Opinions from the experts: Experiences of adolescents with severe obesity participating in meal replacement therapy

Summary

Background

Meal replacement therapy (MRT) is a structured treatment that is effective for short‐term weight reduction in adolescents with severe obesity. However, like other interventions, MRT response is variable.

Objective

The goal of the current study was to characterize the experience of adolescents with severe obesity participating in MRT.

Methods

Seventeen adolescents with severe obesity participated in semi‐structured, individual interviews about their experience participating in MRT. The authors used a biopsychosocial model as the theoretical framework and data was analysed using Interpretive Phenomenological Analysis. A biopsychosocial model views an individual's health as a blend of biological characteristics, behavioural factors, and social conditions.

Results

Results showed that adolescents with severe obesity described three biopsychosocial factors that were central to their experience with MRT: (1) scheduling and planning, (2) social support and pressure, and (3) intrapersonal factors. Specifically, adolescents with severe obesity identified that planning ahead, social support, and intrapersonal changes (e.g. self‐confidence) can promote engagement in MRT. On the other hand, unplanned schedule changes, social pressures, and different intrapersonal factors (e.g., taste preference) can make engagement challenging.

Conclusions

Adolescents provided information on factors that supported or hindered their engagement in MRT, and themes were consistent with prior literature on health behaviour change. Overall, adolescents would recommend MRT to other teenagers who carry extra weight. Future research can use the rich information provided by adolescents with severe obesity to enhance and individualize treatment options.

Severe obesity in adolescents, defined as a Body Mass Index (BMI) ≥1.2 times the 95th percentile, is associated with significant morbidity and affects approximately eight percent of adolescents in the United States. ¹ , ² The mainstay of obesity treatment is lifestyle modification therapy; though for adolescents with severe obesity, this is often not sufficient to elicit clinically meaningful weight loss. ³ Therefore, some patients receive more intensive treatment, such as specialized dietary plans, adjunct pharmacotherapy, or metabolic and bariatric surgery. Regardless of the intervention, there is notable heterogeneity in response; that is, some individuals lose weight, yet others gain weight. ⁴ Due to the wide variation in responses observed in different interventions, there is an opportunity to understand what characteristics might be associated with certain adolescents experiencing more or less success with various interventions.

In pediatrics, few studies have evaluated predictors of weight loss response, and among them, results vary. ⁵ Motivation, self‐worth, and adherence may influence response to lifestyle modification therapy. ⁶ , ⁷ Additionally, early response to intervention is associated with longer‐term intervention outcomes. ⁸ Child eating disorder characteristics and parental psychopathology may contribute to worse outcomes. ⁹ , ¹⁰ Age and BMI have both been evaluated as possible predictors, but results differ across studies and no consistent patterns have been demonstrated. ⁵ Thus, factors that consistently predict adolescents' response to obesity interventions remain elusive. Qualitative methodology offers an opportunity to gather rich, individualized data that may elucidate contextual factors not before considered or not assessable via quantitative research methods. Themes illuminated from qualitative interviews can guide future qualitative and quantitative assessments for determining precision medicine approaches.

The primary goal of the current study was to understand the experience of adolescents with severe obesity participating in meal replacement therapy (MRT), with a focus on exploring unique biopsychosocial factors that could be evaluated in future studies as possible predictors of treatment response. A biopsychosocial model considers an individual's health to be comprised of a combination of biological characteristics, behavioural factors, and social conditions. ¹¹ MRT is a highly structured intervention including a prescriptive diet of reduced caloric content, which has been shown to be effective for short‐term BMI reduction in adolescents. ¹² , ¹³ In the current study, MRT included liquid shakes and pre‐packaged frozen meals that were provided to participants and totalled ~1400 kcals per day. In addition to this meal provision, participants were encouraged to independently add two servings of fruit and three servings of vegetables each day. The straightforward and standardized nature of MRT, yet varied individual response, lend itself well to assessing unique experiences from adolescents. Given the treatment‐resistant nature of adolescent severe obesity, gaining a better understanding of adolescents' individual experiences is important for improving treatment options and facilitating progress in precision medicine for pediatric obesity.

