Article Text

Original research
Feasibility of a peer-supported, WhatsApp-assisted, lifestyle modification intervention for weight reduction among adults in an urban slum of Karachi, Pakistan: a mixed-methods, single-group, pretest–post-test, quasi-experimental study
  1. Sabahat Naz1,
  2. Kaniz Amna Haider2,
  3. Ali Jaffar2,
  4. Umber Khan1,
  5. Iqbal Azam1,
  6. Amna Rehana Siddiqui1,
  7. Romaina Iqbal3
  1. 1Community Health Sciences Department, The Aga Khan University, Karachi, Pakistan
  2. 2Pediatrics and Child Health, The Aga Khan University, Karachi, Pakistan
  3. 3Department of Community Health Sciences and Medicine, The Aga Khan University, Karachi, Pakistan
  1. Correspondence to Romaina Iqbal; romaina.iqbal{at}


Objectives This pilot study assessed whether a peer-supported, WhatsApp-assisted lifestyle modification intervention for weight reduction is feasible to execute a definitive trial.

Design A mixed-methods, single group, pretest and post-test, quasi-experimental study.

Setting Azam Basti, an urban slum in Karachi, Pakistan.

Participants Fifty participants (males and females aged 20–60) with a body mass index of >23 kg/m2, along with their nominated peers from the same family.

Intervention Using motivational interviewing techniques, a trained nutritionist delivered the lifestyle modification intervention to the participants and peers for 3 days after the baseline assessment and then once monthly for 1 year. The intervention was delivered in groups using WhatsApp voice calls. The education sessions mainly focused on dietary modifications, physical activity advice and peer-support assignments to achieve a 5% wt loss from the participant’s initial body weight.

Outcomes The feasibility measures included screening, recruitment, retention and monthly interview response rates. At 1 year, in-depth interviews (IDIs) with participants and peers were conducted to explore the facilitators, barriers, acceptability and experiences of the intervention. Changes in weight, calorie intake/day and calorie expenditure/day were also assessed.

Results The recruitment and retention rates were 32% (n=50/156) and 78% (n=39/50), respectively, while the response rate for monthly interviews ranged between 66% (n=33) and 94% (n=47). The mean weight loss at 1 year was 2.2 kg, and the reduction in mean calorie intake was 386 kcal/day. There were no changes in the mean calorie expenditure. During the IDIs, participants and peers reported intervention via WhatsApp and peer support as convenient, flexible and supportive.

Conclusions The quantitative and qualitative findings of the current pilot study support the scale-up of this work with minor modifications to the screening method as well as close monitoring and motivational interviewing to improve adherence in terms of physical activity.

Trial registration number NCT05928338.


Data availability statement

Data are available upon reasonable request.

This is an open access article distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited, appropriate credit is given, any changes made indicated, and the use is non-commercial. See:

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Strengths and limitations of this study

  • Our study was conducted in a slum setting, which is appropriate with respect to the target population for the intervention.

  • We used a participant-nominated peer-support approach to improve adherence to a lifestyle modification.

  • We used an efficient method for delivering lifestyle modification education to the participants and peers via WhatsApp, making it convenient and easily accessible.

  • We used a single-group, pretest and post-test design for pragmatic reasons, and the absence of a comparison group is an important limitation of the study.


Obesity affects about one-third of the world’s adult population.1 According to the WHO, the global burden of adults with overweight has reached 1.9 billion, and more than 650 million are obese.1 Furthermore, it is also estimated that obesity causes 3.9% of years of life lost and 3.8% of disability-adjusted life years and accounts for 4 million deaths globally.2 3 More than 60% of the world’s obese population belongs to developing countries, including Pakistan.4 The National Nutrition Survey of Pakistan reported a 9.8% increase in the prevalence of overweight/obesity among females in 2018 (37.8%) as compared with 2011 (28%).5 6 Besides, people living in urban areas have a higher prevalence of obesity (56% of males and 67% of females) than in rural.7 8

