaptation of the gut microbiome (measured in faecal samples). The investigators will also assess changes in free-living glycaemic control with addition of dietary fibre and bio-markers of health.

Detailed Description

Not available

Study Timeline

• Study Start: 2023-05-12
• Study First Submitted: 2023-05-17
• Study First Submitted QC: 2023-05-26
• Study First Posted: 2023-06-07
• Primary Completion: 2024-12-16
• Study Completion: 2024-12-16
• Status Verified: 2025-01
• Last Update Submitted: 2025-01-06
• Last Update Posted: 2025-01-07

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• healthy but overweight/obese (BMI 28-40kg/m2) males and females (postmenopausal, using the oral contraceptive pill or some form of hormonal contraceptive)
• moderate habitual fibre intake (18-23g/day)

Exclusion Criteria

Medication exclusion criteria:

• antibiotic use (within the past 3 months due to impact on gut microbiota)
• anti-depressants (current)
• smoking or vaping
• weight loss medication

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 current weight loss programme (that may be affecting lifestyle, physical activity & diet) or undergone gastric band/reduction surgery
• 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

Current sweetener consumption will not be an exclusion criteria as the Phase 1 - CTRL and Phase 2 - HF WL diets will provide enough of a washout (4 weeks) before the Phase 3 diets containing sucralose are consumed. Participants who do habitually consume sweeteners will be asked not to use them during the study.

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Primary Outcome Measures

Name	Time	Method
Change in gut metabolites (from faecal samples) in response to dietary fibre and non-nutritive sweetener	At baseline and end of each arm (study days 1, 15, 29 and 43)	Measured by changes in faecal short chain fatty acids concentrations
Change in gut microbiome composition (from faecal samples) in response to dietary fibre and non-nutritive sweetener	At baseline and end of each arm (study days 1, 15, 29 and 43)	Measured by changes in bacterial 16S ribosomal ribonucleic acid gene sequencing; 16S rRNA
Change in gut metabolite production (from faecal samples) in response to dietary fibre and non-nutritive sweetener	At baseline and end of each arm (study days 1, 15, 29 and 43)	Measured by changes in calprotectin concentrations

Secondary Outcome Measures

Name	Time	Method
Change in glycaemic control in response to dietary fibre and non-nutritive sweetener	At baseline and end of each arm (study days 1, 15, 29 and 43)	measured by changes in fasted plasma glucose and insulin
Change in free-living glycaemic control in response to dietary fibre and non-nutritive sweetener	every day of study diets (42days)	measured using continuous glucose monitoring (CGM)

Trial Locations

Locations (1)

Rowett Institute, University of Aberdeen; 🇬🇧 Aberdeen, United Kingdom