Primary research studies involving places of worship and weight-related outcomes, written in English and published 2013–16, were sought. Electronic searches of Medline, Science Citation Index, and PubMeD databases, scanning of the reference lists of identified articles, and hand searching of journals were conducted. No restrictions relating to participant age, ethnic group, or religion were imposed. The 16 studies in 15 articles identified reported on or proposed formative research, quasi-experimental, and cluster randomized trials that explored or tested the feasibility and efficacy of faith settings for achieving weight-related change. The focus was obesity per se for some studies, but in others, weight loss was the route to addressing risk of diabetes or cardio-vascular disease. Half of the studies were aimed at African-American men and women [
23•,
24‐
29], with the remainder among Latinos [
30,
31], South Asians [
32•,
33], American Indians [
34], Black Caribbeans [
33], Black Africans [
33,
35], Samoans [
36], and general church attendees without a particular ethnic focus [
37]. Studies were located in the USA [
23•,
24‐
31,
32•,
34,
36], UK [
33,
37], and Australia [
35]. The two studies reporting the very earliest qualitative exploration of the potential for intervention development are not critiqued further [
35,
36]. Of the substantive interventions with weight-related outcomes (
n = 11 studies), four were faith placed (located in faith organizations without any spiritual message) [
24,
29,
31,
33] and the remainder had tenets of religion integrated into the programmes (faith-based). Interventions were principally delivered to groups, and in most of the articles, the intervention sessions and cultural tailoring were richly described. The majority of studies targeted overweight participants and also included those already obese. Generally, studies were often also open to non-overweight participants, and some additionally involved the wider congregation in healthy lifestyle activities, regardless of weight status. Therefore, the studies included can be deemed as contributing to primary and secondary prevention, as these categories are often blurred in addressing obesity, as in other multi-factorial conditions [
38]. In all but one study [
37] (diet only) both dietary and PA behaviours were targeted to effect weight change. Intervention sessions led by members of the community trained to deliver the programme were a common feature of most of the studies. Where this was not the case, the intervention was delivered by dietitians and fitness experts [
27] or a church minister who was also a trained nurse [
25]. Two studies included children [
33,
34] and two targeted females only [
25,
34], and male participation was low (12–29% of the sample) in those studies involving men and women. The studies and their findings are further described then critiqued subsequently.
Studies Including African Americans
A completed cluster randomized controlled trial [
23•] and the protocol for a cluster RCT [
28] were identified. Fit Body and Soul (FBAS) included 604 African-Americans in 20 churches [
23•]. The study was a community adaptation of the US diabetes prevention program (DPP), a multi-centre clinic-based programme successful in achieving weight loss through intensive dietary and PA modification to reduce risk of type 2 diabetes [
39]. Participating churches were randomized to receive FBAS or a generic health education (HE) intervention. Intervention dose was 12 1-h weekly sessions with six monthly 1-h ‘booster’ sessions. HE sessions were consistent in intervention dose and attention but involved only a prayer and discussion of a health topic. All participants completed the study, and at 3-month and 12-month follow-up, FBAS participants had significantly greater weight loss compared to the HE arm. After the success of the pilot phase [
40], the wholeness, oneness, righteousness, deliverance trial (the WORD), was established, with a target sample of 450 men and women in 30 churches, and is currently in the recruitment phase [
28]. The intervention will have two arms; churches will be randomized into a 16-session weight loss intervention or the same intervention followed by a 12-week weight maintenance protocol. Follow-up at 6, 12, and 18 months is planned. Comprehensive description of the session content includes detailed explanation of the spiritual message associated with each session.
One small-scale RCT and five studies with quasi-experimental designs were also conducted among African-Americans [
24‐
26,
29]. Follow-up periods ranged from 2 to 6 months. The Living Well by Faith (LWBF) pilot programme [
27] involved 106 participants in five churches randomly assigned to receive LWBF or a limited intervention control of one educational workshop. The LWBF consisted of an intensive 8-week course of bi-weekly 90-min sessions, together with individualized ‘wellness’ plans. Follow-up was 2 months. The study was completed by 97% of the LWBF group and 75% of controls. Significant decreases in weight, BMI, and body fat were evident in the intervention group compared to the controls. Seventy participants in two churches took part in the waitlist-controlled Heart Smart Church (HSC) study [
24], with no loss to follow-up reported. The bespoke intervention was delivered in 3–12 group sessions, with additional individual face-to-face meetings [
24].
In the remaining four studies among African-Americans, there was no control group, a pre-/post-test design was employed, and follow-up ranged from 3 to 6 months. Whisenant and colleagues [
25] describe two studies. In the first of these, 35 female participants took part in a 3-week intervention designed by the researchers; 11 individuals were lost to follow-up [
25]. The second study was delivered by a trained nurse congregant to 21 participants (15 female) from two churches over 12 weeks [
25]. The Turn the Beat Around (TBA) study, based on the existing With Every Heartbeat is Life intervention components, was delivered in six weekly sessions to 201 men and women in nine churches, 94% of whom completed the study [
26]. Feasibility of achieving weight loss using a further modification of an intervention developed from the DPP was tested in the Lifelong Prevention Program (LPP) among 13 participants, 11 of whom completed the study [
29]. Sixteen group sessions were supplemented with six personalized telephone support sessions [
29]. Positive weight/waist circumference outcomes were reported for all four of these quasi-experimental studies, but did not reach statistical significance in the TBA study [
26].
