- Changes in waist circumference at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using a tape measure
- Changes in waist circumference after 6-months of the behavioural support programme [ Time Frame: First baseline to 6-months follow-up ]
Assessed using a tape measure
- Changes in fat-free mass at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using bioelectrical impedance analysis (BIA)
- Changes in fat-free mass after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using bioelectrical impedance analysis (BIA)
- Changes in fat mass at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using bioelectrical impedance analysis (BIA)
- Changes in fat mass after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using bioelectrical impedance analysis (BIA)
- Changes in heart rate at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using an oximeter
- Changes in heart rate after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using an oximeter
- Changes in systolic and diastolic blood pressure at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using a sphygmomanometer
- Changes in systolic and diastolic blood pressure after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using a sphygmomanometer
- Changes in comorbidities at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Comorbidities assessed using medical records, physical examination and blood sample analyses
- Changes in Liver function at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Fasted Liver function assessed using blood sample analyses
- Changes in Glucose at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Fasted Glucose assessed using blood sample analyses
- Changes in Lipids at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Fasted Lipids assessed using blood sample analyses
- Changes in HbA1c at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Fasted HbA1c assessed using blood sample analyses
- Changes in C-reactive protein (CRP) at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Fasted CRP assessed using blood sample analyses
- Changes in metabolomics at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Fasted and fed metabolomics assessed using blood sample analyses
- Changes in Comorbidities after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Comorbidities assessed using medical records, physical examination and blood sample analyses
- Changes in Liver function after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Fasted Liver function assessed using blood sample analyses
- Changes in Glucose after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Fasted Glucose assessed using blood sample analyses
- Changes in metabolomics after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Fasted and fed metabolomics assessed using blood sample analyses
- Changes in Lipids after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Fasted Lipids assessed using blood sample analyses
- Changes in HbA1c after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Fasted HbA1c assessed using blood sample analyses
- Changes in C-reactive protein (CRP) after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Fasted CRP assessed using blood sample analyses
- Changes in appetite at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Fasted and fed appetite scores (Visual analogue scale) assessed using a meal test
- Changes in gut hormones at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Fasted and fed circulating gut hormones assessed using a meal test
- Changes in adipocytokines at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Fasted adipocytokines assessed using a meal test
- Changes in appetite after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
(a) Fasted and fed appetite scores (Visual analogue scale, 10 point scale, higher score indicates greater hunger) assessed using a meal test
- Changes in gut hormones after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Fasted and fed circulating gut hormones assessed using a meal test
- Changes in adipocytokines after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Fasted adipocytokines assessed using a meal test
- Changes in sleep at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Change in objectively reported sleep assessed using accelerometry.
- Changes in sleep quality at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Change in subjectively reported sleep assessed using the Pittsburgh Sleep Quality Index
The Pittsburgh Sleep Quality Index is a validated 19-item measure, which will be used to determine sleep quality in the past month, to distinguish between good and poor sleepers. A higher score indicates poorer sleep quality.
- Changes in sleep after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Change in objectively reported sleep assessed using accelerometry.
- Changes in sleep quality after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Change in subjectively reported sleep assessed using the Pittsburgh Sleep Quality Index
The Pittsburgh Sleep Quality Index is a validated 19-item measure, which will be used to determine sleep quality in the past month, to distinguish between good and poor sleepers. A higher score indicates poorer sleep quality.
- Changes in physical activity at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
(a) Change in objectively reported physical activity levels (sedentary, light (LPA), moderate (MPA), vigorous (VPA)) assessed using accelerometry
- Changes in physical activity levels at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Change in subjectively reported physical activity levels (sedentary, light (LPA), moderate (MPA), vigorous (VPA)) assessed using the short form International Physical Activity Questionnaire (IPAQ-SF).
The short-form International Physical Activity Questionnaire (IPAQ-SF) is a standardised questionnaire consisting of 7 questions that ask about physical activity in the past 7 days. IPAQ-SF will be used to subjectively assess time spent in light, moderate and vigorous physical activity levels, and time spent sitting. The questionnaire takes a few minutes to complete. Higher physical activity values indicate greater physical activity levels, higher time spent sitting indicates greater sedentary behaviour.
- Changes in physical activity after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
(a) Change in objectively reported physical activity levels (sedentary, light (LPA), moderate (MPA), vigorous (VPA)) assessed using accelerometry
- Changes in physical activity levels after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Change in subjectively reported physical activity levels (sedentary, light (LPA), moderate (MPA), vigorous (VPA)) assessed using the short form International Physical Activity Questionnaire (IPAQ-SF).
The short-form International Physical Activity Questionnaire (IPAQ-SF) is a standardised questionnaire consisting of 7 questions that ask about physical activity in the past 7 days. IPAQ-SF will be used to subjectively assess time spent in light, moderate and vigorous physical activity levels, and time spent sitting. The questionnaire takes a few minutes to complete. Higher physical activity values indicate greater physical activity levels, higher time spent sitting indicates greater sedentary behaviour.
