The impact of Allied Health Professionals on the primary and secondary prevention of obesity in young children: A scoping review

Allied Health Professionals (AHPs) have the capacity to promote healthy behaviours in young children through routine ‘contact points’, as well as structured weight management programmes. This scoping review aims to evaluate the impact of AHPs in the prevention of obesity in young children. Databases were searched for relevant evidence between 1st January 2000 and 17th January 2022. Eligibility criteria included primary evidence (including, but not limited to; randomized controlled trials, observational studies, service evaluations) evaluating the impact of AHPs on the primary and secondary prevention of obesity in young children (mean age under 5 years old). AHP‐related interventions typically demonstrated improvements in outcomes such as nutritional behaviour (e.g. lower sweetened drink intake), with some reductions in screen time. However, changes in weight outcomes (e.g. body mass index (BMI) z‐score, BMI) in response to an AHP intervention were inconsistent. There was insufficient data to determine moderating effects, however tentative evidence suggests that those with a lower socioeconomic status or living in an underprivileged area may be more likely to lose weight following an AHP intervention. There was no evidence identified evaluating how AHPs use routine ‘contact points’ in the prevention of obesity in young children. AHP interventions could be effective in optimizing weight and nutritional outcomes in young children. However, more research is required to determine how routine AHP contact points, across the range of professional groups may be used in the prevention of obesity in young children.

respiratory conditions (e.g. sleep apnoea and asthma) 4,5 and digestive diseases (e.g. non-alcoholic fatty liver disease). 6 There may also be subclinical alterations in relation to cardiovascular (e.g. cardiac morphology and function) 7,8 and metabolic outcomes (i.e. physiological indicators of metabolic syndrome) 9 in children and adolescents living with obesity. Obesity in childhood may also track into adulthood, 10 and manifest into non-communicable diseases such as type 2 diabetes and cardiovascular disease. 11,12 As such, the prevention of childhood obesity is a public health priority. Children under 5 years are undergoing a key period of development in which they are constantly learning and adhering to new behaviours, which provides an ideal opportunity to promote healthy weight-related behaviours, potentially preventing the incidence of obesity later in life. 13 All healthcare professionals and organizations have a role to play in promoting the health and wellbeing of the population. In England, this is guided by the 'Make Every Contact Count' (MECC) approach to behaviour change, in which every interaction between healthcare professionals/organizations and the public should be seen as an opportunity to engage in conversations regarding health. 14 Included in this are Allied Health Professionals (AHPs), who work across several sectors related to health, social care, education, justice, voluntary sector, housing, academia, business and private practice. These professionals have a strategic role in the promotion of health and wellbeing in the early years. 15 The contact points between AHPs and children under 5 years old vary considerably in the type of care, and are primarily coordinated via health visitor referral, where deemed necessary. However, these contact points may represent an ideal opportunity to MECC and promote a healthy lifestyle. In addition, many AHPs have the skillset to both design and implement weight management programmes outside of routine contact points, which may be a useful strategy in the prevention of childhood obesity. As such, it is necessary to evaluate the role of AHPs in the prevention of childhood obesity in young children. These findings may be useful for guiding both policy and practice. As such, this scoping review aimed to evaluate the evaluate the impact of AHPs in the prevention of childhood obesity in young children.

| METHODS
This protocol was prospectively registered on the Open Science Framework (https://osf.io/2kdr6/). The methodological approach to this scoping review was underpinned by the JBI reviewers manual 16 and PRISMA-ScR guidelines. 17 This work was commissioned by the Office for Health Improvement and Disparities (OHID) to inform UK policy and practice. Subsequent findings are considered and framed with a UK context and similar healthcare systems in mind. Despite this, any findings and associated learning from this study are applicable in multiple international contexts. Children's Fund, WHO and World Bank estimates. 18 No language restrictions were applied during the searches to overcome any indexing errors, however English language was an inclusion criterion for this review. Searches were conducted using a combination of synonyms, wildcards and relevant MeSH terms for population, weight, allied health professionals and interventions. The full search strategy can be found in Data S1. Grey literature databases, policy and guidance documents, as well as other online resources were searched for evidence.
Reference lists of relevant studies and review articles were screened to identify any further eligible studies.