The impact of obesity is more on morbidity than mortality, causing health impairment and reduced quality of life.9 10 People with obesity face inequalities in daily life opportunities, are highly stigmatised and become socially isolated.11 12 In addition, people with obesity suffer from psychological conditions such as anxiety and depression due to social negligence and lack of support.13 Besides, obesity also contributes to non-communicable diseases such as type 2 diabetes mellitus, cardiovascular diseases, high blood pressure and other metabolic issues.9 14 The cost associated with the acute and long-term complications of obesity imposes an enormous economic burden on the individual, their families, society and healthcare systems.15–17

The obesity epidemic results from a complex interaction between genetic, environmental and behavioural factors, which can be modifiable or non-modifiable.18 Non-modifiable risk factors are age, gender, ethnicity, genetic predisposition and socioeconomic status.18 Modifiable risk factors such as dietary patterns, physical activity levels, smoking habits, alcohol consumption, sleep quality and duration and levels of psychological stress are the key risk factors of obesity.18 19 A study conducted in Pakistan, India, Nepal and Sri Lanka found lower intake of fruits and vegetables, higher intake of fast food and soft drinks and watching television being the most prevalent risk factors among people with overweight and obesity.20 In addition, another study from Pakistan found a higher proportion of people with obesity (73%, n=254) with physical inactivity due to spending most of their time using computers and mobile phones and watching television.21

The slums usually have poor housing and inadequate healthcare facilities.22 Moreover, the population in slums faces a higher burden of obesity due to unhealthy diets and physical inactivity.23 Consumption of high-calorie food in slums is higher as it is readily available and cheaper than healthy food.24 25 In addition, limited space, cultural aspects and other safety concerns are the most common reasons for physical inactivity.24 25

Obesity primarily results from energy imbalance, reflecting a person’s excessive dietary intake and reduced energy expenditure.26 Therefore, lifestyle modification is vital in weight reduction and maintenance.27 28 Many lifestyle modification programmes have used digital interventions such as mobile and web-based applications, text message reminders and fitbit devices, with or without the support of healthcare professionals.29–32 Other literature also highlights the role of wearable technology, computers and mobile phone in combating sedentary behaviours.33 Still, lifestyle modification and weight reduction adherence remain challenging.34 35 One limitation of such lifestyle modification programmes is the absence of social support and lack of motivation.36 37 Involvement of social support from family, friends, relatives and neighbours may improve lifestyle modification adherence and increase the programme’s effectiveness.38 39 Peer support is an approach that has worked to help family members, friends or neighbours to improve health and prevent diseases.40 Literature from the West supports the role of peers in the management of various conditions, such as improving long-term cardiovascular risk among hypertensive people,40 managing type 2 diabetes41 and helping prevent and care for people with HIV.42 In addition, other studies also highlighted the role of social support in weight loss-related behaviour interventions; however, they were conducted in the West.43 44 Therefore, this pilot study assessed whether a peer-supported, WhatsApp-assisted lifestyle modification intervention for weight reduction is feasible to execute a definitive trial.

Study aims

  1. To assess the feasibility of screening, recruitment, retention and monthly-interview response rates in a peer-supported, WhatsApp-assisted lifestyle modification intervention for weight reduction among adults in an urban slum of Karachi, Pakistan

  2. To explore barriers, facilitators, acceptability and experience of a peer-supported, WhatsApp-assisted lifestyle modification intervention for weight reduction among adults in an urban slum of Karachi, Pakistan

  3. To identify the trends of change in weight, calorie intake and calorie expenditure in a peer-supported, WhatsApp-assisted lifestyle modification intervention for weight reduction among adults in an urban slum of Karachi, Pakistan.


Study design and setting

This study was a mixed-methods, single group, pretest–post-test, quasi-experimental feasibility study integrated with qualitative interviews conducted at the end of the study (after 1 year) with study participants and peers.

The study site was Azam Basti, an urban slum in Karachi with poor literacy levels and a lack of access to healthcare facilities.45 People residing in Azam Basti belong to low-income and middle-income families.46 The enrolment commenced on 15 July 2020, and participants were followed for 1 year till 30 September 2021.

