Rethinking family‐based obesity treatment

Emerging research in paediatric obesity has demonstrated that parental involvement in the weight management process can improve weight outcomes in children. Recent guidelines by the American Academy of Pediatrics note the importance of parent and family involvement in treatment. However, it is currently unknown if including the entire family in obesity treatment can supersede outcomes associated with participation of only one parent. Family Systems Theory (FST) provides the theoretical foundation for examining one's healthy behaviours as they exist within the context of their family, defined by family dynamics. This narrative review aims to reconsider prior definitions of paediatric family‐based management using the FST framework to be inclusive of family and household diversity and in doing so, inform research not only within weight management but also other domains of clinical care requiring family support or change. Applying FST to paediatric weight management highlights the link between family dynamics and paediatric obesity, demonstrating the association of dysfunctional family dynamics with more severe obesity. While family‐based weight management remains the gold standard for treatment of paediatric obesity, more investigation is needed in expanding family‐based interventions to impact entire families and potentially improve outcomes more broadly for overall family health and wellbeing.


| INTRODUCTION
Obesity prevalence remains unacceptably high, and during the COVID-19 pandemic, obesity appears to have worsened. 1Access to evidence-based treatment for obesity is increasingly recognized as critical in preventing unsafe, self-directed dieting behaviours. 2,3cently, the American Academy of Pediatrics (AAP) released the 'Clinical Practice Guidelines for the Evaluation and Treatment of Children and Adolescents with Obesity' (CPG), updating and summarizing the evidence that have advanced to the point of being treatment guidelines (vs.expert recommendations). 4The CPG reviews the evidence behind behaviourally based treatment of obesity, and features newer medications, bariatric surgery and targets of behavioural change that are making headway in improving the health and weight status of individuals affected by excess weight, yet the majority of youth with obesity are not receiving evidence-based care, and effective outcomes from weight management requires a substantial time commitment from families and health care providers. 5 youth, it is recognized that the inclusion of family, particularly a parent, guardian or adult caregiver (for simplicity, referred to as parent herein), in the weight management process is of utmost importance. 6arting in the 1980s, and continuing through today, inclusion of a parent showed improved weight outcomes for children. 7,8Intuitively this makes sense, as children depend on their parents for food, housing, transportation and overall support.In addition, parents are the primary role models of health behaviours for their children, demonstrating and establishing eating and activity habits.Further, parents establish rules pertaining to meals, sleep schedules and media use, and direct the utilisation of health care.In fact, research has termed 'parents as exclusive agents of change', in which the parent participating in weight management alone is equally efficacious in addressing child weight as the parent and the child participating together. 9,10ile family-based treatment is considered the gold-standard for paediatric weight management, whole family participation is typically not being practiced.As any provider working with children will attest, typically only one parent attends clinical visits.This could be because of the diversity in family structures (multi-generational families, single parent households and blended families), dual-working parents or parents attempting to minimize time away from school and work.It is understandable and not surprising that all family members involved in caring for a child would find it difficult to attend the 26+ contact hours recommended by the United States Preventive Task Force to effectively treat childhood obesity. 4,5This raises the question, 'Is treatment truly family-based if only one parent is participating, without siblings and other adults important to the health of the child?'Many sentinel studies in this area clearly identify a participating parent (not parents, and typically women or mothers) and show positive outcomes, 7,8,11 but it is not known how other household members are engaged in health behaviour change, or their awareness that the child and identified parent are participating. 12,13It is currently unknown if including the entire family in treatment can improve child outcomes over and above outcomes associated with the participation of one parent, and if it could improve adherence to treatment plans and sustainability of changes made.Further, to what degree can entire families participate in a treatment programme, and would outcomes be improved if they would?
