SSS: Scot Sweet Study (Interaction of a Non-nutritive Sweetener With a High-fibre Weight Loss Diet)
Study Details
Study Description
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.
Condition or Disease | Intervention/Treatment | Phase |
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N/A |
Study Design
Arms and Interventions
Arm | Intervention/Treatment |
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Experimental: Control-High Fibre Weight Loss-High Fibre Non-Nutritive Sweetener Weight Loss: CTRL-HF WL-HF-NNS WL Phase 1 CTRL: Control diet with moderate fibre consumption for 14days. Phase 2 HF WL: High Fibre Weight Loss meal consumption for 14days. Phase 3 HF-NNS WL: High Fibre and Non-Nutritive Sweetener Weight Loss meal consumption for 14days. |
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:
Other: Phase 2 High Fibre Weight Loss
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:
Other: Phase 3 High Fibre and Non-Nutritive Sweetener Weight Loss
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:
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Outcome Measures
Primary Outcome Measures
- 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
- 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)
- 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
Other Outcome Measures
- Change in concentration of blood metabolites 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 short chain fatty acid (SCFA) concentrations
- Change in concentration of gut hormones 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 ghrelin, GLP-1 and peptide YY (PYY) concentrations
- Change in lipid profile 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 lipid profile (Total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides and non-esterified fatty acids (NEFA)
- Change in lipid ratios in response to dietary fibre and non-nutritive sweetener [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.
- Change in concentration of urinary metabolites in response to dietary fibre and non-nutritive sweetener [At baseline and end of each arm (study days 1, 15, 29 and 43)]
changes in urinary metabolite concentrations measured by metabolomics
- Height [At screening visit only]
measured in metres
- Change in body weight in response to dietary fibre and non-nutritive sweetener [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
- Change in Body Mass Index (BMI) in response to dietary fibre and non-nutritive sweetener [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
- Change in daily nausea symptoms in response to dietary fibre and non-nutritive sweetener [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.
- Change in daily bloating symptoms in response to dietary fibre and non-nutritive sweetener [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.
- Change in daily flatulence symptoms in response to dietary fibre and non-nutritive sweetener [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.
- Change in daily abdominal cramp symptoms in response to dietary fibre and non-nutritive sweetener [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.
- Change in daily intestinal rumble symptoms in response to dietary fibre and non-nutritive sweetener [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.
- Change in daily diarrhoea symptoms in response to dietary fibre and non-nutritive sweetener [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.
- Change in daily constipation symptoms in response to dietary fibre and non-nutritive sweetener [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.
- Change in daily bowel movements in response to dietary fibre and non-nutritive sweetener [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.
- Change in daily hunger rating in response to dietary fibre and non-nutritive sweetener [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).
- Change in daily fullness rating in response to dietary fibre and non-nutritive sweetener [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).
- Change in daily desire to eat rating in response to dietary fibre and non-nutritive sweetener [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).
- Change in retrospective food consumption rating in response to dietary fibre and non-nutritive sweetener [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).
- Change in appetite in response to dietary fibre and non-nutritive sweetener [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)
- Change in food intake [at screening (7days) and every day of study diets (42days)]
measured using weighed intake records
Eligibility Criteria
Criteria
Inclusion Criteria:
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healthy but overweight/obese (BMI 28-40kg/m2) males and females (postmenopausal, using the oral contraceptive pill or some form of hormonal contraceptive)
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moderate habitual fibre intake (18-23g/day)
Exclusion Criteria:
Medication exclusion criteria:
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antibiotic use (within the past 3 months due to impact on gut microbiota)
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anti-depressants (current)
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smoking or vaping
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weight loss medication
Medical exclusion criteria:
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Females who are planning to be pregnant, are pregnant or are breastfeeding
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Anyone with food allergies, self-reported food sensitivity or intolerance
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Anyone with coeliac disease or gluten intolerance
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Anyone taking medication which may affect their appetite
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Anyone with an eating disorder
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Anyone with diabetes
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Anyone with a gastrointestinal disorder, kidney disease, liver disease or gout
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Anyone suffering from a psychiatric disorder or any type of substance abuse
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Anyone suffering from unregulated thyroid disease
Other exclusion criteria:
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Anyone following a vegetarian or vegan diet
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Anyone following a current weight loss programme (that may be affecting lifestyle, physical activity & diet) or undergone gastric band/reduction surgery
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Anyone with unsuitable veins for blood sampling
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Anyone who is unable to fluently speak, read and understand English
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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.
Contacts and Locations
Locations
Site | City | State | Country | Postal Code | |
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1 | Rowett Institute, University of Aberdeen | Aberdeen | United Kingdom | AB25 2ZD |
Sponsors and Collaborators
- University of Aberdeen
Investigators
- Principal Investigator: Alexandra Johnstone, Prof, Rowett Institute, University of Aberdeen
- Principal Investigator: Alexander Ross, Dr, Rowett Institute, University of Aberdeen
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- 814