Impact of the COVID-19 pandemic on the study

This study was initially designed to be delivered in person in the community. However, earlier in 2020, the COVID-19 pandemic was declared, and a nationwide lockdown was announced and strictly followed that limits in-person contact and field activities. According to these pandemic situations, amendments to the study have been made and approved by the respective ethical review committee of the institution. The modifications included telephonic contact for the screening of study participants, an online intervention delivered using WhatsApp and flexibility of telephonic interviews at baseline and during the follow-up visits until the COVID restrictions were relaxed. Hence, it became a hybrid study from an interaction perspective with the participants and relied heavily on WhatsApp for intervention delivery.

Participant recruitment

This study was nested in an ongoing research project in Azam Basti, showing 29% overweight and 42% obesity prevalence among study subjects (unpublished work). Using a household listing from this study, data collectors contacted the households via phone, provided study details and performed initial screening. The household list was used in sequence to assess the initial eligibility of any one family member of the household until we enrolled 50 participants. Households were contacted in the morning; if no response to the phone calls was found, the second attempt was made in the afternoon. Eligibility for initial screening (via phone) included males and females aged 20–60 years, who had access to smartphones and an internet connection, agreed to nominate one peer from their family and provided written informed consent. Those with pregnancy, chronic conditions, disability and other health-related issues that require special treatment and dietary and physical activity restrictions were excluded. Potential participants who met the initial screening criteria via phone were visited to assess their eligibility in terms of body mass index (BMI) (>23 kg/m2). Height was measured in centimetres (cm) and weight in kilograms (kg) using a digital weighing scale (HT-2003A). Both values were entered into the web-based calculator to calculate BMI.47 Participants with a BMI of >23 kg/m2 were enrolled in the study. Written informed consent was obtained from the participants during this community visit.

Peer recruitment

The participants were requested to nominate one peer from their family. The peer eligibility included males and females, aged >20 years, willing to attend online training sessions, agreed to help participants with lifestyle modification adherence throughout the study period and provided written informed consent. Study details were provided to the peers, and eligibility was assessed. Those who met eligibility criteria were enrolled, and written consent was obtained.

Baseline assessment

Once the participants and peers were enrolled in the study, the baseline assessments were conducted. Height and weight were measured during the field visit, and an interview for sociodemographic and health-related information, 24-hour dietary recall and Global Physical Activity Questionnaire (GPAQ) was conducted over the phone or in person48 (online supplemental table 1). Peers were also interviewed for sociodemographic information at baseline.

Peer-supported, WhatsApp-assisted lifestyle modification intervention

Formation of WhatsApp groups

After the baseline assessments, the data collectors contacted the study participants and their peers to identify a suitable time for online training via WhatsApp. Twelve WhatsApp groups were formed, with three to four participants and their peers in each group. A few participants (about three) and their peers requested individualised WhatsApp training due to timing issues and personal concerns. Almost all participants and peers attended the initial 3 days of training and monthly refreshing session. In case any participant or peer missed any session, they were provided a detailed overview of the session once they became available.


The lifestyle modification intervention, supported by peers, was designed to assist participants in making dietary modifications, increasing physical activity levels and achieving a weight loss target of 5% of their initial body weight while avoiding weight gain. Using motivational interviewing techniques,49 a trained nutritionist delivered online education sessions on lifestyle modification to the participants and peers. The education was provided in the local language (Urdu) using WhatsApp voice calls. The intervention was delivered individually or in groups (mostly) based on the participant’s and peer’s availability and convenience. The sessions covered six lessons related to lifestyle modification and peer support. Two sessions were conducted each day for 1 hour (each session consisted of 30 min) for three consecutive days, followed by a monthly refresher session. The education sessions mainly focused on dietary modifications using food groups and the MyPlate concept, portion size control, effective cooking methods and food exchange options, 30 min of moderate-intensity walking and home-based exercises and safety measures, goal setting and action plans, behaviour-changing strategies, addressing negative thoughts and peer assignments which involved exploring ways to support, encourage and motivate participants to perform planned activities. The peers were primarily responsible for engaging participants in lifestyle modification and providing support, encouragement and motivation for a healthy diet and regular physical activity for weight reduction. A detailed outline of the intervention components has been provided in online supplemental table 2. The participants were provided with a copy of the intervention materials with visual demonstrations to help them follow the instructions during training sessions and for future use. The training was completed within 1 week after the enrolment.

