Sweet Consumption and Subsequent Sweet Food Preferences and Intakes

Study Overview
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Brief Summary
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This study will assess the effects of repeated sweet versus non-sweet food consumption on subsequent sweet and non-sweet food preferences and intakes.

Detailed Description
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Participants will be randomized to receive instructions to either increase, decrease or make no change to sweet food consumption for 6 days, and impacts on food preferences and intakes will be assessed at baseline and after 1 week. Preferences for sweet and non-sweet foods will be assessed during a taste test at each assessment time, where six different foods will be rated. Sweet and non-sweet food consumption will also be measured at a subsequent breakfast at the assessment time. Buffet meals composed of sweet and non-sweet foods suitable for consumption at breakfast will be provided ad-libitum. A subset of participants (selected at random) (10 participants randomized to increase sweet food consumption and 10 participants randomized to decrease sweet food consumption) will also be assessed via MRI and fMRI scanning to investigate brain structure and functional connectivity.

Official Title
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Sweet Consumption and Subsequent Sweet Food Preferences and Intakes

Conditions
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Dietary Behaviour

Intervention / Treatment
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* Behavioral: Dietary Instructions


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: aged 18-65 years; habitually consume breakfast; able to provide consent and complete all study materials; able to attend Bournemouth University for testing. Exclusion criteria: individuals who are pregnant or breastfeeding; underweight (BMI <18.5); have pre-existing clinical conditions such as diabetes mellitus, eating disorders, Crohn's disease and other illness's leading to participants receiving external nutritional advice and dietary restrictions; have pre-existing medical conditions affecting swallow ability, taste and smell perception; currently or within 3 months of starting the study are following a specific dietary programme (e.g.: Slimming World); current smokers or have smoked within 3 months of the study start date.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Dietary Instructions: Increase sweet food consumption<br>Participants are asked to increase their consumption of sweet foods throughout their diet. Participants will be provided with clear instructions, where sweet foods will be highlighted and additional means of increasing sweet food consumption will be offered. | Behavioral: Dietary Instructions<br>* Dietary Instructions<br>|
| Active Comparator: Dietary Instructions: Decrease sweet food consumption<br>Participants are asked to decrease their consumption of sweet foods throughout their diet. Participants will be provided with clear instructions, where sweet foods will be highlighted and means of decreasing sweet food consumption will be offered. | Behavioral: Dietary Instructions<br>* Dietary Instructions<br>|
| Placebo Comparator: Dietary Instructions: Usual Diet<br>Participants are asked to retain their consumption of sweet foods throughout their diet. | Behavioral: Dietary Instructions<br>* Dietary Instructions<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sweet food preferences | Preferences for various sweet foods/fluids, assessed using a taste test, where participants sample several sweet and non-sweet foods and rate them for pleasantness on a 100mm Visual Analogue Scale. Higher scores signify stronger preferences | Baseline to week 1 | 
| Sweet food choices | Selection of sweet foods/fluids at a given meal, assessed where participants can consume freely from a meal composed of sweet and non-sweet foods, and proportion of sweet foods consumed is measured in terms of weight consumed | Baseline to week 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Hunger and Thirst | Ratings of subjective perceptions, assessed using 100mm VAS | Baseline to week 1 | 
| Sweet food perceptions | Perceptions for various sweet foods/fluids, assessed using a taste test, where participants sample several sweet and non-sweet foods and rate them for intensity on a 100mm Visual Analogue Scale. Higher scores signify stronger perceptions | Baseline to week 1 | 
| MRI static brain scan (subset of participants only) | Static brain scan gained from a 3-Tesla Siemens Magnetom Lumina scanner (Siemens Healthcare, Erlangen, Germany), used to investigate brain structure, where the anatomical structure (e.g. size, shape) of the brain, measured via surface area (mm squared), will be compared at baseline and week 1 | Baseline to week 1 | 
| fMRI composite functional brain scan (subset of participants only) | Composite fMRI functional scan to investigate brain functionality and connectivity in response to a 10 min cognitive task, will be gained from a 3-Tesla Siemens Magnetom Lumina scanner (Siemens Healthcare, Erlangen, Germany), where patterns of activity will be measured using blood oxygenation level-dependent (BOLD) contrast whole-brain functional images, acquired using a T2-weighted gradient-echo Echo Planar Imaging (EPI) sequence and a 32-channel head coil during a 10 min cognitive task, and will be compared at baseline and week 1 (for full details of this methodology see Yankouskaya A, et al., Biology, 2023, 12, 211.) | Baseline to week 1 |