Skip to main content
OpenTrials
Completed

NCT Number: NCT05892003

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

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.

Completed

Looking for future studies?

Notify Me

Key information

Conditions

Appetitive Behavior Behavior Behavior, Animal Body Weight Body Weight Changes Pathological Conditions, Signs and Symptoms Signs and Symptoms Weight Loss

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Rowett Institute, University of Aberdeen

Aberdeen, AB25 2ZD, United Kingdom

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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.

Treatment and study plan

Phase 1 Control

Other

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: CTRL

Phase 2 High Fibre Weight Loss

Other

High Fibre Weight Loss diet (30% Fat, 15% Protein, 55% Carbohydrate). Fed to energy deficit (100% RMR). The quantity of fructo-oligosaccharides (FOS) will be fixed at 20g/day for all kcal levels with additional fibre coming from the diet provided. The FOS will be split over breakfast, lunch and dinner in drinks/yoghurts which will be compulsory to consume.

Other names: HF WL

Phase 3 High Fibre and Non-Nutritive Sweetener Weight Loss

Other

High Fibre and Non-Nutritive Sweetener Weight Loss diet (30% Fat, 15% Protein, 55% Carbohydrate). Fed to energy deficit (100% RMR). The quantity of fructo-oligosaccharides (FOS) and non-nutritive sweetener (sucralose) will be fixed at 20g/day and 30mg/day respectively for all kcal levels with additional fibre coming from the diet provided. The FOS and sucralose will be split over breakfast, lunch and dinner in drinks/yoghurts which will be compulsory to consume.

Other names: HF-NNS WL

Primary outcomes

  1. Change in gut metabolites (from faecal samples) in response to dietary fibre and non-nutritive sweetener

    Time frame: At baseline and end of each arm (study days 1, 15, 29 and 43)

    Measured by changes in faecal short chain fatty acids concentrations

  2. Change in gut microbiome composition (from faecal samples) in response to dietary fibre and non-nutritive sweetener

    Time frame: 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

  3. Change in gut metabolite production (from faecal samples) in response to dietary fibre and non-nutritive sweetener

    Time frame: At baseline and end of each arm (study days 1, 15, 29 and 43)

    Measured by changes in calprotectin concentrations

Secondary outcomes

  1. Change in free-living glycaemic control in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    measured using continuous glucose monitoring (CGM)

  2. Change in glycaemic control in response to dietary fibre and non-nutritive sweetener

    Time frame: At baseline and end of each arm (study days 1, 15, 29 and 43)

    measured by changes in fasted plasma glucose and insulin

Other outcomes

  1. Change in concentration of blood metabolites in response to dietary fibre and non-nutritive sweetener

    Time frame: At baseline and end of each arm (study days 1, 15, 29 and 43)

    measured by changes in fasted plasma short chain fatty acid (SCFA) concentrations

  2. Change in concentration of gut hormones in response to dietary fibre and non-nutritive sweetener

    Time frame: At baseline and end of each arm (study days 1, 15, 29 and 43)

    measured by changes in fasted plasma ghrelin, GLP-1 and peptide YY (PYY) concentrations

  3. Change in lipid profile in response to dietary fibre and non-nutritive sweetener

    Time frame: At baseline and end of each arm (study days 1, 15, 29 and 43)

    measured by changes in fasted plasma lipid profile (Total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and non-esterified fatty acids (NEFA)

  4. Change in lipid ratios in response to dietary fibre and non-nutritive sweetener

    Time frame: At baseline and end of each arm (study days 1, 15, 29 and 43)

    Total cholesterol, HDL-cholesterol and LDL-cholesterol measures will be combined to report TC to HDL and LDL to HDL ratios.

  5. Change in concentration of urinary metabolites in response to dietary fibre and non-nutritive sweetener

    Time frame: At baseline and end of each arm (study days 1, 15, 29 and 43)

    changes in urinary metabolite concentrations measured by metabolomics

  6. Height

    Time frame: At screening visit only

    measured in metres

  7. Change in body weight in response to dietary fibre and non-nutritive sweetener

    Time frame: At screening and 3 times a week on each arm (20 occasions from date of screening up to study day 43)

    measured as weight in kilograms

  8. Change in Body Mass Index (BMI) in response to dietary fibre and non-nutritive sweetener

    Time frame: At screening and 3 times a week on each arm (20 occasions from date of screening up to study day 43)

    weight and height measures will be combined to report BMI in kg/m^2

  9. Change in daily nausea symptoms in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    measured daily, at end of day, using questionnaires. Question presented as a Likert scale 'Have you experienced nausea today?', scored as 0 - no more symptoms than usual, 1 - slightly more symptoms than usual, 2 - noticeably more symptoms than usual, 3 - considerably more symptoms than usual.