Monthly refresher sessions

A trained nutritionist also delivered once-monthly refresher sessions to the participants and peers on the same WhatsApp groups for 1 year. During the refresher sessions, the participants and peers had the opportunity to discuss compliance and difficulties in following the lifestyle modification plan. By addressing these challenges, participants and peers received guidance from the nutritionist to overcome obstacles and stay on track with their lifestyle modification plan.

Assessment of adherence to the intervention

The data collectors maintained weekly log sheets by contacting participants via phone. They collected information on participant’s dietary and physical activity routines and the extent of support and reminders received from their peers. The information gathered during these phone calls ensured continuous monitoring of the intervention adherence by study participants and peers. With the help of this insightful information, the content of the monthly refresher sessions was modified to improve participant compliance and enhance participant–peer interactions.

Follow-up and endline visits

Study follow-up visits were carried out once monthly for 1 year. These visits involved measuring participant’s weight and administering a 24-hour dietary recall and GPAQ. Additionally, a Social Support Questionnaire (SSQ) was administered quarterly for 1 year. The end of the study visit was conducted at 1 year, during which a 24-hour dietary recall, GPAQ and SSQ were administered. The participant’s weight was also recorded (refer to online supplemental table 1).

Qualitative methods

At the end of the study (1 year), the participants and peers were invited to participate in the qualitative part of the study (refer to online supplemental table 1). Details were provided, and consent was obtained before the interview. Out of the 39 participants who completed their year-long intervention, five participants and four peers were interviewed. A trained independent interviewer conducted the in-depth interviews (IDIs) using an interview guide. The participant’s interview guide included questions about the factors influencing participation, retention and adherence to the lifestyle modification programme to identify barriers, facilitators, acceptability and online training experience. The peer interview guide included questions about the reasons for participating as a peer, factors that helped engage participants, difficulties in engaging participants and their online training experience.

Study data collection tools

24-hour dietary recall

Detailed information on participant’s food intake and portion sizes was collected using a 24-hour dietary recall. A colored-printed food item booklet was provided to the participants to report the portion sizes accurately. A stepwise multiple-pass method was used to improve dietary recall.50 These dietary interviews were carried out once at baseline (before intervention) and once monthly for 1 year (refer to online supplemental table 1). Weekdays and weekends were included in the recall.

These dietary recalls were converted into calories and macronutrients (carbohydrates, protein and fats). The nutritional value of recipes was taken from three primary data sources: the food composition table for Bangladesh, the Indian food composition tables and the US Department of Agriculture.51–53 Change in mean calorie intake over time (from baseline to 12 months) among study participants was reported.

Global Physical Activity Questionnaire (GPAQ)

Physical activity was assessed through the GPAQ developed by WHO.48 The information was collected mainly in three domains, including ‘Activity at work’, ‘Travel to and from places’ and ‘Recreational activities’. GPAQ was administered once at baseline (before intervention) and once monthly for 1 year (refer to online supplemental table 1). Total calorie expenditure was estimated from GPAQ using a standard algorithm and change in mean calorie expenditure was reported among study participants over time (from baseline to 12 months).

Social Support Questionnaire (SSQ)

To assess the role of peers, an SSQ was administered with participants quarterly, that is, 3, 6, 9 and 12 months (refer to online supplemental table 1). Social support was assessed in two domains: encouragement for diet and physical activity, and discouragement for diet and physical activity. The responses were recorded using a 5-point Likert scale, one being ‘almost never’ to five ‘almost always’. The responses were presented as mean±SD.54

Sample size

This pilot study aimed to evaluate the feasibility of the intervention; therefore, the sample size has not been calculated. Instead, based on the recommendations by Julious et al and Lewis et al, a sample size of 50 participants, along with 50 peers, was used for the current pilot work.55 56 The findings of this study will be helpful in the development, sample size estimation and execution of a definitive trial.

Quantitative data analysis

Descriptive analysis of participant’s and peer’s demographic and baseline characteristics was presented as mean±SD, median and IQR and frequencies with percentages as appropriate. The rate of recruitment, retention and monthly interview responses were calculated. The responses of SSQ were presented as mean±SD. A graphical presentation of changes in mean weight, mean calorie intake/day and mean calorie expenditure/day was presented over 1 year. Data were analysed using STATA (V.14.2 StataCorp, Texas, USA).