- Changes in handgrip strength at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using a hand dynamometer.
- Changes in handgrip strength after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using a hand dynamometer.
- Changes in walking distance at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using the 6-minute walk test (6MWT)
- Changes in changes in walking distance after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using the 6-minute walk test (6MWT)
- Changes in leg strength at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using the sit-to-stand (STS) test
- Changes in leg strength after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using the sit-to-stand (STS) test
- Changes in quality of life at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using EuroQoL 5 dimensions 3 levels (EQ-5D-3L)
EQ-5D-3L is a 6-item self-reported questionnaire that consists of a descriptive system to assess the following 5 domains: mobility, self-care, usual activities, pain/discomfort and anxiety/depression using 3 levels (e.g. mobility: I have no problems walking about, I have some problems walking about, or I am confined to bed, higher score indicates worse quality of life) and a visual analogue scale, which records self-rated health on a 0 to 100 scale (100 = best health).
- Changes in quality of life after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using EuroQoL 5 dimensions 3 levels (EQ-5D-3L)
EQ-5D-3L is a 6-item self-reported questionnaire that consists of a descriptive system to assess the following 5 domains: mobility, self-care, usual activities, pain/discomfort and anxiety/depression using 3 levels (e.g. mobility: I have no problems walking about, I have some problems walking about, or I am confined to bed, higher score indicates worse quality of life) and a visual analogue scale, which records self-rated health on a 0 to 100 scale (100 = best health).
- Changes in weight-related quality of life at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using Impact of Weight on Quality of Life-Lite (IWQOL-Lite)
Impact of Weight on Quality of Life-Lite (IWQOL-Lite) is a 31-item, self-reported, obesity and overweight-specific measure of health-related quality of life. This tool consists of a total score, scoring on five aspects - physical function, self-esteem, sexual life, public distress, and work. Higher scores indicate a better quality of life.
- Changes in weight-related quality of life after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using Impact of Weight on Quality of Life-Lite (IWQOL-Lite)
Impact of Weight on Quality of Life-Lite (IWQOL-Lite) is a 31-item, self-reported, obesity and overweight-specific measure of health-related quality of life. This tool consists of a total score, scoring on five aspects - physical function, self-esteem, sexual life, public distress, and work. Higher scores indicate a better quality of life.
- Changes in mental wellbeing at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS)
The Warwick Edinburgh Mental Wellbeing Scale (WEMWBS) is a 14-item, positively worded, validated measure of mental wellbeing, with 5 responses, which are summed to produce a single measure of wellbeing. Scores range from 14 to 70, with higher scores indicating greater positive mental wellbeing.
- Changes in mental wellbeing after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using Warwick-Edinburgh Mental Wellbeing Scale (WEMWBS)
The Warwick Edinburgh Mental Wellbeing Scale (WEMWBS) is a 14-item, positively worded, validated measure of mental wellbeing, with 5 responses, which are summed to produce a single measure of wellbeing. Scores range from 14 to 70, with higher scores indicating greater positive mental wellbeing.
- Changes in depression at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using Patient Health Questionnaire-9 (PHQ-9)
The Patient Health Questionnaire (PHQ-9) is a 9-item validated measure, which will be used to assess the severity of depression. Each item is rated from 0 to 3, for a total score out of 27. A score of 15-19 indicates moderately severe depression, and 20-27 indicates severe depression.
- Changes in depression after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using Patient Health Questionnaire-9 (PHQ-9)
The Patient Health Questionnaire (PHQ-9) is a 9-item validated measure, which will be used to assess the severity of depression. Each item is rated from 0 to 3, for a total score out of 27. A score of 15-19 indicates moderately severe depression, and 20-27 indicates severe depression.
- Changes in anxiety at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using Generalised Anxiety Disorder Assessment-7 (GAD-7)
The Generalised Anxiety Disorder assessment (GAD-7) is a 7-item anxiety scale, which will be used to screen and measure the severity of generalised anxiety disorder. Each item is rated from 0 to 3, for a total score out of 21. A score of 11-15 indicates moderately severe anxiety, and 16-21 of severe anxiety.
- Changes in anxiety after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using Generalised Anxiety Disorder Assessment-7 (GAD-7)
The Generalised Anxiety Disorder assessment (GAD-7) is a 7-item anxiety scale, which will be used to screen and measure the severity of generalised anxiety disorder. Each item is rated from 0 to 3, for a total score out of 21. A score of 11-15 indicates moderately severe anxiety, and 16-21 of severe anxiety.