| Eligibility criteria
The scoping review included any primary evidence (including, but not limited to; randomized controlled trials, observational studies, service evaluations) evaluating the impact of AHPs on the primary (i.e. recruiting children predominantly living with a healthy weight) and secondary prevention (i.e. recruiting children exclusively living with overweight/obesity) of obesity in young children with a mean age of under 5 years old. Additional eligibility criteria included: interventions/programmes/services related to one of the 14 AHP roles, as specified in the 'AHPs into action' strategy document published for 2017-2021. 19 These include: art therapy, podiatry, dietetics, drama therapy, music therapy, occupational therapy, operating department practice, orthoptics, osteopathy, paramedic practice, physiotherapy, prosthetics and orthotics, radiography (diagnostic and therapeutic) and speech and language therapy. Studies included child populations with a mean age under 5 years old to align with the early years foundation stage. 20  Exclusion criteria included: Systematic reviews, meta-analyses and narrative reviews. Evidence evaluating children who are exclusively underweight were excluded given the differing purpose of interventions/programmes aimed at those children experiencing 'failure to thrive'.

| Screening and data extraction
Titles and abstracts of identified papers were screened in duplicate by two independent researchers to evaluate eligibility. Full texts of potentially relevant studies were then retrieved and reviewed in duplicate for eligibility by two independent reviewers, with any disputes resolved by a third reviewer. Where multiple publications of the same intervention/study reported different follow-up durations and findings, all publications were included in the review. Where the most recent publication from an intervention/programme includes all follow-up time points (i.e. reporting data previously published, as well as new data), only the latest publication was included to avoid replication of data in the present review. A standardized, pre-piloted electronic form (Microsoft Excel) was used to extract data. Using the template for intervention description and replication (TIDieR) checklist, 21 the data extracted included specific details about the participants, concept, context, methods and key findings relevant to the review questions. Data was extracted by one reviewer, with a subset (20%) checked for accuracy by a second reviewer (100% accuracy obtained).

| Data analyses and quality assessment
Data were analysed via narrative synthesis and tabulated results.
Primary outcome data included a weight outcome (BMI, BMI z-score, prevalence of obesity), as well as other obesity-related behaviours (nutrition, physical activity, screen time) in response to AHP interventions and/or routine 'AHP' contact points. Nutrition (e.g. fruit and vegetable intake, sweet and savoury snack intake), physical activity (e.g. step count), and screen time (e.g. the amount of sedentary time watching TV, playing on iPads, electronic games devices, etc.), were extracted due to their role in the development of obesity and associated non-communicable diseases. 22,23 Where possible, a variety of moderators such as ethnicity, socioeconomic status, geography, and weight status were described narratively to determine their influence on the effectiveness of interventions.
Due to the variety of study designs in the scoping review, the methodological quality of the studies was assessed using an adapted Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies 24 . Each study was assessed in relation to six criteria: selection bias, design, confounders, blinding, data collection methods, withdrawals and dropouts. Each component was assessed as 'weak', 'moderate' or 'strong'. If a study received a 'weak' rating for two or more components, it was judged to be 'weak' overall. If a study received one 'weak' rating and the rest 'moderate' or 'strong', it was deemed 'moderate', and those with no 'weak' ratings and at least four 'strong' ratings, were deemed 'strong' overall.