1. METHOD

1.1. Participants

Seventeen adolescents, ages 12–17, with severe obesity participated in this study (7 female; 10 male). All participants spoke English and were from a metropolitan area in Midwest United States.

1.2. Procedures

This study was an ancillary study to a larger randomized controlled trial that used an MRT run‐in phase prior to examining the effectiveness of medication support for weight loss maintenance. ¹³ MRT consisted of three liquid shakes and two pre‐packaged frozen meals per day (~1400 kcals per day), which were provided free to participants as part of the parent trial. Participants were encouraged to add two servings of fruit and three servings of vegetables per day. MRT lasted for 4–8 weeks, depending on when participants met their individualized goal associated with the parent trial. ¹³

For the current ancillary study, participants were recruited and interviewed at their final day of the MRT phase. Each participant completed a semi‐structured qualitative interview with the last author (ACG). Due to having just one interviewer and, therefore, limited availability, a convenience sample of participants from the parent trial was recruited and interviewed. Interviews lasted approximately 15 to 30 minutes. The interview protocol was comprised of semi‐structured, open‐ended questions, addressing participants' experiences of the meal replacement phase of the larger study (see Figure 1 for Interview Guide). All interviews were audiotaped and transcribed verbatim, and then reviewed to ensure accuracy.

FIGURE 1.

Semi‐structured interview guide

A phenomenological qualitative method was employed. This method explores how individuals understand and experience the world around them and make meaning out of their experiences. ¹⁴ For the present study, the phenomenon of interest is the experiences of adolescents with severe obesity who participated in MRT to promote weight loss. Through the exploration of similarities and differences between participants' experiences of engaging in MRT, the nature of this phenomenon can be understood.

To uphold trustworthiness in this study, five major criteria were followed, including credibility, transferability, dependability, confirmability, and catalytic validity. ¹⁵ The process of credibility, in which the researcher confirms the accurate identification and description of a phenomenon, was achieved through “honesty” (i.e. participation and withdrawal from study are completely voluntary) and “iterative questioning” (i.e. asking clarifying questions, paraphrasing) (p. 67). With respect to transferability, information regarding context and methodology is described here, while a detailed and accurate description of the research study's procedures and design ensured dependability. Confirmability was ensured by maintaining a detailed “audit trail” (p. 67) regarding how the data was gathered and analysed. Finally, establishment of catalytic validity, or “the degree to which research moves those it studies to understand the world and the way it is shaped in order for them to transform it, ¹⁶ ” was completed by debriefing with participants at the end of the interview. ¹⁵

1.3. Theoretical framework

The researchers employed the biopsychosocial model ¹¹ as a theoretical framework for this study. This model views an individual's health as a result of a blend of biological characteristics (e.g., appetite), behavioural factors (e.g. lifestyle and stress), and social conditions (e.g. family relationships and social support). Using this framework allowed the researchers to explore primarily psychological and social factors, which interact with each other as well as with biological factors, in adolescents with severe obesity who participated in MRT.

1.4. Data analysis

Data collected in this study was analysed using Interpretive Phenomenological Analysis (IPA). ¹⁷ IPA is consistent with the phenomenological methodology of this study, since its approach involves a detailed examination of participants' experiences and concerns itself with participants' perceptions of the phenomenon. ¹⁸ Using NVivo software, the first (SK) and last author (ACG) read each transcript to become familiarized with the account. Both created initial notes that were turned into focus points, and later themes and subthemes. If there was disagreement regarding accuracy, a discussion ensued until a consensus was reached. This analytic process was completed for each participant, after which the researchers searched for patterns across transcripts. Similarities and differences that emerged between transcripts were examined. ¹⁹ ACG and SK are both white women between 30 and 40 years old, representing two nationalities, American and Canadian, respectively. ACG and SK are psychologists; ACG focuses her clinical practice and research on pediatric obesity. ACG is a faculty member and SK was completing a 2‐year post‐doctoral fellowship in neuropsychology at the time of data analysis.