Qualitative data analysis

We analysed the qualitative data using the manual Thematic Analysis approach.57 All interviews were recorded, and identifiable information was removed during the transcriptions. The interviews were transcribed verbatim into Roman Urdu by the investigators. The quotes used in the paper were translated into English. The data were coded and organised thematically using Excel. Two members examined the codes independently, then matched and organised them into macro themes. After discussion with the study team, the macro themes were finalised and defined with corresponding micro themes.

Patient and public involvement



Quantitative findings

Characteristics of study participants

Out of the 50 participants enrolled in the study, 42 (84%) were females with a mean age of 36±8.9 years. Forty-eight per cent (n=24) had intermediate and higher education, and 66% (n=33) did not work. While comparing the health-related characteristics of the participants at baseline, the mean weight was 80.6±15.9 kg, the mean calorie intake was 1294±283 kcal/day and the mean calorie expenditure was 145±162 kcal/day. The main source of daily calories came from fat (130±71 g), followed by carbohydrates (102±86 g) and protein (46±38 g) (table 1).

Table 1

Baseline characteristics

Peer characteristics

Among the peers, 62% (n=31) were females with a mean age of 35.9±12 years. Fifty-eight per cent (n=29) had intermediate and above education, and 54% (n=27) were working (table 1). The relationship of peers with study participants included 42% (n=21) spouses, 28% (n=14) children, 14% (n=7) mothers and 16% (n=8) other relatives (refer to online supplemental figure 1).

Feasibility of screening participants through phone calls

Out of the 250 households contacted, the response rate was 62.4% (n=156/250). Among those who responded, 23.7% (n=37/156) did not meet the eligibility criteria, 16.7% (n=26/156) refused to participate and 27.6% (n=43/156) migrated from the study catchment area (refer to figure 1).

Figure 1

Participant screening, enrolment and follow-up.

Recruitment, retention and monthly-interview response rates

Our study’s recruitment rate was 32% (n=50/156). Out of the 50 participants enrolled, 78% (n=39/50) completed a year-long study, 18% were lost to follow-up (n=9/50) and 4% (n=2/50) were excluded due to road traffic injury and pregnancy (refer to figure 1).

The response rate for monthly interviews was 82% (n=41) during the first 6 months of the study; however, it decreased to 72% (n=36) at 9 months and 78% (n=39) at 1 year (refer to online supplemental table 3).

Social support from peers for diet and physical activity

The overall mean scores for diet encouragement showed that participants received continuous support for diet throughout the study, whereas the support decreased with time for physical activity encouragement. However, participants did not receive any discouragement, punishments or rewards for following a healthy diet and physical activity plan (table 2). The mean scores were mainly higher for ‘encouraged and reminded them not to eat high-salt/high-fat foods’, ‘discussed their eating habit changes’ and asked for ideas about healthier diets’ in the diet encouragement questions, while for physical activity, the mean scores were higher for ‘sticking with their exercise programme’ and ‘giving helpful reminders for exercise’ (refer to online supplemental table 4).

Table 2

Social Support Questionnaire

Changes in weight, calorie intake and calorie expenditure over 1 year

The mean weight gradually decreased (2 kg reduction) from baseline (80.7 kg) to 6 months (78.7 kg), with a noticeable decline seen at 9 months (76 kg; −4.7 kg). The mean weight reduction was −2.2 kg from baseline (80.7 kg) to 12 months (78.5 kg). In addition, a remarkable decrease in mean calorie intake/day was seen throughout the study period from 1294 kcal/day at baseline to 905 kcal/day at 1 year (−386 kcal/day reduction). However, a substantial increase in mean calorie expenditure/day (+455 kcal/day) was only seen at a 3 month follow-up (online supplemental figure 2).

Qualitative findings

Findings from participants

Five themes emerged from the IDIs: reasons for participation, adherence to lifestyle modification, continuing participation, barriers to adopting a healthy lifestyle and online training experience. Figure 2 summarises the main themes with their sub-themes.

Figure 2

Themes and subthemes (participants).