| Study selection
A total of 2485 records were identified from searching MEDLINE, PsycINFO, CINAHL and ERIC databases. After duplicates were removed, 1653 records were screened based on title and abstract. A total of 1624 records were excluded and 29 full texts were retrieved for screening. Following full text review, five studies were identified as eligible for inclusion in the review. [25][26][27][28][29] An additional 12 studies were identified via citation searching of included papers and relevant reviews. [30][31][32][33][34][35][36][37][38][39][40][41] This number was higher than may typically be expected, largely due to an absence of terminology related to AHPs or AHPrelated roles within the title, abstract, key words and indexing of these studies. A total of 17 studies were therefore eligible for inclusion in this review. A PRISMA flow chart of the study selection process can be found in Figure 1. A list of records which were excluded at the full text stage and the reasons for this are included in Table S1.
No grey literature sources were identified for inclusion within this review via manual search. However, discussion with experts/ professionals in the area did provide access to an unpublished preliminary report on the 'Jump Start Tots' programme based in Ayrshire, Scotland. 42 In addition, AHP case studies were identified via the UK Royal Society for Public Health. 43 An unpublished conference poster was also provided that evaluated occupational therapist's perceptions of their role in the prevention of childhood obesity. 44 These documents did not meet the eligibility criteria for the present review but are considered within the discussion.
Follow-up duration ranged from 6 weeks to 3.5 years (mean = 15.9 months). Mean age of participants ranged from 6 days to 4.9 years. Overall, there was a mean of 48% boys and 52% girls included in this review.
Due to the different designs of included studies, there is some between study variance in the comparisons made regarding outcome variables (e.g. intervention vs. control group, pre vs. post). To optimize readability, the data are broadly described here, but exact comparisons for each study are detailed in Table 2.

| Weight outcomes
Of the 11 studies to report BMI z-score, seven studies reported no change, 25,26,29,32,33,35,40 and four reported a reduction in BMI z-score 30,34,36,38 in those exposed to the intervention. In the three studies that reported BMI-for-age percentile, one study showed no change, 28 one study showed a decrease, 39 and one study showed an increase in response to the intervention. 37 In the three studies that reported BMI, all studies showed no difference in response to the intervention. 27,31,41 Of note, of the 10 studies recruiting children irrespective of weight status (i.e. primary prevention strategies), two reported reductions in a weight outcome, 34,36,39 seven reported no change 25,[27][28][29]35,40,41 and one reported an increase in a weight outcome. 37 Of the two studies recruiting children living exclusively with overweight and/or obesity (i.e. secondary prevention strategies), all studies reported reductions in a weight outcome. 30,38

| Obesity-related behaviour outcomes
Of the 10 studies reporting nutrition-related outcomes, nine studies showed some improvement in eating behaviour, [26][27][28][29]32,34,37,38,40 whilst only one study showed no change. 30 Of the 12 studies reporting physical activity-related outcomes, nine studies showed no whilst three studies showed increases in physical activity. 31,37,38 Of the six studies to report screen time, three showed reductions in screen time in response to an intervention, 26,29,34 whilst the other three showed no change in screen time. 27,28,32 Of the studies to report other outcomes, four showed improvements in maternal feeding practice (i.e. the behaviour of the mother that influences children's eating), 27,29,33,41 one study showed improvements in gross motor skills 25 and one showed reductions in blood pressure. 38 Two studies showed no change in sleep-related outcomes. 27,29

| Moderating factors
Due to substantial heterogeneity in reporting, it was not possible to provide an assured narrative synthesis on the impact of sociodemographic characteristics such as ethnicity, geography or socioeconomic status.
However, individual studies provide included in this review provide some insight into the influence of socioeconomic status and weight status. In this regard, Jouret et al. 36 found that a multidisciplinary intervention in children who lived in underprivileged areas significantly reduced BMI zscore and the prevalence of overweight, whereas no change in these outcomes was observed in those children not living in underprivileged areas.
In addition, Klohe-Lehman et al. 37 conducted a weight loss intervention for mothers and determined the subsequent effects on the prevention of obesity in their infant offspring. They demonstrated that the children of mothers with less than a high school education were more likely to have a child whose BMI-for-age percentile decreased in response to the intervention, compared with mothers with partial college or college education.
With regards to weight status, Lanigan et al. 38 demonstrated that a multidisciplinary intervention significantly reduced BMI z-score and waist circumference in children living with overweight and obesity, but no differences were observed when recruiting children irrespective of weight status.

