Appetitive Behavior
Conditions
Keywords
fibre, non-nutritive sweetener, weight loss, gut microbiome, glycaemic control
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.
Interventions
OTHERPhase 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).
OTHERPhase 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.
OTHERPhase 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.
Sponsors
University of Aberdeen
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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 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 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 |
| 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 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 |
Countries
United Kingdom
Outcome results
None listed