A systematic review of patient barriers and facilitators for implementing lifestyle interventions targeting weight loss in primary care

Numerous barriers are experienced by people with overweight and obesity that play a role in the implementation of lifestyle interventions. This systematic review aims to investigate the barriers and facilitators for children and adults with overweight or obesity when implementing lifestyle interventions targeting weight loss in primary care. A systematic review was conducted by searching four databases to identify eligible studies (1969–2022). The Critical Appraisal Skills Program was used to assess the study quality. A total of 28 studies were included, of which 21 focused on adults and seven on children and their parents. Thematic synthesis of the 28 studies included identified nine key themes, of which support, role of the general practitioner, structure of the lifestyle intervention program, logistics, and psychological factors were the most common. This review shows that a strong support system and a personalized lifestyle intervention are essential components for successful implementation. Additional research is needed to identify whether future lifestyle interventions can take these barriers and facilitators into account and still be feasible for losing weight.

other treatments (e.g., bariatric surgery), 13 poor attendance and compliance rates are often reported. 14,15 Primary care is the ideal setting for initiating lifestyle interventions, with the general practitioner (GP, family doctor) playing an important role. 16 Internationally, primary care guidelines recommend targeted assessment of people with overweight and that BMI should be used as a routine measure for diagnosis. 10 As GPs are seen by patients as a reliable source for providing advice and information and have access to referral service resources for appropriate lifestyle support, they are well positioned to identify individuals with overweight and address lifestyle factors within a consultation. However, implementation of lifestyle interventions within primary care remains a challenge, 17 due to a broad range of factors such as a lack of proven effectiveness of the interventions, insufficient time in consultations, the belief that individuals with overweight or obesity lack motivation, and lack of clarity as to whether lifestyle support is part of a GP's core tasks. [18][19][20] Far less is known about the perspectives of individuals with overweight or obesity and the barriers and facilitators they perceive for the implementation of lifestyle interventions. Although several studies have focused on the perspectives of children and adults, 21 there is no overview of the barriers and facilitators. The objective of this systematic review is therefore to investigate the barriers and facilitators for children and adults with overweight or obesity affecting the implementation of lifestyle interventions targeting weight loss in primary care.
The results of this review will enable healthcare providers (HCPs), policy makers, and individuals with overweight and obesity involved to improve the implementation of future lifestyle interventions.

| METHODS
This systematic review was conducted and reported in line with the PRISMA statement. 22 The protocol for the review (ID CRD42021283928) was registered before initiating data extraction on November 4, 2022 and can be found at https://www.crd.york. ac.uk/PROSPERO/display_record.php?ID=CRD42021283928.

| Search strategy
With the support of the Erasmus MC Medical Library, a search strategy was developed to find studies directed at barriers and facilitators for implementing lifestyle interventions for people with overweight or obesity in primary care. Four databases (Embase, MEDLINE, CINAHL EBSCO, and Web of Science SCIE & SSCI) were searched on February 16, 2021 using keywords such as general practice, lifestyle, body weight management, overweight, obesity, barrier, facilitator, patient attitude (see Appendix S1 for the full search strategy).
Studies written in English and Dutch were included and congress abstracts from before 2018 were removed from the Embase database.

| Study design
Studies with qualitative outcomes from interviews (including group interviews), field notes, and questionnaires were included. Quantitative outcomes were not included.

| Intervention
Studies had to be performed in primary care and directed at lifestyle interventions with the aim of losing weight. Dietary intake, physical activity, healthy eating behavior, psychological guidance, or a combination were deemed to be lifestyle interventions and were therefore included. Surgical or pharmacological interventions were excluded.

| Outcome
Studies needed to assess the barriers and facilitators for individuals with overweight or obesity towards lifestyle interventions. Barriers are defined as reasons that make it more difficult for the participant to start or attend a lifestyle intervention, whereas facilitators are defined as reasons that make it less difficult for the participant to start or attend a lifestyle intervention. Studies without a proposed intervention were not included, as the barriers and facilitators reported are not applicable in this review. Studies that assessed barriers and facilitators for weight management that was not delivered within a program were also not included, as this is not a specific lifestyle intervention.

| Selection of studies
All screening steps were performed by three researchers independently of each other. A double-screening approach was utilized where MJ assessed all studies whereas half of the selected studies were allocated to MM and NJ. First, titles and abstracts of each study were screened. Second, the full text of each study was screened. MJ, MM, and NJ read each study independently and included or excluded the study, stating a reason for their decision. Disagreements were resolved by discussion.