The goal of family-based treatment is to change the health behaviours of the entire family and not focus solely on the child with obesity, as that could potentially harm the child by making them feel excluded from normal family routines and heighten challenges of selfesteem and bullying/teasing within families. 4

| PAEDIATRIC OBESITY TREATMENT BECAME FAMILY-BASED
Medical writings on obesity in children from the 1940s can be easily found, 14 and probably even earlier with greater effort and older technology (microfiche).In the 1970s, more publications discuss obesity in children, [15][16][17] including one discussing using behavioural modification in treatment. 18With the increasing prevalence of obesity in the 1980s, more research and clinical approaches focussing on behavioural treatment of obesity can be seen from leaders in the field such as Wing, 19 Epstein, 20,21 Brownell, 7,22,23 Israel 8,24 and others.Much of this work began to define the role of parents and family in the treatment process.Israel et al. 24 and Graves et al. 25 studied parent roles in treatment, using parental problem-solving and training in parent management skills to successfully improve child weight.In addition to outlining the use of behaviour modification in treatment with Wadden, 23 Brownell et al. 7 demonstrated how including mothers in treatment with their children mattered, with mothers and children being treated separately (but in parallel) having greater success in weight loss than children alone and mothers and children together.The importance of parent involvement was solidified in Epstein and colleague's classic studies that had 10 years of follow up, demonstrating superiority of parent inclusion in treatment. 26,27Flodmark et al. 28 was also pursuing family-based treatment via family therapy (discussed later) during this same time, preventing the progression of severe obesity in children of 10-11 years of age.Lastly, Golan et al. 29 and later Boutelle et al. 30,31 studied having parents being the exclusive targets of intervention, with children not being involved in treatment.While this was primarily in younger children (<12 years of age), they demonstrated that parents were an important variable when approaching treatment in younger children.In an umbrella review of family-based weight management interventions, Chai et al. 32 again surmised the effectiveness of including family members, and highlighted strategies of parenting, role modelling and encouragement of healthy diet and exercise in whole families.
As the rising prevalence of obesity began being referred to as an epidemic in the 1990s, there was increasing focus on the best approaches of treatment.The AAP developed and published expert committee recommendations in 1998, 33 again in 2007, 34 and newly released Clinical Practice Guidelines in 2023, 4 which all referenced treatment being 'family-based'.While this is unlikely to be the origin of the term 'family-based' in regards to paediatric weight management, it is highly referenced in standard of care.In these expert recommendations and guidelines, the studies of Brownell, Israel and Epstein are referenced, explaining 'Clinicians should involve the family and all caregivers in the treatment programme', 33 including discussion of the importance of healthy parenting practices.The early work of the 1980s and 1990s demonstrating the inclusion of parents in the treatment process formed the basis of today's recommendations of including the family in treatment, focusing on family-level habits and not just on the habits of the child. 4visiting the original studies (Brownell, Israel and Epstein) in which the term 'family-based' are often referenced, readers may question if 'family-based' is an inclusive description if only a parent was included as the representative of the family.This is not a fault or error of prior research; as it is quite common for a parent to grant permission for the child to participate and then consent to participate themselves.It may be that these studies are more dyad-based (parent-child) in nature versus being family-based interventions.
While a focus on parenting, which was featured in some of the studies described, could impact a family, these were not whole-family interventions.Also, the focus within these studies, as is in clinical settings, was on family habits, not just the child's habits, relying on the parentchild dyad to transfer these clinical activities to the home environment.

| RIPPLE-EFFECT OF TREATMENT
There is evidence that parents who participate in paediatric weight management programmes benefit as well, with improvements noted in their health behaviours and weight, in addition to improvement in their child's weight. 11,31,35This is intuitive, as paediatric weight management trials and clinical programmes often utilize family-based approaches, and focus lifestyle changes on the entire family, not solely the child with obesity.
There is limited research with methodological challenges (i.e., short term and retrospective) which demonstrates that children with obesity whose parents are undergoing metabolic and bariatric surgery have improvements in weight, summarized in a recent review. 36There is far less, if any, evidence about changes in child weight and behaviour when parents are attempting non-surgical weight loss; a small feasibility study (N = 20) did show improvement in parent and child weight status with a commercial weight loss programme for adults at 8 weeks. 37A secondary analysis of parents participating in a weight management programme found their children with overweight and obesity overall had a decrease in their body mass index z-score, while children with a healthy weight had no change. 38ile there are no readily available studies exploring the effect of weight management on siblings, there are a few studies showing associations of siblings' weight and health behaviours in the general population but not in paediatric weight management programmes.Research led by Berge has noted weight and weight-related behaviour correlations between adolescents, their parents and siblings, finding greater correlation between siblings for some behaviours 39 ; if the siblings were discordant on weight, parents employed potentially harmful, restrictive feeding practices on the child with excess weight. 40,41In a mixedmethods study, they also found differential weight talk within households, with siblings and fathers using more negative talk about weight, including teasing. 42These studies highlight the need to broaden the scope of interventions to include the rest of the family, both to possibly improve outcomes and prevent harm (weight talk).
