Peer-modeled Intervention

Theoretical framework The proposed study utilises the Social Cognitive Theory (SCT). The SCT, widely utilised, shows the dynamic interaction among a person's behaviour (skills, practice and self-efficacy), environmental determinants (social norms, influence on others and access in the community), and personal factors (knowledge, expectations and attitudes), and how those factors change or affect one another. The current study targets personal factors and individual behaviours, given their importance, including their changeability and literature-based relevance.

In line with the SCT cognitive factors, the awareness component aims to increase knowledge of cardio-metabolic health and risk factors, health expectancies from behaviour change practices, and attitudes towards body size perception in relation to health.

Physical literacy comprises elements such as motivation and confidence, physical competence, and knowledge and understanding of the value of, and responsibility for, engaging in physical activities for life. Physical literacy aims to increase knowledge and understanding of the health benefits of engaging in daily physical activity as an integral part of one's life choices. This is based on the behavioural factors of skills, practice and self-efficacy of the SCT.

Food literacy is a collection of inter-related knowledge, skills and behaviour required to empower in the five core domains; i) planning for food through making feasible decisions; ii) select of quality food; iii) food preparation of tasty and hygienic meals; iv) and eat food to meet individual needs and v) ability to screen information from different platforms on healthy eating. Food literacy aims to increase knowledge and skills for consuming and preparing healthy meals that improve cardio-metabolic health. The basis to achieve food literacy is the behavioural factors of skills, practice, and self-efficacy within the SCT.

The study's primary objective is to assess the effect of a complex behavioural change intervention on the central adiposity of women of reproductive age.

The secondary objectives include:

* To assess the dietary changes of the women. * To assess the physical activity changes of the women. * To assess the psycho social outcomes of the women. * To identify theory mediators for optimal cardio-metabolic health. * To assess participants' adherence to the intervention. * To assess participants' satisfaction towards the content and the peer modelling strategy. * To assess the delivery accuracy of the intervention content by the peer models.

Study design

The study will be a cluster randomised 2-arm trial. The villages are clusters of distinct community units served by a specific Village Health Team (VHT).

The sample area (Kakoba Ward) comprises 12 villages, randomised into the intervention and comparison groups in a 1:1 ratio.

The study will include an active intervention phase lasting 3 months (12 weeks) and a follow-up post-intervention phase also lasting 3 months (12 weeks), totalling 6 months (24 weeks).

Study setting

The study will be conducted in Mbarara City, located in the Southwestern region of Uganda.

Mbarara City was chosen for the current study because;: i) 27% of the women are diagnosed with overweight or obesity within the region; ii) Behavioural intervention studies have been concentrated in the central region of Uganda, leaving a gap in other regions like the western region; iii) Mbarara City is among the newly made cities in Uganda, thus a given opportunity for a high urbanisation rate and food deserts; iv) Following our cross-sectional study (study reference number HS4708ES), it is imperative to conduct a behaviour change intervention that can optimise the cardio-metabolic health of the women in Mbarara City.

Study participant recruitment

With support from the village health teams, the investigators will advertise the study by distributing flyers with study details within the study area. Interested participants will be screened for eligibility within each cluster. In order to prevent cross-contamination:

* Eligible participants per cluster will not be randomised further. * Clusters will be geographically separated to reduce interactions between participants from different study arms. * Intervention delivery will be conducted at the cluster level through designated peer models who will be trained exclusively for their assigned study arm and instructed not to share material or information with different cluster peer models. * Outcome assessments will be standardised and conducted independently of intervention delivery to minimise bias.

Sample size calculation

The sample size is calculated based on the Rutterford methods for sample size determination in cluster randomised trials. The parameters to consider in the sample calculation are;

* The Z value of 1.96 at a type 1 error of 5% with a power of 80%. * The standard deviation of 15.58 for the mean waist circumference is based on our cross-sectional study (findings yet to be published). * The effect size is 7.4 cm based on the Mediterranean diet for the central obesity study. * The n value is 15 participants per cluster. * The intra-cluster correlation coefficient, r = 0.001, is based on previous studies.

Thus, the sample size is calculated at 70 participants per arm. Considering a 10% attrition rate, 77 participants are required. Hence, the study aims to include 154 WRA in the trial with 77 participants per study arm.

Study delivery

The study will be delivered in 3 phases, i.e.,

1. Phase 1: The selection and training of the peer models that will deliver the intervention. With guidance from the village health teams, the investigators will select a peer model for each cluster. The following are the inclusion criteria of a peer model;

* Female * A balance of married and unmarried * Have at least a secondary education * Be willing to lead a group * Have social credibility and be accepted by the group members * Relatable to the participants regarding their journey on optimising cardio-metabolic health * Are currently practicing behavioural changes regarding dietary and physical activity practices.

The peer models will go through a block of training, with the first session focusing on knowledge and skills in facilitating groups and health education, key cardio-metabolic concepts, measurement using a waist circumference tape measure, and sharing life experiences.