2. RESULTS

Based on individual interviews with adolescents with severe obesity, three overarching themes emerged representing psychosocial factors that were central to their experience with MRT: (1) scheduling and planning, (2) social support and pressure, and (3) intrapersonal factors.

2.1. Scheduling and planning

Most participants reported that creating a schedule, such as eating three meals and two snacks per day, provided them with increased structure for their day, thereby reducing their likelihood to consume food outside of their prescribed meal plan. For instance, one participant commented, “I think the set meal schedule helped a lot, because then you're not sitting there eating half a bag of chips at a time and drinking a Mountain Dew every couple of hours.” Participants also generally found that the added structure of attending school helped them follow the MRT‐specified plan. For instance, “Usually [on] weekdays, when I had school, you don't have time to do it—like eat the other food [outside MRT]. I'd just eat it in the morning. You get back home and you eat your food.” Further, many participants discussed that being on an MRT plan made them more thoughtful about when they would eat amidst school, extra‐curricular activities, and other responsibilities. As one participant recalled, “I also had football, so I just brought a protein shake and just had it after I was weight training.”

In addition to creating a schedule, participants reported that they engaged in planning behaviours to follow the meal plan. More specifically, participants had to think about how to prepare their food in certain settings, and then made arrangements to heat their meals. For example, “I have a social worker, and they have a microwave in their office, so I would just warm my food up and go down to the lunchroom.” Other planning behaviours included packing their lunch the night before school or planning meals when visiting relatives' or friends' homes.

When participants' scheduling or planning did not go accordingly, and they were unable to eat an intended meal or shake, most participants reported that they made healthy food substitutions. For instance, “I was at the mall, and I didn't eat anything all day, and [my mother] wanted to take me out to eat. I did order a salad.” Another stated, “One time, I was up at a cabin at that time, so my whole family, they were eating Chex mix, and I'm eating fruits and stuff. It felt good knowing that I was trying.”

On the other hand, some participants described their difficulty in adhering to the meal plan while at an all‐day extra‐curricular activity or when attending a week‐long camp. Furthermore, several participants reported that they struggled to eat only MRT foods when attending special occasions (e.g., parties, weddings, holiday meals). For example, “When we're celebrating, and you just have a little bit ‐ and then you want more and more. It's hard not to eat the food.”

2.2. Social support and pressure

Social Support. Many participants described that their parents, siblings, and close friends were a great source of encouragement and support as they followed the MRT meal plan. In some participants' families, adjustments were made to what was eaten in the home, such as offering healthier options at mealtimes or reducing the amount of food in the home that adolescents described as tempting (e.g., favourites that were not part of the MRT plan). For example, “My mom tried really hard to eat similar meals to what I was eating and also changed my family's portion sizes, [so] kind of similar to what mine were. And she made like a lot of vegetables that I could eat the same vegetables that my family was eating, without sauce.” Another participant stated, “They try to make healthy dinners, so I don't feel like the only one who has to have something healthy. And then throwing out junk food, so I don't feel tempted.” In a few instances, participants reported that their parents changed their own diet, further motivating each other to achieve their respective goals. In addition to changing their food intake, a few participants' parents supported their children by engaging in physical activity with them, such as going to the gym together. An example includes, “I usually go to the gym with [my dad now], so he would try to push me to go with him a lot and [before it was] not as much.”

Further, participants stated that in addition to parents adjusting their behaviour related to food and physical activity, they were also more overt in their encouragement. In other words, many parents verbally expressed their support of participants' efforts to adhere to the meal plan and offered tips or gave reminders about some of the tasks associated with the plan. As one participant stated, “My mom, she's pretty supportive about it…I'd start eating [mindlessly] sometimes, and she'd [say], “Aren't you on the food plan?” She'd point it out or just remind me or encourage me, ‘make sure you're doing it’.” Although a few participants found their parents' reminders to be “annoying,” they reported benefit from the overall verbal reinforcement their parents offered them during MRT.