Overall, there appears to be some evidence of a 'ripple-effect', with weight management (adult-and child-focused) improving the weight and health behaviours of others in the family, but it is far from definitive.While including a parent and child in treatment is likely to impact the rest of the family, there are many mediating factors.As an example, a study in a paediatric primary care setting found that only 58% of parents discussed weight management visits with other family members, and the likelihood of that was associated with family communication quality. 13Including only one parent attending weight management visits with a child is often more practical and feasible, but broadly on parenting skills and family dynamics, or more narrowly on health behaviours.Of particular note in the review, the 1993 study of Flodmark et al. 28 is an example of successfully utilizing a family therapy approach, which Kitzmann and Beech classify as a broad focus on family functioning and parenting.Subsequent works by Flodmark, Nowicka and others have explored these deeper aspects of the family and obesity, with evidence of effectiveness. 44,45

| FAMILY DYNAMICS AND OBESITY
There has been some discussion and investigation into family assessment and paediatric weight management, noting the limited use of the family studies field in this area. 46Pratt and Skelton 47  considerations, and while clinicians may intuit some of these elements in a treatment visit, understanding their impact or influence on outcomes to date is unknown.There is some evidence that family dynamics and obesity in children are linked, with dysfunctional or impaired dynamics associated with more severe obesity, 48,49 and better family functioning associated with better outcomes after bariatric surgery. 50 a brief review of the available literature, poor family functioning was associated with unhealthy weight-related behaviours and a higher child weight status. 51While nascent, existing evidence does highlight the importance of family dynamics, and the potential importance it has in paediatric weight management.
While the focus on family dynamics has been presented as a new approach to consider, others have been pursuing since the early 1990s.As detailed earlier, Flodmark et al. 28 included family therapy in treatment.Nowicka and Flodmark 44 detailed their use of family therapy in the treatment of childhood obesity, called Standard Obesity Family Therapy (SOFT), which focused more broadly on parenting, family functioning and overall family dynamics, noting the limited number of follow up sessions (three-to-four a year) and focus on family interactions.Their literature review in 2008 supports the use of family-focused treatment, 52 including the use of behavioural interventions (cognitive behavioural therapy, etc.), and also highlighted the same Kitzmann and Beech review where the majority of obesity interventions focused on family health behaviours versus family function. 43While they have had a long-standing platform of focusing on family dynamics and obesity, there remains little mention of these treatment approaches in the new AAP CPG, 4 reflecting the need to integrate this evidence into current interventions.

| FAMILY SYSTEMS THEORY
FST 53,54 has been used to inform family assessment and treatment (most notably assessments based on the McMaster Model of Family Functioning 55,56 ).FST is conceptualized and applied to clinical research and treatment in different formats (i.e., solution-focused therapy, cognitive and behavioural family therapy), but at its core, recognizes that individuals must be understood within the context of their family (Table 1).
The complexity of the family system is understandably difficult to apply to everyday clinical settings, but does have important ramifications for paediatric weight management in the context of family-based treatment.In particular, it can provide a framework for understanding the family represented by the likely scenario of a parent-child dyad attending treatment visits.Providers should ask questions regarding roles, relationships, communication, rules and structure within the home.Pratt and Skelton 47 discussed an FSTinformed approach to assess the families in paediatric weight management, which includes inquiring about household structure, rules, communication, behavioural control, responsiveness, involvement, strengths and barriers to change.Nowicka and Flodmark note their SOFT treatment is derived from FST. 44 A systematic review of randomized trials only found two studies utilizing FST, with mixed results compared to traditional family-based therapy. 57

Based on the review on family-level interventions in paediatric weight
management by Kitzman and Beech 43 and Sung-Chan et al., 57 it is not possible to determine if intervening with families beyond the participating parent-child dyad has an equal or increased positive effect to the child and other family members.However, other fields can offer some evidence about the benefits of extending treatment beyond the parent-child dyad, such as in the treatment of substance use disorders 58 and type 1 diabetes, 59 in which including individuals beyond the parent-child dyad led to improved outcomes.