| Quality assessment
The Qualitative Studies Checklist from the Critical Appraisal Skills Program (CASP) 23 was used to assess the quality of each included study (see Appendix S2 for the checklist). The checklist consisted of 10 different domains, each accompanied by questions to help assess the quality. The questions marked as highly important are listed in Appendix S2. Two researchers (MJ, NJ) independently assigned a score of 0 or 1 per domain to each study; to get a score of 1, the most important questions had to be answered. Disagreements were resolved through discussion and by consulting the third researcher (MM). An overall score ranging from 0 to 10 was calculated from the 10 domains, with higher scores indicating higher study quality.

| Data extraction and synthesis
Study characteristics were extracted following a standardized format including setting, study aim, population, lifestyle intervention, inclusion and exclusion criteria, data collection method, and relevant outcomes. The study characteristics were extracted into a table by MJ and verified by NJ.
Studies of the barriers and facilitators for adults were analyzed separately from studies including children and/or their parents.
Thematic synthesis was used to find the key themes across the various studies. 24 First, all the verbatim results of the studies were entered into ATLAS.ti version 9, and initial codes were assigned. Connections were then made between the different codes to group them into overarching themes. In the final step, major analytical themes were constructed to generate new insights into the implementation of the lifestyle interventions and obtain a better understanding of the most common barriers and facilitators. A code needed to be assigned at least five times to be classed as "important." This threshold was lowered for themes that did not reach the threshold, as some themes did not include as many codes compared to others.
In the registered protocol, it had been stated that the data would be extracted and grouped using the Consolidated Framework for Implementation Research (CFIR), but it was decided to use thematic analysis as this was more suitable for this systematic review.

| RESULTS
The search strategy identified 12,601 records. After removing duplicates, 6679 studies were screened by title and abstract; 347 articles were included for full-text screening, of which 28 studies were eligible for data extraction and qualitative synthesis. Figure 1 shows the screening process and reasons for exclusion.

| Study characteristics
The 28 included studies were divided into two groups: 21 studies classified as "adult" and 7 studies as "child/parent." The study characteristics can be found in Table 1 (see Appendix Table S3 for additional information).
The total number of adults and children (excluding parents) who were interviewed was 895. More women participated in the studies, although one study targeted men as the lifestyle intervention was specifically made for men with obesity 25 The interventions included e-health interventions, 26,27 existing commercial programs, 28

| Quality assessment
Total scores ranged from 5 to 10 with an average of 7.9 (see Table 2), indicating generally high quality. Most studies did not fulfil the criteria specifying the relationship between the researchers and the participants, explaining the data analysis sufficiently or justification of how the data were collected. In addition, two studies 26,31 did not meet the criteria for the research design domain as they had a considerable amount of time between the end of the lifestyle intervention and the interviews with the participants.

| Qualitative findings
After thematic synthesis, 310 codes were identified and assigned to 1007 quotations. These codes were grouped into nine different themes, divided between barriers and facilitators. The nine key themes identified were support, psychological factors, health of individual, role of GP, role of program staff, program structure, logistics, e-health, and child/parent-specific.

| E-health
Three studies described barriers or facilitators that are specific for online lifestyle intervention program. 26,27,29 Two studies reported on barriers for online lifestyle intervention programs; disliking certain aspects of the website was the main barrier identified. 27   Lack of support from close ones "Similarly, Jackie, who lost weight initially but regained weight at the end of the project, confessed to the need to have some sort of social support: 'I really admire people who can actually go on their own and do their thing, for themselves and be totally focused but I'm just not like that'." (Jackie, aged 52) 2

2,3,7-13
Lack of support from general practitioner "My family physician would give me the standard, 'Eat less fat, eat less sugar (chuckle), exercise more',-and that's not going to cut it." (Patient 2) 11 2, 3,9,14,15 Critical position of family to change "I'm trying to feed the family with things that they normally like and they're very entrenched in set behaviours and my husband does the shopping and it's quite difficult to get him to buy different things." (Participant 5, F, 54). 15

3,14,16,17
Good support from close ones "To sustain a lifestyle change, most of the patients said that the most important person was their partner/spouse or another person close to them who continued to regard the lifestyle change as important." 14 3,4,11,12,14,16,18-20 Good support from fellow participants "I enjoyed it. I learned a lot and I participated a lot. I got to know some people who ended up going all the way through the whole program with me and you know we became friends. (32 year-old female, in-clinic group counseling)" 12

17,20,21
Positive position of family to change "Some women had followed the programme alongside their husbands. In other households the children snacked less, or the whole family had started to eat more fruit and vegetables, or to take more exercise. Weight gain is not lifestyle related "I can tell you where I got pretty heavy at one point, really heavy, and that's due to the fact I went through prostate cancer. Also, I've taken radiation, and then hormone therapy to knock down your testosterone, which makes you gain weight… They just told me it was a common thing to take place when you're taking hormones. So, don't panic!" (Patient 10). 11 (Continues) de JONG ET AL.