Reasons for participation

Participants were interested in reducing their weight as they faced difficulties in their daily routines. They mentioned feeling stressed due to weight gain and took part in this study to reduce weight.

I am overweight, and because of this, I can't go out of the house or do any work. That’s why I took part in this study so that I can reduce my weight. (Participant 001)

The mode of delivering intervention was convenient for the participants, especially during the COVID-19 pandemic.

Actually, I wanted to reduce my weight which is why I'm interested [in this program]. Then you called me on WhatsApp, and I had the option to reduce as much as possible while staying at home, and if I joined a gym, I might have to go outside. That’s why I took part in this research. (Participant 014)

Other reasons for participation include interest in gaining knowledge that helps stay healthy and fear of developing other problems due to obesity.

Reasons for adherence to the lifestyle modification

Participants said they follow their diet and exercise schedule with support from their peers. In addition, they discussed that their peers made them realise how to do the planned activities.

My daughter, who is my peer, keeps reminding me that 'those people are helping you with your weight and aren't charging any fee. They're putting so much effort, so you should put in that much [effort] with them. (Participant 008)

Participants reported that the study’s weekly phone calls to assess compliance also helped them follow the planned activities as it worked as a reminder.

You guided me, and it made me feel good. You would call and ask about me, so it would remind me [to follow the guidance] as well. (Participant 008)

Other reasons for adherence included accountability measures and experiencing health issues that kept the participants in check. Participants showed more compliance with the programme due to the study team’s regular follow-ups and weight monitoring.

Reasons for continuing participation

Continuous diet and exercise instructions and monthly weight status updates encouraged participants to remain in the study. They felt changes in their weight and realised that they could do it if they had some support.

I feel there’s quite a lot of change in my weight; that’s why I'm still working with you. If I didn't feel such changes, I might have cancelled this by now, but I've brought some changes within myself, which is why I feel like I can do this. If I can get more support, I can do this. (Participant 014)

Barriers to adopting a healthy lifestyle

The barriers to adopting a healthy lifestyle were the existing health conditions of the participants that prevented them from performing regular physical activity. However, they kept trying to follow their scheduled activities.

I started exercising, but I have some diseases because of which I am unable to continue. I tried, but I didn't make it a routine that I'd do daily, but I still kept trying to walk more. In everyday tasks, I tried to do work that required me to sit less and walk more. (Participant 008)

Household responsibilities and a separate diet routine were barriers to lifestyle modification adherence. However, participants tried to follow their schedule and accepted that following a healthy lifestyle is doable if a person gets motivation. One participant shared that she did not face difficulty following a healthy lifestyle. Besides, it helped her to follow a proper routine.

There are difficulties like making a salad every day and going to the market daily to bring fresh [food]. (Participant 014)

Experience with online training

The participants expressed satisfaction with the online training and considered it a positive learning experience. In addition, they found it helpful and a source of motivation and showed interest in continuing this training in the future. They were also grateful that following the standard operating procedures (SOPs) during the pandemic, they received continuous training by staying home. Participants stated that they received beneficial guidance for the first time like this. The participants also expressed their satisfaction with the training sessions by recommending them to others.

[The training] was very nice, I got to learn something from it… it’s been very helpful. I wish to continue this training further in life as well. (Participant 003)

Findings from peers

Four themes emerged from the IDIs: reasons for participation, factors that helped engage participants, difficulties in engaging participants and online training experience. Figure 3 summarises the main themes with their sub-themes.

Figure 3

Themes and subthemes (peers).

Reasons for participation

The participant’s family members offered to be their peers, so they showed interest and considered it an excellent opportunity to work on their weight alongside their participants.

Firstly, my father wanted to participate and lose weight, and it’s also good for him since he has diabetes, so keeping his weight in check is the right thing to do. Secondly, I'm also overweight, so it would be good if we could work together to lose weight. (Peer 011)

One peer highlighted the importance of immediate family participating as a peer as they can provide the best peer support due to their close bonding with the participants.

Only a daughter can understand her mother so well. Whether it’s how much she’s eating, how everything’s going- only she can stop her [from following an unhealthy lifestyle]. If someone else says something, she won't listen to them, so only we can guide and help our parents. (Peer 002).