Family meals, or meals eaten together at home with other family members, are an important family-level behaviour with inherent interpersonal interactions that should be considered in relation to children's weight.Several studies, systematic reviews and meta-analyses have demonstrated positive associations between higher frequency of family meals and healthier children's weight, dietary behaviours and practices, [60][61][62] although the consistency and quality of the evidence T A B L E 1 Brief summary of Family Systems Theory. 45,46mily is a complex system Members of the family system are interconnected, and must be viewed as a whole The behaviour of the system interacts with the environment as a feedback loop The family determines who are members and sets boundaries Families strive to maintain equilibrium, although they must evolve and change Subsystems exist within the larger system, and can influence the larger family system There are higher and lower levels within the family system, with higher orders causing change in lower orders varies. 63Further, the effects extend beyond nutritional habits, and positively influence other aspects of well-being, such as decreased substance use, violence, sexual activity, 64 and mental and behavioural health issues 65 and better family relationships. 66These findings speak towards a broader, simultaneously positive effect by identifying areas of family-level behaviours and dynamics linked to obesity, and intervening on those areas to potentially improve the health of the entire family, a different kind of 'ripple effect'.

| REVISITING FAMILY-LEVEL INTERVENTIONS
Current family-based interventions provide evidence of positive impacts on child weight and health. 4,5Revisiting the early, formative literature, and the disparate studies accounting for family members in the household beyond the parent-child dyad, it could be worth exploring efforts to broaden interventions to account for and impact the broader family system.Briefly summarizing: • There is some evidence of a 'ripple effect' in which children of parents pursuing weight management (particularly undergoing metabolic and bariatric surgery) and siblings of children in weight management improve their weight.
• Most evidence in paediatric weight management is based on parent-child dyads only.
• Parents of children who participate in family-based, paediatric weight management may improve their own weight (and potentially health), which often is precursory to positive changes in their child's weight, indicating a family intervention, or a different form of the 'ripple effect'; including additional family members may potentially magnify changes and impact.
• Evidence exists that family dynamics are associated with severe obesity in children.
• There is a theoretical basis for focusing on the family system and integrating behavioural and family systems theories into paediatric weight management.
There is a practical case to be made for extending interventions There are many practical challenges to this concept.More research is needed to determine best approaches, and in particular, which aspects of the family system have the potential to make the greatest impact on health and weight, which could differ between parent and child.This would require a move away from 'weight-loss' in a family, which can be quite different between adults and children, and a move towards health behaviour improvement, with weight change being a favourable side effect of more healthful behaviours in those with obesity (long-term goal).This, however, could prove frustrating for a parent or adolescent desiring weight loss (although much weight that is lost with short-term efforts are eventually regained).As with any health behaviour, and in particular weight management interventions, more focus is needed on safety, ensuring disordered eating and unhealthy weight control behaviours do not arise.However, recent expert guidelines assure that professional, behaviourally based weight management programmes protect against disordered eating in children. 4 When only parent-child dyads are included in treatment, clinicians are typically only observing the interactions of that dyad and relying on their self-reports of other household members' behaviours.With questioning, more can be learned about the family and their health behaviours, particularly if others in the family have obesity or are attempting behaviour change.Many factors within a family could mediate the behaviour change process: what role does each family member play (who cooks, who shops for food, do they have similar parenting styles when it comes to discipline, schedule and rules); are there special circumstances that would impact families making changes, such as another family member with medical or behavioural issues (celiac disease, inflammatory bowel disease and autism spectrum disorder); what are work and school schedules; how is information from clinic/programme visits relayed to the rest of the family; what is the readiness to change of each family member; does the family have relationship or interpersonal challenges that could make changes in routines difficult; and how is treatment implemented differently within households based on family structure (i.e., one parent vs. two parents vs. blended families)?There are many aspects of the family and household that are important to consider when initiating paediatric weight management.The overall purpose of this narrative review is to reconsider prior definitions of paediatric family-based weight management to be inclusive of the diversity of families and households that children reside.This type of inclusion should encompass additional household family members in treatment, consider the interpersonal dynamics among them that affect children's outcomes, and finally, determine if treatment has potential 'ripple effects' or benefits to family members' health status.Re-evaluating how families are assessed and included in clinical care settings may improve treatment approaches, identify new areas of intervention and personalize and individualize care for families.Exploration of the family system in clinical care may inform research in these areas to test ideas and assumptions.Further, it could impact clinical care outside of weight management, in any situation that requires changes family support or change.