  10. Change in daily bloating symptoms in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    measured daily, at end of day, using questionnaires. Question presented as a Likert scale 'Have you experienced bloating today?', scored as 0 - no more symptoms than usual, 1 - slightly more symptoms than usual, 2 - noticeably more symptoms than usual, 3 - considerably more symptoms than usual.

  11. Change in daily flatulence symptoms in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    measured daily, at end of day, using questionnaires. Question presented as a Likert scale 'Have you experienced flatulence today?', scored as 0 - no more symptoms than usual, 1 - slightly more symptoms than usual, 2 - noticeably more symptoms than usual, 3 - considerably more symptoms than usual.

  12. Change in daily abdominal cramp symptoms in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    measured daily, at end of day, using questionnaires. Question presented as a Likert scale 'Have you experienced abdominal cramps today?', scored as 0 - no more symptoms than usual, 1 - slightly more symptoms than usual, 2 - noticeably more symptoms than usual, 3 - considerably more symptoms than usual.

  13. Change in daily intestinal rumble symptoms in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    measured daily, at end of day, using questionnaires. Question presented as a Likert scale 'Have you experienced rumbles today? (intestinal sounds)', scored as 0 - no more symptoms than usual, 1 - slightly more symptoms than usual, 2 - noticeably more symptoms than usual, 3 - considerably more symptoms than usual.

  14. Change in daily diarrhoea symptoms in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    measured daily, at end of day, using questionnaires. Question presented as a Likert scale 'Have you experienced diarrhoea today?', scored as 0 - no more symptoms than usual, 1 - slightly more symptoms than usual, 2 - noticeably more symptoms than usual, 3 - considerably more symptoms than usual.

  15. Change in daily constipation symptoms in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    measured daily, at end of day, using questionnaires. Question presented as a Likert scale 'Have you experienced constipation today?', scored as 0 - no more symptoms than usual, 1 - slightly more symptoms than usual, 2 - noticeably more symptoms than usual, 3 - considerably more symptoms than usual.

  16. Change in daily bowel movements in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    measured daily, at end of day, using questionnaires. Question presented as a scale 'How many bowel movements have you had today?', scored as 0, 1, 2, 3 or >3.

  17. Change in daily hunger rating in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    measured daily, at end of day, using questionnaires. Question presented as a visual analogue scale 'How hungry have you felt today?', scored from 0 (Generally not at all hungry) to 100 (Generally as hungry as I've ever felt).

  18. Change in daily fullness rating in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    measured daily, at end of day, using questionnaires. Question presented as a visual analogue scale 'How full have you felt today?', scored from 0 (Generally not at all full) to 100 (Generally as full as I've ever felt).

  19. Change in daily desire to eat rating in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    measured daily, at end of day, using questionnaires. Question presented as a visual analogue scale 'How strong has your desire to eat been today?', scored from 0 (Very weak) to 100 (Very strong).

  20. Change in retrospective food consumption rating in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    measured daily, at end of day, using questionnaires. Question presented as a visual analogue scale 'How much do you feel you could have eaten today?', scored from 0 (Nothing at all) to 100 (A large amount).

  21. Change in appetite in response to dietary fibre and non-nutritive sweetener

    Time frame: every day of study diets (42days)

    Mean of hunger, fullness, desire to eat and retrospective consumption ratings will be combined to report an overall appetite score (from 0 to 100)

  22. Change in food intake

    Time frame: at screening (7days) and every day of study diets (42days)

    measured using weighed intake records

Sponsors and collaborators

Lead sponsor

University of Aberdeen

Other

Registry information

Official study title

Healthy Diets for a Healthy Weight: Exploring Physiological Mechanisms Related to Dietary Fibre and Non-Nutritive Sweeteners

Acronym: SSS

Important dates

Study start
2023
Primary completion
2024
Study completion
2024
First posted
Jun 7, 2023
Registry last updated
Jan 7, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Related clinical trials

Published trials that share one or more normalized conditions with this study.