Outside of families, participants found that their teachers or some friends also offered support. For example, several participants stated that their peers offered words of encouragement or made positive comments about their appearance. As one participant described,

“There were times when I kind of just wanted to quit and didn't want to do it anymore, but [my friends were] the ones that encouraged me, because they told me how much better I would feel after I lost weight instead of being stuck where I am.”

Social Pressure: Most participants also reported that they were faced with “temptations,” or non‐MRT foods, that were being made or eaten by their families or friends. More specifically, family members would bake desserts that the participant could not partake in, or friends would offer snacks at lunch. As one participant described, “Since my whole family wasn't doing it, it was kind of hard not to—like when they made little cookies—it was hard to not have a tiny bit. So that was probably the hardest part about it.” Similarly, some participants noted that it was harder for them when family members did not change their own eating habits and ate unhealthier meal options at dinner or when their friends invited them to eat at a fast‐food establishment. One participant explained, “My family always ate whatever they wanted, like junk and pizza. I mean, my mom did exercise with me—that was helpful. But like their eating habits, they were the same.” Another stated, “My friends would go to Taco Bell and invite me, and I would have to say no because I was trying to do this meal plan. But then I'd eventually go to Taco Bell anyway.”

2.3. Intrapersonal factors

2.3.1. Intrapersonal growth

In addition to having external support, participants reported that they noted several cognitive, physical, and emotional changes as they partook in MRT. In terms of cognitive changes, some participants described surprise in their ability to follow their meal plan. For example, “This whole thing taught me about discipline, because, my family, they would still like eat out and get McDonald's, and I would still eat my meals and my drinks.” Other participants discussed getting into a “mindset” and feeling motivated to stay on track in order to achieve their goals. For example, “I just know that I wanted to help myself like feel better, so I really wanted to stick with it and make sure that I was actually helping myself.” Another participant aptly stated,

“You have to have the mindset to actually want to [stick to the plan]. Otherwise, there's no point of even doing it. You have to want to lose the weight. You have to have the motivation to get up and actually work out and eat smaller portions and drink your shakes.”

In addition, most participants stated that they noted physical changes in themselves, including increased satiety, weight loss, increased level of energy, and decreased shortness of breath and somatic complaints. For instance, one participant described, “I just have a lot more energy because prior to this diet, I was 285 [pounds], and now I'm down to 243. It's just like getting a 40‐pound rucksack off your back and you just feel a lot better.” Additionally, participants stated having pre‐portioned meals and shakes helped them get used to eating smaller portions. This, in turn, led to feeling full or satiated, and reduced their likelihood of snacking. For instance, “What I liked was that [the meal plan] helped to portion my foods, so I wasn't overindulging, and I wasn't getting too full to where I was feeling sick.” Moreover, when they were unable to follow the intended MRT‐plan, participants consumed smaller portions of food than prior to their participation in MRT. For example, one participant stated, “Over at my buddy's house, I had two pieces of pizza because we ordered Domino's. But I limited myself. I could eat a whole pizza if I wanted to.”

Further, several participants reported that their cognitive and physical changes also contributed to changes in their overall emotional functioning. More specifically, some participants described notable improvements in their mood, level of anxiety, and self‐confidence. As one participant explained,

“I guess I've been [happier] about myself just because I'm trying [to lose weight] and knowing the fact that I'm trying to make myself healthy makes things seem better. I'm not as afraid and self‐conscious to change [during gym class]. I mean, I'm still self‐conscious, just because I don't like the way I look and I don't like other people seeing how I look, but the fact that I've been doing those things is just making things easier, knowing that I'm losing weight and I can start going down in sizes of clothes.”