more effort could be made to facilitate information spread to other family members and to support the change process from clinic to home, as that 'ripple effect' is now dependent upon the family members attending clinic.An interesting review by Kitzmann and Beech 43 assessed 31 family-based obesity studies, sorting them into categories based on having broad (parenting skills or family functioning) or narrow (nutrition and exercise) parent/family behaviour targets.Study designs and results were varied, leading the authors to ask how best to involve the parents in treatment, and if interventions should focus discussed integrating Family Systems Theory (FST, discussed below) into familybased paediatric weight management to include the routine assessment of family dynamics along with health behaviours.Many aspects of family dynamics are pertinent to a child's health behaviour changes, with family dynamics generally referring to relationships, interactions, roles and environment within a family.Often in paediatric weight management, dynamics are assessed through parenting styles, family functioning, family communication and family stress.Family dynamics (parent-child, sibling-sibling, parent-sibling, etc.) are important to consider, as dysfunctional relationships can lead to a negative household environment, making changing of routines and schedules more contentious.According to FST, family members should be flexible and adaptable to changing behaviours, rules and communication to adopt healthier behaviours to support the child in treatment.In clinical settings, whether working with a parent-child dyad or with multiple family members, relationships and communication are important to focus on entire families, as more individuals can be impacted by a single intervention, versus separate interventions for children and adults.As seen in Golan and Boutelle's parents as exclusive agents of change, intervening with a parent can improve the weight of a child.30Conceptually combining that with the influence we see on parents' weight when participating with their children, and the improvement in child weight and behaviours when adults undergo metabolic and bariatric surgery, there is the potential to improve the health of all family members in the household.Many evidence-based programmes, such as the Diabetes Prevention Program67 or Help Prevent Diabetes (HELP-PD),68 could be adapted to target the family system to improve family health habits, or adapting effective paediatric weight management programmes to better extend the 'ripple effect' to other members of the family.It could be argued that existing paediatric weight management programmes, classified as family-based, already focus on family health habits, as evidenced by reports showing improvement in parent and child weight.But do these behaviourally based programmes, which use change techniques such as motivational interviewing, cognitive behavioural therapy, tracking and monitoring and goal setting, account for the complexities of the family system?Or for the complex nature of family dynamics: communication, parenting, family functioning, stress, rules, routines and schedules?While this may complicate a treatment approach, it also has the potential of spillover effects as seen in family meals, improving overall wellbeing and a decrease in other obesity-related and psychosocial risk factors.An approach that includes the entire household also has the potential for increasing family-centeredness of approaches, where standard health behaviours (consuming more fruits and vegetables, increasing exercise) may not implemented, but families are empowered with individualized, personalized ways to determine what can be done to improve their family dynamics in a way to optimize their health behaviours.
Other logistical challenges include finding ways to practically include additional family members in the household based on school and work schedules.Additionally, family members may have differing levels of interest in participating in a family-based treatment programme and readiness to make behavioural changes.More research is needed into inclusion via telehealth and mobile applications, group-based family sessions and opportunities for families to participate in after-hours or weekend programmes.There is also the possibility to focus on 'parents as exclusive agents of change' interventions, to better incorporate family-level interventions (i.e., improving family communications, relationships and schedules) to improve health behaviours of the family through the parents.Cultural adaptations of family-based treatments are an opportunity for innovation, but also require deep knowledge of families' traditions and background, as well as greater diversity in the teams providing care.A systematic review in 2017 of prevention interventions noted the limited number of studies targeting diverse populations, including non-traditional families,although there were several focused on Hispanic and low-income families,69 while a more recent study found some disparities in familybased treatment by race and ethnicity.70Finding ways to include extensions from paediatric weight management into families' local communities may prove more advantageous, by engaging additional family members where they already are, such as local parks, social clubs, religious services and schools.Using community-engaged approaches in developing interventions will likely improve and facilitate cultural adaptations, address the gaps in the literature and advance health equity, as the recent AAP CPG notes the lack of evidence in this area. 48 | CONCLUSIONS Family-based weight management remain the gold standard for the treatment of paediatric obesity, in combination with advances in bariatric surgery and pharmacotherapy.With the new AAP CPG, there will be increasing interest and efforts to bring evidence-based treatment to children and families.There is the potential to extend these family-based interventions in a way to impact entire families, possibly improving outcomes for the child, siblings and parents, impacting families' weight, health and wellbeing through more intentional focus on family dynamics and function.More research, experience and collaboration are needed to investigate these possibilities.