| Methodological quality of included studies
Twelve studies included within this scoping review were judged to be weak in relation to the quality assessment 25,26,[29][30][31][32][34][35][36][37]39,40 ( Table S4). This was largely due to the lack of blinding of participants and/or study personnel to intervention and/or research question, as well as a lack of evidence provided in relation to the validity and reliability of data collection tools related to BMI (i.e. stadiometers, scales).
Specifically, studies generally did not report validity and reliability measures of tools utilized, as would be expected to be deemed moderate or strong for the 'data collection methods' criterion. The remaining five studies achieved a moderate score for quality assessment. 27 There was insufficient data to determine definitive moderating effects, however some individual studies did suggest that those with a lower socioeconomic status or living in an underprivileged area may be more likely to lose weight following an AHP intervention. 36,37 These findings could be attributed to increased sensitivity to interventions in families with low socioeconomic status, due to reduced exposure to healthcare systems and obesity prevention information. 36 These findings are likely important given evidence which demonstrates an increased prevalence of children living with overweight and obesity in most, compared with least deprived areas. [46][47][48] These data also provide evidence to support the need to fight against health inequalities/disparities. Notably, there was no evidence evaluating how routine 'contact points' are used to prevent obesity in young children.
Findings from this scoping review somewhat contrast data from a large meta-analysis outlining 'moderate' to 'certain' evidence that a combination of diet and physical activity interventions (not exclusively AHPrelated) reduced BMI and BMI z-score in children aged 0-5 years. 49 The discrepant findings in this review may be attributed to the predominant use of primary prevention strategies (i.e. recruiting children predominantly living with a healthy weight). In such scenarios, maintenance of a healthy weight (i.e. no change in weight outcomes) is likely the optimal outcome.
There is tentative evidence to suggest that those studies involved in the secondary prevention of childhood obesity (i.e. recruiting children exclusively living with overweight/obesity) may be effective at reducing BMI zscore. 30,38 Interestingly, Brown et al. 49 demonstrated that single dietary or physical activity interventions alone did not alter obesity-related outcomes in children aged 0-5 years. This highlights the importance of a multidisciplinary approach to the prevention of childhood obesity. In studies identified through this scoping review, that did use multiple AHP roles (e.g. dietitian and physiotherapist), significant reductions in obesity-related outcomes were observed. 30,34 Some improvements in obesity-related behaviours were observed in children following an AHP intervention, particularly in relation to nutrition outcomes such as lower sugar sweetened snacks and drink intake. 26,32,34,37,40 These findings demonstrate the benefit of AHPrelated interventions beyond a weight outcome, as sugar intake has been identified as a risk factor for the development of overweight/obesity later in life. 50 The improvements in nutrition outcomes may be explained by the predominant use of dietetic expertise to design and implement interventions/programmes. Some improvements in screen time were also observed, 26,29,34 which has also been associated with a reduced risk of childhood overweight/obesity. 51 In contrast, more infrequent improvements were observed in physical activity. These inconsistent findings may be a result of minimal AHP input to the design of physical activity interventions. More widespread use of other AHPs such as physiotherapists and occupational therapists may improve the efficacy of these interventions and the associated outcomes.
Collectively, these findings suggest that AHPs may have an important role in promoting healthy behaviours and optimal weight management. Input from AHPs into the design and/or implementation of primary and secondary prevention strategies may contribute to reduced incidence of overweight/obesity in young children. This is of vital importance to public health given the potential development of sub-clinical disease in children living with overweight and/or obesity. 7,8 In addition, obesity may also track into adulthood and lead to the development of clinical disease such as type 2 diabetes. 10-12