2.3.2. Intrapersonal challenges

Some participants expressed their dissatisfaction with MRT, often related to intrapersonal factors of hunger drive and taste preference. Participants reported disliking the limited variety, blandness, and/or taste of the meals or shakes. For example, one participant stated, “I didn't really like the meals—they didn't taste like real food, it just didn't taste good. I liked the shakes, but the meals I didn't really eat.” Another recalled, “Sometimes, [the meals] didn't sound good. I just wanted fresh‐cooked meals, like homemade ones. I wanted something else besides the exact same thing every day.” In response, many participants described substituting or augmenting their meals helped decrease the monotony of eating the same meals, and adding flavours reduced the blandness of the food. For example, one participant explained, “You get Crystal Light and this sparkling water, and you just mix them together and it tastes like pop. [Or] getting zero‐calorie hot sauce to put on your meal.”

3. DISCUSSION

Through individual interviews with adolescents with severe obesity, three psychosocial themes emerged regarding participation in MRT: (1) scheduling and planning, (2) social support and pressure, and (3) intrapersonal factors. Specifically, adolescents reported that planning ahead, social support, and intrapersonal changes such as increased self‐confidence, promoted engagement in MRT. Conversely, unplanned schedule changes, social pressures of non‐MRT foods, and unique intrapersonal factors including taste preferences, made ongoing engagement challenging. These broad themes align with prior literature regarding health behaviour change, as described below.

Scheduling and planning are specific skills in a larger set of skills and abilities referred to as executive functions. Executive functions are higher‐order cognitive abilities needed to carry out goal‐directed behaviour, and include a variety of skills (e.g., flexible thinking, planning, inhibition). Stronger executive functioning is positively associated with obesity treatment outcomes, ²⁰ though the directionality of these relationships and possible mediating variables are not well understood. Importantly, executive functions are still developing during the teenage years. In this study, adolescents reported that being able to transition into MRT (i.e., be flexible) and being able to plan were essential to successful engagement. Some participants found that the pre‐specified structure of MRT helped them determine how much and what to eat, thus seeming to reduce the burden on executive functioning. However, others found it challenging to plan to have meal replacements ready in new environments (e.g., at school or friends' homes), seemingly increasing the demand on executive functioning skills. Because executive functioning skills are developing in adolescents, environmental supports through parents, educators, and medical providers are often needed to support health behaviour change. Thus, providers should assess and respond to the specific executive functioning needs of adolescent patients when determining obesity treatment plans.

Related to supportive environments, adolescents identified social influence as both a promoter and barrier to their engagement with MRT. Social support for health behaviours is associated with weight loss and maintenance in various interventions ²¹ , ²² , ²³ and results of this study revealed the same for MRT. Adolescents identified that having peer, family, and educational support to follow the meal plans helped them stay engaged with MRT. However, overt (e.g., invitations to restaurants) or covert (e.g., having favourite, non‐MRT foods in the house) suggestions to not follow MRT guidelines by family and peers was a hindrance to them remaining engaged with the plan. Adolescence is a unique time of development where teens are navigating increased independence from family members and highly value the opinions of their peers. At the same time, teens continue to rely heavily on family influence. Therefore, in treating adolescents, it may be beneficial to specifically assist teens in identifying both familial and peer allies for health behaviour change, as well as provide them strategies to successfully navigate or adapt their plans in the face of social pressures.

In reviewing intrapersonal factors, several participants identified the importance of being in the right “mindset” or being motivated to make health‐related behaviour changes. These adolescents were essentially describing that individual readiness for change was a critical component to their success, and a feature they believed others would need to successfully participate in MRT. This is consistent with the idea that patients need to be in an appropriate stage of change to implement new health behaviours. Guidelines for treating obesity suggest the use of motivational interviewing to support readiness to change, ²⁴ , ²⁵ and reports from adolescents in this study support that recommendation. It may be beneficial to incorporate motivational interviewing and/or assessment of readiness prior to any new treatment strategies, even if in the context of ongoing intervention (e.g., introducing a new dietary approach or adjunct intervention to an established treatment plan). Furthermore, adolescent interviews highlighted the need for the adolescent specifically to be motivated, not just parents, suggesting the need to assess readiness for change from both parents and teens in a clinical setting.