Peers also signified their preference to participate due to the programme structure, guidance and follow-up style, allowing them to receive detailed information and feedback in their homes without charges.

Factors that helped engage participants

Peers said they reminded their participants to follow a healthy diet and exercise regularly. In addition, they ensured that their participants adhered to all the planned activities discussed and suggested during the training by providing support and motivation. Peers also convinced participants by emphasising the impact of reducing weight on their physical appearance. One peer mentioned that she helped the participant follow dietary adherence by cooking healthy food for him.

Whenever she would wake up in the morning, I would remind her to go for a walk so that she would go for one with her friend. Other than that, when we would go to a wedding, etc. I would tell her to avoid cold drinks and biryani. (Peer 003).

Difficulties in engaging participants

Peers reported convincing participants to follow a healthy diet was sometimes challenging, especially when their favourite food was cooked. However, they always tried to encourage them to choose healthier food.

Before [the intervention], we ate white flour, but now, we use whole-wheat flour and mix some [of the white dough] in it. We're trying to stop using white flour because it doesn't provide much [nutrition] and causes more weight gain. So, we are following your guidance. We've also lessened our rice intake- our biggest weak point, but we were able to lessen it. (Peer 002)

Other peers did not face difficulties while helping their participants. For example, one peer reported that his participant was already compliant with the diet and exercise, and this programme helped her comply more to achieve weight loss. Others said through this programme; participants realised the importance of following a healthy lifestyle.

Experience with online training

All peers were satisfied with the way of delivering the intervention. They were thankful for being a part of this programme, which allowed them to learn healthy ways to lose weight. Furthermore, they appreciated the efforts of implanting this programme, due to which their participants reduced weight by following a healthier lifestyle.

The experience has been good. She [the participant] benefited from the training and all the tips you gave, and thank God her weight has decreased a lot. (Peer 003)


This 1 year pilot study assessed whether a peer-supported lifestyle modification intervention delivered through WhatsApp for weight reduction is feasible to conduct a definitive trial. This pilot study evaluated the screening of study participants through phone calls, recruitment, retention and monthly interview response rates. We encountered various challenges during screening on phone calls, including lower response rates and higher refusal and migration rates. However, the peer-supported lifestyle modification intervention delivered using WhatsApp was found promising, as weight loss and reduced calorie intake have been seen throughout the study. In addition, our qualitative findings indicate that the facility of online training, peer-support assignments, monthly follow-ups and updates on weight status are the facilitators of following a healthy lifestyle. Household responsibilities, separate routines and health conditions are barriers to a healthy lifestyle. Furthermore, we found online training a good initiative as participants and peers considered it a positive learning approach in terms of convenience and accessibility.

Literature from the West supported the role of peers in lifestyle modification and weight reduction programmes as it improves adherence. For example, Marquez et al (n=278) and Winston et al (n=245) found significant weight loss at 12 months involving social support from family, friends and coworkers for dietary and physical activity goals.58 59 However, the evidence is based on the Western population using randomised-controlled trials with a larger sample size. Similarly, we found a substantial decline in mean calorie intake throughout the study, whereas a noticeable weight loss, especially at 9 months. These results are also consistent with our qualitative findings, in which participants highlighted that they received continuous reminders, support and motivation from their peers as well as study’s proper follow-ups, constant guidance through online sessions, and updates on their weight status helped and encouraged them to better dietary adherence.

Moreover, our study participants accepted during the IDIs that they tried to follow a routine for their exercise plans; however, they could not perform physical activity regularly due to the existing health issues. It was also reflected in our quantitative results, which showed increased calorie expenditure only at 3 months. In addition, the findings of the SSQ also demonstrated higher mean scores for most questions related to diet encouragement, whereas the lower mean scores for physical activity-related questions. However, our study was planned to inform about the delivery of a definitive trial and hence was not statistically powered to demonstrate evidence of the intervention’s effectiveness.