In the second training block, the peer models will share their experiences, points for improvement, and support needs.

There will be enhanced training in the areas they identify as needing more skills and knowledge. 2. Phase 2: Community inauguration This phase will include selecting participants in accordance with the eligibility criteria, followed by a briefing session on the intervention for the partners of married participants or key family heads.

The purpose is to introduce the intervention to increase its acceptability and adherence.

The goal is to enhance social support within the participant's home environment. The activities of this phase are; * The peer models will share their experiences, including the barriers, solutions, and facilitators to changing their lifestyles for optimal cardio-metabolic health. * The peer models will share the infographics with key messages about the study and what is required from the participants. 3. Phase 3: Intervention Participant intervention where both the intervention and comparison arm intervention components will start.

Intervention components

Intervention components will be delivered through a designed toolkit by the peer models in group sessions. The intervention components are;

1. Awareness. This will include the following activities;

* Group discussion session on perceptions of ideal and healthy body sizes, guided by body image silhouettes. * A practical session on waist circumference measurement. * Group discussion on the risk of cardio-metabolic health in relation to waist circumference. * Group discussion to compare the measurements with the earlier discussed body perceptions and body silhouettes. * Group discussion and illustrate doable actions by conducting lifestyle physical activity mapping and food sorting for optimal cardio-metabolic health. * Peer models will share their experience and journey on what they are doing for optimal cardio-metabolic health. 2. Physical literacy This includes the following activities

* Group discussion on physical activity mapping in order to identify the different physical activities as lifestyle and recreational. * Group discussion to differentiate between a sedentary lifestyle, moderate and vigorous physical activities. * Group discussion on barriers to engaging in physical activity. * Group discussions on physical activity and metabolic health based on global recommendations. * Illustration of brisk walking as a proposed lifestyle physical activity. * Weekly goal setting using a designed pluck card. * Pairing of participants within the groups for social support. 3. Food literacy Food literacy will include the following activities;

* Meal planning by emphasising the availability and accessibility of fruits and vegetables in the home environment, with less fatty snacks. * Planning for simple vegetable recipes * Illustrations on budgeting for food. * Group discussion on selecting the different food sources and healthier eating when away from home, especially for retail business women who eat out in restaurants. * Conducting hands-on meal preparation sessions utilising what is accessible to the community under safety and hygiene principles, and exploring different healthy preparation and cooking methods, such as boiling. Therefore, the peer models will hold cooking demonstrations on preparing vegetables, fruits, and lower-fat foods to enhance food preparation skills. * Using the plate model, healthy meal choices and portions will be emphasised. Each Participant will be encouraged to use it for their main meal. The investigators will create a food poster featuring the model plate and typical foods in Mbarara. * Group discussion on screening of relevant information regarding healthy eating within the environment by mapping the information sources, the trusted sources and the relevancy of the information with the guidance of infographic facts.

Intervention and follow-up phases During the active phase, the intervention components will be delivered weekly for the first 12 weeks. During the post-intervention period, there will be no contact between the peer models and the participants for 12 weeks.

Data collection and measurement

First, data will be collected utilising the WHO STEPwise instrument. The instrument consists of three steps.

Step 1: Data on socio-demographic characteristics and lifestyle are collected. * The socio-demographic characteristics include age, education level, marital status, employment status, child-bearing status, household size, religion, ethnic background, household expenditure and residence area. * The lifestyle commodities collected include dietary intake and physical activity.

• Increase in physical activity levels [Срок оценки: Assessment at baseline, endline after 3 months of the intervention and at 6 months post-intervention.]
• Increase in fruit and vegetable intake [Срок оценки: At baseline, 3 months at endline of the active phase of the intervention and at 6 months post-intervention]
• Fasting blood glucose levels [Срок оценки: Measure at baseline, endline after 3 months of the intervention, and post-intervention at 6 months]
• HDL cholesterol [Срок оценки: At baseline, after 3 months of the active phase of the intervention, and at 6 months post-intervention]
• Triglycerides [Срок оценки: At baseline, after 3 months of the active phase of the intervention and at 6 months post-intervention.]
• Blood pressure [Срок оценки: At baseline, after 3 months of the active phase of the intervention and at 6 months post-intervention]
• Fat mass [Срок оценки: At baseline, 3 months after the active phase of the intervention and at 6 months post-intervention]
• Body mass index [Срок оценки: At baseline, 3 months after the active phase of the intervention and at 6 months post-intervention.]
• Arterial stiffness [Срок оценки: At baseline, 3 months after the active phase of the intervention, and at 6 months post-intervention.]
• Food literacy [Срок оценки: At baseline, endline after 3 months of the active phase of the intervention, and at 6 months post-intervention]
• Body size preference [Срок оценки: Assessment at baseline, endline after 3 months of the intervention and at 6 months post-intervention.]
• Body dissatisfaction [Срок оценки: At baseline, 3 months after the active phase of the intervention and at 6 months post-intervention.]