| Implications for policy and practice
A whole systems approach to the prevention of childhood obesity warrants consideration. This approach encourages local stakeholders, including communities to come together, evaluate current practice and identify opportunities for change. Stakeholders then agree actions to bring about sustainable, long-term systems change. 52 The key steps in facilitating systems level change are outlined in Figure 2. A resource to inform local authorities on a whole systems approach to obesity prevention in the early years foundation stage has been detailed previously. 53  Intervention (pre vs. post) PA behaviour: $ Note: Where available, BMI z-score has been used as the preferable measure of weight. Where a study has reported a positive change in ≥1 nutritionrelated behaviour, this has been deemed an overall positive effect (") (e.g. " fruit intake). In addition, where a study has reported a positive change in ≥1 physical activity-related behaviour, this has been deemed an overall positive effect ("). Effect sizes were deemed directional when the CIs did not span zero. Detailed findings including all variables and comparisons are outlined in Table S4. BMI, body mass index; PA, physical activity; NR, not reported.
staff and/or implementing healthy lifestyle interventions/programmes in a childcare setting. However, it is important to consider these interventions/programmes holistically when integrating into a whole systems approach. 52  Public Health in 2015. 55 The requirement for AHP training is further highlighted in a recent conference poster evaluating occupational therapists' perceptions of their role in the prevention of childhood F I G U R E 2 Whole systems approach to obesity 52 obesity in Wales. 44 Occupational therapists often lack the confidence to discuss obesity with children and families, but also feel that BMI is a confusing measure for obesity in children and therefore struggle to identify when a child is living with overweight or obesity. 44 Occupational therapists also feel they could work as part of multidisciplinary teams (e.g. specialist obesity teams, public health or community) to tackle childhood obesity. These observations are supported by a recent review which found that primary care providers inconsistently implemented recommended practices. 56 Barriers and enablers were identified at the provider (i.e. lack of knowledge) and organizational level (i.e. lack of training). 56 The professional bodies representing AHPs may consider relevant training to increase the prevalence and effectiveness of these conversations. The Henry project is a preventative childhood obesity programme aimed at training health professionals (e.g. health visitors, nursery nurses) and community workers (e.g. children's centre staff) to work more effectively with families of pre-school aged children. 57 The improvements in skills, knowledge and confidence in these populations 58 suggests that this may represent a viable model for the training of AHPs in the prevention of obesity.
Obesity Canada present guidance for paediatric obesity management which warrants consideration for AHPs in their routine 'contact points' with parents and/or young children. 59 This approach encourages more discussion of health-related behaviours, and less of a focus on numbers on the scale. The Canadian framework may provide an appropriate template for AHPs in discussions with parents of young children: • Askask permission to discuss weight • Assessobesity-related risk and potential 'root causes' of weight gain • Adviceon obesity risks, discuss treatment benefits and options  Table 3.
T A B L E 3 A summary of the practical and policy implications discussed within the report, as well as the research recommendations

Practical/policy considerations Research recommendations
All AHPs (not just dietitians) have a role to play in the prevention of obesity in young children. AHPs may contribute to the prevention of obesity in young children through weight management programmes/ services and/or via opportunistic 'contact points'.
Future research evaluating AHP-related interventions/programmes should be developed using the MRC and NIHR framework. 54 Authors of these studies may work with stakeholders to establish the most appropriate methodological approach to evaluate impactful research objectives. These principles are not limited to a research setting and may also apply to other wider obesity work undertaken by relevant stakeholders.
AHPs have the knowledge and skillset to train staff in settings/facilities in which contact with young children is common (e.g. childcare).
Trained staff in relevant settings may then lead healthy lifestyle interventions/programmes for these children. AHPs may also implement these programmes themselves Future research in this area may consider highlighting the role of AHPs in interventions/programmes via enhanced indexing and/or wording of published literature. This would allow for improved detection of AHPrelated literature and thus easier synthesis and evaluation of evidence in relation to the role of AHPs in the prevention of childhood obesity.
All AHP governing bodies may consider MECC training to ensure all AHPs are equipped to discuss obesity prevention. In addition, all AHPs should be provided with relevant signposting resources to improve the efficacy of these interactions. This training may also be facilitated by Universities, as well as employers when training students and staff respectively.
Future research may consider evaluating the impact of wider AHP roles in the prevention of childhood obesity.
AHP-related obesity prevention programmes are of benefit for the prevention of obesity in young children, but integration into a whole system (i.e. health visitors, childcare, education, local councils) approach to obesity is important to establish a collaborative and effective approach to the prevention of childhood obesity.
Further research may determine the effectiveness of using routine AHP 'contact points' for healthy lifestyle conversations and the subsequent prevention of childhood obesity.
A compassionate approach to weight management support should be provided in all settings and scenarios. This may be facilitated via use of the Obesity Canada 5 As guidelines for paediatric obesity management.
Further research may be conducted to evaluate how receptive parents of young children are to engage in opportunistic discussions about weight. It may be beneficial to conduct this research in coproduction with both patients and AHPs to determine the barriers and enablers to implementation of these conversations.

| LIMITATIONS
Although this report provides some valuable insight into the role of AHPs in the prevention of obesity in young children, some limitations must be acknowledged. The majority of included stud-