Within discussions of motivation and “mindset,” participants reported that they demonstrated improved discipline and became aware of their own self‐control. While the participants described this as a positive aspect of participating in MRT, the specific language used warrants reflection as it may be indicative of obesity bias. Adolescents' description of their path to weight loss primarily through their own “discipline” or “self‐control” may stem from a misguided assumption that carrying excess weight is fully within the control of oneself, ²⁶ , ²⁷ rather than appreciating the multitude of biological, psychological, social, and environmental factors that contribute to obesity. ²⁸ , ²⁹ , ³⁰ Prior literature indicates that adolescents view weight status as controllable, and that adolescents' belief that weight is controllable is associated with obesity bias. ³¹ As such, participants in our study that discussed the “positive” aspect of better self‐control or discipline are adolescents that may be experiencing obesity bias. Indeed, if these same participants had trouble following a treatment plan or experienced weight stabilization or weight gain, the associated description would likely be that they lacked discipline or self‐control. Therefore, in practice, monitoring for this individualized and potentially blaming language may present an opportunity for individual self‐reflection on internalized weight bias and education on the broad range of factors that are known to influence weight status that extend beyond individual choices.

Finally, as an intrapersonal barrier, several adolescents commented on the flavour and limited variety of meal options. While some participants found ways to increase variety within the specified meals (e.g., adding seasoning), MRT may be a good fit for participants who are less driven by craving or taste and instead struggle primarily with awareness of portion size. Alternatively, as an adjunct to MRT, it could be beneficial to help patients find strategies to tolerate limited food variety. Indeed, limited food variety can promote better weight management, ³² so tolerating this restricted range could be an important aspect of success.

In the current study, adolescents with severe obesity provided rich, qualitative information about their experience with MRT. However, one limitation of the current study is that themes were not able to be studied in relation to weight change outcomes. To continue to move towards precision medicine for adolescent severe obesity, an area for future study is to determine if these themes lead to differentiated treatment outcomes for patients participating in MRT. Another limitation of the current study is that we focused on a specific sample (i.e., adolescents with severe obesity) and a specified treatment, limiting transferability. It is unclear if different themes would emerge for individuals of differing ages or without severe obesity, or if the themes would differ for other treatment modalities.

In summary, the themes identified through the qualitative interviews regarding MRT were consistent with prior research regarding health behaviour change. In terms of MRT, readiness to change as well as a family, peer, and educational support may assist adolescents in engaging in MRT. Some adolescents may need additional support to follow MRT plans, such as assistance with executive functioning skills, combating family/peer pressure, and tolerating a restricted variety of food. Overall, when asked, adolescent participants reported they would suggest MRT to peers who carry extra weight.

AUTHOR CONTRIBUTIONS

Sarah Khayutin was responsible for data analysis, interpretation of results, and drafting the manuscript. Aaron S. Kelly, Claudia K. Fox, and Justin R. Ryder were involved in protocol design and review, data interpretation, and providing feedback on the manuscript. Amy C. Gross was responsible for leading the project, protocol design, data analysis and interpretation, and manuscript writing and review.

CONFLICT OF INTEREST

Sarah Khayutin, Claudia K. Fox, and Amy C. Gross have no relevant conflicts of interest. Aaron S. Kelly engages in unpaid consulting and educational activities for Novo Nordisk, Vivus, Eli Lilly, and Boehringer Ingelheim; receives donated drug/placebo from Vivus for an NIDDK‐funded clinical trial. Justin R. Ryder receives a donation of drug and placebo from Boehringer Ingelheim.

Khayutin S, Kelly AS, Fox CK, Ryder JR, Gross AC. Opinions from the experts: Experiences of adolescents with severe obesity participating in meal replacement therapy. Pediatric Obesity. 2023;18(2):e12986. doi: 10.1111/ijpo.12986