Other reasons for the participant’s avid interest in the study were the programme structure and the nature of delivering the intervention. Participants highlighted the involvement of family members as peer support and providing intervention through WhatsApp are the uniqueness of this intervention programme. Other literature also indicates that digitally delivered interventions and peer-support assignments are a better opportunity for the participants and their families as they are easily accessible and convenient.60–62 In contrast, the issues faced by the participants during the intervention were adjusting their dietary and physical activity routines due to experiencing food cravings, inconveniences in food preparation and existing health conditions; these issues have also been discussed in other literature.63 64

There are several challenges and successes associated with this pilot study. We approached participants through phone calls to assess eligibility due to the declaration of the COVID-19 pandemic. However, a higher proportion of non-respondents and refusals were reported in our study, making it an ineffective screening approach. Challenges in recruiting participants in research studies during the COVID-19 pandemic using different methods, including post/email and phone calls, were a well-known issue.65 66 However, delivering intervention using WhatsApp and the peer-support assignment was found promising in our study as the diet-related intervention was followed more closely than physical activity among participants due to the existing health issues. In addition, we found participant retention in the study and their monthly interview response rates satisfactory.

Our study has several strengths as we used a participant-nominated peer-support approach with lifestyle modification to improve compliance and provide better support and motivation. Due to the COVID-19 pandemic, we used a more time and cost-effective method for delivering lifestyle modification education to the participants and peers using WhatsApp voice calls, making it convenient and easily accessible. Our study population is a good representative of the target population as they belong to a slum setting; however, we enrolled a higher proportion of females as we approached most of the households in the morning, during which most of the women are available at home, this may limit the generalisability. Our study has some limitations as we used a single group pretest and post-test design approach for pragmatic reasons, and the absence of a comparison group is an important limitation of the study. We interviewed participants in person or over the phone following the SOPs of COVID-19, which may have affected our results. However, we ensured that all participants were interviewed at least three to four times in person over 12 months.


The preliminary evidence of the study demonstrated that a peer-supported lifestyle modification intervention delivered using WhatsApp was feasible. The findings also showed a considerable reduction in mean calorie intake and weight loss throughout the study; however, improvement in calorie expenditure was less. The findings of the study indicated the potential for expanding this work by implying several modifications, such as changing the screening methods to a door-to-door approach. Furthermore, close monitoring and frequent refreshing sessions based on motivational interviewing would be beneficial for better adherence to physical activity. We used participant-nominated peers from their families to support lifestyle modification adherence. Considering other members as a peer from the community might also be equally supportive. One of the cadres would be the community health workers, who play an integral role in supporting the healthcare system within communities in Pakistan. Since they reside and conduct door-to-door visits within communities and are considered well-trusted and respectable members, they may help improve recruitment and retention rates and hence programme effectiveness. The quantitative and qualitative findings of the current pilot study supported the scale-up of this work with the recommendations to promote a healthy lifestyle and improve people’s quality of life.

Data availability statement

Data are available upon reasonable request.

Ethics statements

Patient consent for publication

Ethics approval

This study involves human participants. The study was approved by the Ethical Review Committee of the Aga Khan University (Ref: 2020-3550-9021). Participants gave informed consent to participate in the study before taking part.


We would like to thank our study participants and peers who took part in this study. We thank our data collectors who helped in data acquisition.


Supplementary materials


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  • Contributors RI and SN conceptualised and designed the study. SN was involved in the execution and acquisition of data and supervised all field activities. SN, AJ and UK were involved in the quantitative data analysis and interpretation. SN and KAH were involved in the qualitative data analysis, interpretation and manuscript writing. RI, IA and ARS reviewed and provided scientific revisions to the manuscript. All authors agreed prior to submission to take responsibility and be accountable for the contents of the manuscript. All authors read and approved the final manuscript. SN is responsible for the overall content as guarantor.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests None declared.

  • Patient and public involvement Patients and/or the public were not involved in the design, or conduct, or reporting or dissemination plans of this research.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Supplemental material This content has been supplied by the author(s). It has not been vetted by BMJ Publishing Group Limited (BMJ) and may not have been peer-reviewed. Any opinions or recommendations discussed are solely those of the author(s) and are not endorsed by BMJ. BMJ disclaims all liability and responsibility arising from any reliance placed on the content. Where the content includes any translated material, BMJ does not warrant the accuracy and reliability of the translations (including but not limited to local regulations, clinical guidelines, terminology, drug names and drug dosages), and is not responsible for any error and/or omissions arising from translation and adaptation or otherwise.