T A B L E 3 (Continued)
Theme

Codes Example quotes
Role of general practitioner 1,6,8,11-13,23 General practitioner not involved towards problem "'This is who you could talk to get some help and some information' … anything practical was lacking … If I go to the doctor because I've broke my arm they're not going to tell me 'You broke your arm, go get it bandaged up', they're going to do something about it or at least tell me what to do about it … I found that a bit annoying at the time. Personalized support/ referral from general practitioner "Overall, patients equated the letter from their GP with a more typical NHS referral letter from primary to secondary care, and recognised it as being the key means to access specialist resources and services. As a result, the letter played an important symbolic role for participants." 1 Role of program staff 8,13,20 Difficult to reach program staff "I look forward to participating in the program, but it is very hard to get in touch with someone." 8 2,8,11,14,19,20,23 Lack of active follow-up "Several patients found it difficult to reach program staff and found the lack of follow-up procedures to be disconcerting: My doctor referred me to the program and said that someone would contact me. They never did, so I lost interest." 8

3,6,8,11,12,25
Program staff is friendly and easily accessible "They seemed to really let you know what they had available, that they wanted to be able to help you out, which is nice." (Patient 14). 11 2,3,8,11,12,18,22-24 Active follow-up "I do better personally if somebody's checking up on me, when you wrote and said you were gonna be contacting us, it was like, I'm thinking oh no, quick, I better do something, and so I think if you were checked up on after a few months, or something, that might help.it seems like that's what I need, is somebody every now and again to say hey are you still doing it, you know, how are you getting on." 2 Program structure (barriers) 7-13,15,16,19 Disliking certain aspects of group sessions "I just would have liked a bit more one-on-one. Yeah, not just in a group session, you know. Like, yeah, one-on-one so that you are able to sort of be able to talk about your own child, you know. Not just be in the group and then, 'what do you think'? and then. I wanted to say sort of sometimes some things, but you know, I just prefer, to just be on my own. So that's what I would have liked a bit more, was the one-on-one." 13

1,15,20
Feeling that individual is not the target population "I'm an overweight, middle-aged woman and it seemed to me that this was geared up to young, fit people who wanted to exchange views about being even younger and fitter." (Participant 9, F,49). 15 2,6,7, [10][11][12][13]15,16,19,20 Lack of personalized approach "For intervention non-initiators, concern that content would not be individualized or match their specific life situation was identified as favoring non-initiation of interventions." 16 15,17,23,24,27 Program is too much effort "They emphasized that it can be hard to stick with the programs (e.g., to keep tracking points/calories and change their daily routine and eating habits). They also noted that weight loss is a long and difficult process." 24

15,16,24
Program tools are difficult to use "For some patients, moving from the fortnightly visits to the 3-monthly follow ups created a challenge. They keenly felt the reduced support and found it harder to sustain their motivation and recover from lapses." 22 Program structure (facilitators) 2, 6,7,9,10,12,16,21,25 Liking aspects of group sessions "That's how I felt I benefitted, by listening to everybody and how they were dealing with each situation which was known to me, I thought 'oh yes, I know what they're talking about' and I thought 'oh that's how they deal with it'" (P1). 25 6, [8][9][10]12,15,16,[19][20][21]23,24,26 Liking certain aspects of program "The main reason men gave for adhering to the programme was that they enjoyed it: 'You actually looked forward to coming'." 21 [1][2][3]14,15,17,22,27 Monitoring of health and weight status "The regular check-ups and the fact that you're being monitored and the fact it's part of a clin-ical trial, you can't just give in because you're letting other people down as well as yourself. That keeps you honest and it makes it a lot easier. I would say my chances of being where I am just now without that help would be as much as half"(P3, T4). 17 1-3,6-12, 14-18, 20-23,25,26,28 Personalized approach "Participants were pleased the programme did not simply focus on weight loss and appreciated being able to choose the weight management approach that best suited them: 'You personalised it so it was something that would work for you'.