Other Ethnic Groups
Studies involving ethnic groups other than, or in addition to, African-Americans included one small cluster RCT [
31], three pilot-scale studies with a quasi-experimental design [
30,
32•,
34], and studies describing completed or proposed formative work [
33,
37]. The
Un Estilo De Vida Saludable (EVS; ‘healthy lifestyle’) study among 58 Mexican-Americans (78% female) was also an adapted version of the DPP, involving the randomization of two churches to receive either the EVS intervention or an attention-control intervention [
31]. EVS was a 5-month-long programme with an intensive phase of eight 2-h weekly sessions, followed by a maintenance phase of three monthly 1-h sessions. The attention control arm received the same intervention dose and attention, in sessions providing general information on health conditions (but not diabetes) delivered by a bi-lingual nurse. In the study, overall attrition was high, with only 57% (
n = 33) of the total sample completing the study and particularly marked in the control group (40% attrition in this group). Greater weight loss, lower waist circumference, and BMI were reported for the EVS vs. the control group.
The two studies with control groups but non-randomized design included the first pilot community-based diabetes prevention programme among Sikhs in New York [
32•], and a study initiated with formative qualitative research, building to a pilot cardio-vascular disease prevention trial among Lumbee Indian women in NC, USA [
34]. Sikh participants recruited in Gurdwaras (Sikh temples) were allocated to an intervention arm or control according to residence in two locations. A total of 76 participants were allocated to intervention and 50 to control. Follow-up was at 3 months and 6 months. Sessions included interactive 2-h sessions held at 3-week intervals over the 6-month study. Intervention participants also received follow-up phone calls between sessions for individualized action plans. Control participants were advised to maintain standard care and prevention activities, but received the full intervention at the end of the 6-month study period. Seventeen (22%) of the intervention participants were lost to follow-up (compared to only one in the control arm), but demographic factors were similar to those who remained in the study. In the treatment arm, weight was significantly lower than at baseline, with almost 5 lbs lost on average, although there was no significant difference in weight loss between the treatment and control groups. Formative research among the Lumbee women [
34], including review of the literature, meetings with church leaders, and an assessment of potential church venues, followed by a series of stakeholder focus groups, led to the development of intervention content and delivery. Four churches were subsequently recruited and two each assigned to the intervention arm or a delayed intervention control, according to geographic location. The bespoke intervention of weekly classes over a 4-month period was delivered in all four churches; however, of the 165 participants enrolled, only 27% attended the intervention. Barriers to implementation included difficulties scheduling sessions due to competing church activities and resistance to dietary change. The impact on BMI is yet to be reported.
Also in the USA, Gutierrez et al. [
30] targeted low-income, urban African-Americans, and Spanish-speaking Latino parishioners in the Fine, Fit, and Fabulous study. In this pre-/post-test intervention, 253 participants were recruited into the study of which 183 (72%) completed the programme and 63% provided sufficient data to be included in weight loss analyses. The intervention was developed by church members and consisted of a 12-week programme. Originally designed for African-Americans, the curriculum was additionally culturally and linguistically adapted for Latinos in Spanish-speaking churches; however, the article lacked detail on intervention development and content. On average, participants lost a significant 2% (4.38 lbs) of their body weight compared to baseline, with weight loss being greater for the African-Americans than that for the Latinos. Analysis stratified by BMI category indicated that percentage weight loss was greatest among those who were initially overweight (BMI 25–29 kg m
−2) compared to those in normal or obese categories.
Feasibility of childhood obesity intervention components and delivery among children aged 8–13 years was explored in temples, mosques, and churches compared to that in schools in London, UK [
33]. Potential intervention components were informed by focus groups with children and parents [
41] and extant literature and tested among 155 boys and girls in schools and 33 children in places of worship in one-off sessions. Mixed qualitative and quantitative evaluation of recruitment and acceptability and feasibility of the interventions indicated straightforward recruitment of schools, multi-strategy approaches to recruitment of places of worship, low response rates of organizations, but high participation rates of individuals. Evaluation coverage, however, was more consistent in places of worship than in schools. Also in England, Lycett et al. [
37] propose a small Christian church-based feasibility study among ten participants with the aim of using the findings to design a cluster RCT. No particular social or ethnic group is targeted and the intervention will be open to those who do not ordinarily attend church. The ten planned 90-min weekly sessions will focus on ‘intuitive eating’ without explicit mention of weight loss. There is no indication given that there was input by potential stakeholders in the intervention design and was the only study reviewed which did not include a PA component.