- Changes in eating behaviour (psychological impact of living in food-abundant environments) at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using Power of Food scale
The Power of Food (PoF) scale is a 15-item validated measure, which will be used to assess the psychological impact of living in food-abundant environments. Higher scores indicate greater psychological impact of living in a food-abundant environment
- Changes in eating behaviour (psychological impact of living in food-abundant environments), after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using Power of Food scale
The Power of Food (PoF) scale is a 15-item validated measure, which will be used to assess the psychological impact of living in food-abundant environments. Higher scores indicate greater psychological impact of living in a food-abundant environment
- Changes in eating behaviour (severity and type of food cravings) at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using Control of Eating Questionnaire
The Control of Eating Questionnaire (CoEQ) is a 21-item validated measure, which will be used to measure the severity and type of food cravings. Higher scores indicate greater agreement with the statement (severity and type of food cravings)
- Changes in eating behaviour (severity and type of food cravings), after 6-months of the behavioural support [ Time Frame: First baseline to 6-months follow-up ]
Assessed using Control of Eating Questionnaire
The Control of Eating Questionnaire (CoEQ) is a 21-item validated measure, which will be used to measure the severity and type of food cravings. Higher scores indicate greater agreement with the statement (severity and type of food cravings)
- (In a subset of participants) Changes in brain functional resting state connectivity at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Assessed using functional brain magnetic resonance imaging and diffusion weighted imaging.
- (In a subset of participants) Changes in brain functional resting state metabolism at 8 weeks between Diet A and Diet B [ Time Frame: Baseline to 8 weeks for both diets ]
Metabolite changes assessed using magnetic resonance spectroscopy.
- Changes in aspects of behaviour regulation after 6-months of the behavioural support programme [ Time Frame: First baseline to 6-months follow-up (49 weeks) ]
(a) Barriers and facilitators to healthy eating and physical activity, assessed using a capability, opportunity, motivation - behaviour (COM-B) questionnaire
Participants will complete one questionnaire investigating the barriers and facilitators to physical activity and healthy eating, based on the COM-B model of behaviour change. The survey contains 257 items; the physical activity component contains 137 items, and the eating component contains 120 items.This survey is expected to take 30 minutes. The survey uses a range of items (Likert scale, yes/no, agree/disagree, true/false) with levels of agreement yes/no indicating barriers or facilitators to behaviour.
- Barriers and facilitators to eating a healthy, balanced diet [ Time Frame: 6-months follow-up ]
Assessed using a one to one semi-structured telephone/video call interview at 6-months follow-up
The aim of the qualitative interviews is to gain an in-depth understanding of the barriers and facilitators to adherence to a minimally processed diet, and to map these onto an intervention development framework. Interviews will follow a simple topic guide designed to explore motivations for participating and experiences of the trial, with a particular focus on barriers and facilitators to adhering to a minimally processed diet.
The qualitative process will use Framework Analysis and other methods of thematic analysis designed to explore experiences of a behaviour change trials.
- Changes in diet after 6-months of the behavioural support programme [ Time Frame: First baseline to 6-months follow-up ]
(a) Changes in food and nutrient intake, assessed using 24-hour recall (Intake24)
24-hour recalls will be conducted using Intake24, a validated, online, self-reported dietary recall system, based on a multiple-pass 24-hour recall that is suitable for the general population (https://intake24.co.uk). The recall takes on average 12 minutes to complete58. The system is self-completed and will guide the participant through the recall process. Firstly, the user will list all food and drink consumed, followed by probing questions about quantity consumed and further information on food and drink reported.
- Changes in habitual diet after 6-months of the behavioural support programme [ Time Frame: First baseline to 6-months follow-up ]
(a) Changes in food and nutrient intake, assessed using food frequency questionnaire (FFQ) (European Prospective Investigation of Cancer (EPIC)-Norfolk FFQ)
Food frequency questionnaires can be used to determine average food intakes over longer durations of time. Average food intakes will be assessed using the European Prospective Investigation into Cancer and Nutrition (EPIC)-Norfolk FFQ, a validated, semi-quantitative measure of average dietary intake over the past year.
The EPIC-Norfolk FFQ is split into two sections, part 1 contains a 130-item food list. Each item contains an individual food, combination of individual foods or a food type. Participants tick the most appropriate frequency of consumption of that food item from nine options (from never or less than once per month, to 6+ per day). Part 2 asks more detailed questions relating to the food items in part 1, including types of fats used in cooking, types of milks consumed and choice of cereals.
- Changes in weekly food shopping expenditure at 6-months follow-up will be compared with the first baseline, based on changes in reported dietary intakes [ Time Frame: First baseline to 6-months follow-up ]
Assessed using 24-hour recall (Intake24)
24-hour recalls will be conducted using Intake24, a validated, online, self-reported dietary recall system, based on a multiple-pass 24-hour recall that is suitable for the general population (https://intake24.co.uk). The recall takes on average 12 minutes to complete58. The system is self-completed and will guide the participant through the recall process. Firstly, the user will list all food and drink consumed, followed by probing questions about quantity consumed and further information on food and drink reported.