15
Using internet regularly "Participants described regularly using the internet to look up topics of interest and this may have facilitated their willingness to try online weight loss programmes." 15 Child/Parent specific 8,28 Parents unable to keep child from unhealthy behavior "One frustration was getting her son (J.Q.) away from the computer. She rated this as a very important step toward increasing his physical activity level and getting to school on time; however, her efforts had not been effective." 28

28
Parents not supporting child in weight management "Alternately, some parents actively undermined the child's plan by continuing to buy whole milk, sweetened drinks, and high-calorie snack food." 28 28 Parents involved towards weight problem "Both parents attended the third intervention visit, and the wife requested information about healthier food choices. The provider gave an example that drinking 12 ounces of a sugar drink, such as a can of soda a day, could result in a 10-pound weight gain in adults over a year. 3.3.9 | Child/parent-specific Child-or parent-specific barriers and facilitators were reported by four studies in total. 33,35,36,38 Barriers included parents being unable to keep their child from unhealthy behavior and parents not supporting their child in weight management. 35,36 Facilitators included parents' involvement in the weight problem of their child and the idea that weight loss increases the self-esteem of the child. 33

| Interpretation of findings in relation to existing literature
A strong support system from those close to the patient, fellow participants, the GP, and program staff was found to be an important factor for an individual trying to lose weight through a lifestyle intervention.
The GP was often reported to be the most important person. Participants appreciated it when their GP made a personal referral, initiated the conversation, or showed empathy, as well as a GP who was involved throughout the intervention, and actively followed up on their progress. Many individuals were not aware of their weight classification and the corresponding health risks; education by the GP was therefore essential for initiating and successfully finishing the lifestyle intervention. Involvement of the GP increased the feeling of being taken seriously and provided motivation to lose weight and finish the intervention. In contrast to the positive view of participants towards their GP, a systematic review showed that GPs do not feel responsible for weight management and perceive numerous barriers, including a lack of consultation time. 20 Other studies found that GPs are often reluctant to approach weight management discussions for fear of causing embarrassment or compromising the doctor-patient relationship. 53 59 Our review also found that monitoring weight and health (e.g., a health check and weight assessment at each visit and self-monitoring) was an important feature for participants to stay motivated and compliant. Self-monitoring is strongly associated with weight reduction 60 and should therefore be integrated into future programs by providing easy-to-use tools (e.g., a mobile application showing progress). In line with our findings, another study found that features, such as the time of the lifestyle intervention, active follow-up, and self-monitoring, as well as individual and group counseling, were seen as important to individuals. 61 Future intervention studies should therefore consider personalized lifestyle interventions in which participants are involved in the decision-making, as this can positively influence implementation and compliance for those programs.
Individuals reported experiencing a variety of mental health issues (e.g., depression and anxiety) and other psychological factors (e.g., lack of confidence and stress), which may impact an individual's perception towards their weight problem. A review found that greater selfacceptance and a higher self-esteem were key steps for developing motivation to undertake weight control treatments, 62 which is in line with the facilitators found in the current study. Although there are numerous reports stating that mental health should be a key element of lifestyle interventions, 63,64 many participants in this review still report they cannot do it on their own and need more psychological guidance. Program staff should therefore be trained to give psychological guidance, such as motivational interviewing, 65 and inform the GP of the issues. As lifestyle interventions are multicomponent programs and multidisciplinary, it might not be feasible to guarantee that the HCPs involved can help participants with mental health conditions. Future lifestyle interventions should therefore include a psychologist or a specialized lifestyle coach to assist individuals who struggle with psychological barriers to weight loss.

| Strengths and limitations
This is the first qualitative systematic review that focuses on the barriers and facilitators for individuals with overweight and obesity towards lifestyle interventions in primary care. As this review consists of a large sample of studies, it is likely that all the studies combined provide a result that is generalizable to the wider population. The lifestyle interventions took place in different countries targeting different study populations.
There are some limitations that should be taken into consideration. Only a few studies in this review focused on online lifestyle interventions or child-specific lifestyle interventions. Caution is therefore needed when interpreting the results of those themes. Also note that no additional studies were assessed for eligibility by checking the references of the studies included.

| Clinical implications
This review shows the importance of having a strong support system and a personalized lifestyle intervention program. The parties involved, such as policy makers, HCPs, participants, and those close to them, need to be aware of the reported barriers and facilitators to improve implementation and further optimize lifestyle interventions.
Proposed strategies for future lifestyle interventions are providing structural support (e.g., through peer support), educating HCPs about how to improve the confidence and motivation of participants, educating GPs about the important role they play and how they can contribute, and not having a participation fee. As web-based interventions are becoming more popular, it is important that onlinebased lifestyle interventions contain relevant and attractive information with self-monitoring applications adapted to the target population. When a new lifestyle intervention is being developed, the parties involved should include program staff of existing lifestyle interventions, GPs, and individuals with overweight or obesity in an "experience-based co-design". 66 This ensures that all parties have the opportunity to provide their opinion and, ultimately, improve future lifestyle interventions.