Diet-Induced Variability in Appetite (DIVA)

Study Overview
=================
Brief Summary
-----------------
The aim of this study is to test the hypothesis that dietary weight loss (WL) through alternate day fasting (ADF) will enhance appetite control, health markers and wellbeing following WL compared to standard daily calorie restriction (CR).

Detailed Description
-----------------
This is a proof of concept randomized controlled trial in which overweight/obese females will be randomised to a dietary weight loss intervention (ADF or CR) to achieve ≥5% WL. Behavioural measures of appetite control including ad libitum intake after a fixed meal, body composition, resting metabolic rate, measured physical activity and daily energy expenditure, sleep quality, hedonic food reward and eating behaviour traits will be assessed before, during and after the WL intervention in those who reach the target weight loss within 12 weeks. After weight loss phase, participants will be given standard healthy eating and physical activity advice for weight maintenance and body weight will be followed up after weight loss at 12 months.

Official Title
-----------------
The Impact of Weight Loss Through Alternate Day Fasting on Homeostatic and Hedonic Appetite Control and Eating Behaviour: a Proof of Concept Randomized Controlled Trial

Conditions
-----------------
Overweight and Obesity

Intervention / Treatment
-----------------
* Behavioral: Alternate Day Fasting
* Behavioral: Continuous dietary restriction


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Female participants aged between 18 and 55 years at the time of signing informed consent BMI of 25.0 - 34.9 kg/m2 Exclusion Criteria: Significant health problems which in the opinion of the investigator, might jeopardise participant's safety or compliance with the protocol Currently enrolled in a weight loss programme or following a specific diet plan. History of eating disorders including binge eating. Taking any medication or supplements known to affect appetite or weight within the past month and/or during the study Pregnant, planning to become pregnant or breastfeeding History of anaphylaxis to food Known food allergies or food intolerance Smokers and those who have recently ceased smoking (< 6 months) BMI < 24.9 kg/m2 or > 35 kg/m2 Volunteers having lost significant amount of weight in the previous 6 months (± 4kg) Volunteers who exercise > 3 days per week or have significantly changed their physical activity patterns in the past 6 months or who intend to change them during the study Participants receiving systemic or local treatment likely to interfere with evaluation of the study parameters Participants who work in appetite or feeding related areas. Participants who do shift work

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 55 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Alternate day fasting<br>Participants randomised to Alternate Day Fasting weight loss intervention. One day fasting of 25% total energy requirements alternated with one day ad libitum intake until study completion at >/=5% weight loss which is an average of 12 weeks. | Behavioral: Alternate Day Fasting<br>* 25% daily energy requirements every other day until study completion at >/=5% weight loss which is an average of 12 weeks.<br>|
| Active Comparator: Continuous caloric restriction<br>Participants randomised to continuous caloric restriction weight loss intervention. Every day intake of 75% total energy requirements until study completion at >/=5% weight loss which is an average of 12 weeks. | Behavioral: Continuous dietary restriction<br>* 25% daily energy requirements every other day until study completion at >/=5% weight loss which is an average of 12 weeks.<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in energy intake from ad libitum lunch | Measured changes in ad-libitum energy intake following consumption of formulated test meal in comparison to control | week 0, week 3 and at study completion, an average of 12 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Visual Analogue Scale (VAS) ratings of appetite | Change in ratings of hunger, satiety, fullness and prospective food consumption before, after and between meals. Scale range is minimum 0 to maximum 100mm. A composite appetite score will be calculated from the average of scores on hunger, satiety, fullness and prospective food consumption scales. A higher score is considered a worse outcome. | week 0, week 3 and at study completion, an average of 12 weeks | 
| Change in Control of Eating Questionnaire (CoEQ) scale scores | 21-item scale; subscales are average of relevant items; subscales are computed for dimensions of Craving Control, Craving for Savoury, Craving for Sweet, Positive Mood; minimum subscale score = 0, maximum subscale score = 100; higher values are better outcome for Craving Control and Positive Mood subscales; lower values are better outcome for Craving for Sweet and Craving for Savoury subscales. | week 0, week 3 and at study completion, an average of 12 weeks | 
| Change in explicit liking of food from Leeds Food Preference Questionnaire | Leeds Food Preference Questionnaire is a computer-based task with subscales scores for the 4 food categories high fat and sweet, high fat and non-sweet, low fat and sweet and low fat and non-sweet (minimum score = 0, maximum score = 100), Higher values for high fat food categories relative to low fat food categories considered worse outcome. | week 0, week 3 and at study completion, an average of 12 weeks | 
| Change in explicit wanting of food from Leeds Food Preference Questionnaire scores | Leeds Food Preference Questionnaire is a computer-based task with subscales scores for the 4 food categories high fat and sweet, high fat and non-sweet, low fat and sweet and low fat and non-sweet (minimum score = 0, maximum score = 100), Higher values for high fat food categories relative to low fat food categories considered worse outcome. | week 0, week 3 and at study completion, an average of 12 weeks | 
| Change in relative preference of food from Leeds Food Preference Questionnaire scores | Leeds Food Preference Questionnaire is a computer-based task with subscales scores for the 4 food categories high fat and sweet, high fat and non-sweet, low fat and sweet and low fat and non-sweet (minimum score = 0, maximum score = 48), Higher values for high fat food categories relative to low fat food categories considered worse outcome. | week 0, week 3 and at study completion, an average of 12 weeks | 
| Change in implicit wanting of food from Leeds Food Preference Questionnaire scores | Leeds Food Preference Questionnaire is a computer-based task with subscales scores for the 4 food categories high fat and sweet, high fat and non-sweet, low fat and sweet and low fat and non-sweet (minimum score = -100, maximum score = 100), Higher values for high fat food categories relative to low fat food categories considered worse outcome. | week 0, week 3 and at study completion, an average of 12 weeks | 
| Change in VAS rating of palatability post lunch | Change in ratings of pleasantness, desire to eat more and palatability after the lunch test meal | week 0, week 3 and at study completion, an average of 12 weeks | 
| Change in fat mass | Change in fat mass from iDXA/BodPod | week 0, week 3 and at study completion, an average of 12 weeks | 
| Change in fat free mass | Change in fat free mass from iDXA/BodPod | week 0, week 3 and at study completion, an average of 12 weeks | 
| Change in resting metabolic rate | Change in resting metabolic rate from indirect calorimetry | week 0, week 3 and at study completion, an average of 12 weeks | 
| Change in free-living physical activity | Change in 7-day free-living physical activity from SenseWear Armband | week 0, week 3 and at study completion, an average of 12 weeks |