8 The evidence

This section lists the evidence statements from 2 reviews provided by external contractors (see the section on what evidence is the guidance based on?) and links them to the relevant recommendations. (See the section on summary of the methods used to develop this guidance for the key to quality assessments.)

This section also lists 6 expert papers and 1 report commissioned by the Programme Development Group (PDG) and their links to the recommendations and sets out a brief summary of findings from the economic analysis.

The evidence statements are short summaries of evidence, in a review. Each statement has a short code indicating which document the evidence has come from. The letters in the code refer to the type of document the statement is from, and the numbers refer to the document number, and the number of the evidence statement in the document.

Evidence statement number 1.2.3 indicates that the linked statement is numbered 2.3 in review 1. Evidence statement number 2.1.1 indicates that the linked statement is numbered 1.1 in review 2. EP1 indicates that expert paper 1 is linked to a recommendation and CR1 indicates that the commissioned report is linked to a recommendation.

See the full reviews, expert reports, commissioned report and economic analysis. Where a recommendation is not directly taken from the evidence statements, but is inferred from the evidence, this is indicated by IDE (inference derived from the evidence).

Recommendation 1: evidence statements 1.1.10, 1.1.16, 1.1.33, 1.1.34, 1.1.35, 1.1.36, 1.2.3; EP1

Recommendation 2: evidence statements 2.1.40, 2.1.41, 2.1.42; EP1, EP2, EP4, CR1; IDE.

Recommendation 3: evidence statements 1.1.10, 1.1.16, 1.1.33, 1.1.34, 1.2.2, 1.2.3, 1.4.1, 1.4.2, 2.1.13, 2.1.14, 2.1.15, 2.1.16, 2.1.17, 2.1.23, 2.1.25, 2.1.26, 2.1.27, 2.1.32, 2.1.33, 2.1.34; EP3, EP5, EP6

Recommendation 4: evidence statements 1.1.14, 1.2.3, 1.4.1, 1.4.2, 2.1.5, 2.1.8, 2.1.10, 2.1.13, 2.1.15, 2.1.25, 2.1.26, 2.1.27, 2.1.31, 2.1.33, 2.2.4, 2.2.5; EP3, EP6; IDE

Recommendation 5: evidence statements 1.1.10, 1.1.16, 1.2.3, 1.4.3, 2.1.12, 2.1.13, 2.1.15, 2.1.22, 2.1.23, 2.1.24, 2.1.28, 2.1.29, 2.1.30, 2.1.38, 2.1.39, 2.2.4, 2.2.5; EP5, CR1, IDE

Recommendation 6: evidence statements 2.1.11, 2.1.18, 2.1.19, 2.1.20, 2.1.32; EP1, CR1; IDE

Recommendation 7: evidence statements 2.1.18, 2.1.19; 2.1.20; EP1; IDE

Recommendation 8: evidence statements 1.2.7, 1.4.3, 2.1.4, 2.1.7, 2.1.8, 2.1.9, 2.1.10, 2.1.11, 2.1.14, 2.1.16, 2.1.19; EP1, EP3, CR1; IDE

Recommendation 9: evidence statements 1.1.33, 1.1.34, 1.4.1, 1.4.2, 1.4.3, 2.1.1, 2.1.2, 2.1.3, 2.1.4, 2.1.34; EP3, CR1; IDE

Recommendation 10: evidence statements 1.1.33, 1.1.34, 1.4.1, 1.4.2, 2.1.34, 2.1.35, 2.1.36, 2.1.37; CR1; IDE

Recommendation 11: evidence statements 2.1.8, 2.1.10, 2.1.11, 2.1.38, 2.1.39, 2.1.41, 2.1.42; EP1, EP5, CR1; IDE

Recommendation 12: evidence statements 2.1.38, 2.1.39, 2.1.41, 2.1.42; EP1, EP3, EP5, EP6, CR1; IDE

Recommendation13: evidence statements 1.2.4, 2.1.8, 2.1.10, 2.1.19; EP1; IDE

Recommendation 14: EP1; IDE

Recommendation 15: evidence statements 1.4.1, 1.4.2; EP1, EP4, EP5 CR1; IDE

Evidence statements

Please note that the wording of some evidence statements has been altered slightly from those in the evidence reviews to make them more consistent with each other and NICE's standard house style.

Evidence statement 1.1.10 Child and parent/carer interventions – anthropometric outcomes

There is strong evidence from 8 studies (3 [++] randomised controlled trials [RCTs], 2 [+] RCTs, 2 [−] quasi-RCTs and 1 [−] uncontrolled before-after [UBA] study) that child/adolescent and parent interventions result in significant decreases in body mass index (BMI) z score based on baseline to follow-up within group measures. This evidence is directly applicable because the studies were carried out in community settings in the USA, Australia and the UK.

Evidence statement 1.1.14 Child and parent/carer interventions – wellbeing outcomes

There is strong evidence from 2 (++) RCTs that group-based behaviour-change interventions directed at children/adolescents and parents have significant beneficial effects on some psychosocial outcomes. One (++) RCT showed a group difference at 18 months for body satisfaction (p=0.026) and appearance (p=0.019) although no group differences on other psychosocial outcomes. A second (++) RCT showed group difference at 12 months for scholastic competence (p=0.049), but not other psychosocial outcomes. Two hundred and eight overweight adolescent females aged 12 to 17 received a 5‑month intervention delivered by nutritionists, health educators and clinical psychologists. Dietitians delivered a 2‑year intervention to 151 overweight and obese adolescents (52% female). This evidence is directly applicable because studies were conducted in community settings respectively in the USA, Australia and the UK.

Evidence statement 1.1.16 Family interventions – anthropometric outcomes

There is strong evidence from 18 papers on 17 studies (5 [++] RCTs, 4 [+] RCTs, 1 [+] quasi-RCT, 1 [−] quasi-RCT and 6 [−] UBAs) that, for overweight and obese children and adolescents, whole family interventions whether directed at individual families or group-based result in significant decreases in BMI z score based on baseline to follow-up for within group measures. All but 1 UBA (which focused on diet and physical activity) and 1 quasi-RCT (behaviour change only) assess the effectiveness of multi-component interventions focusing on behaviour change. This evidence is applicable because all studies are community-based, 11 were conducted in the UK, 3 in the USA, 2 in Australia and 1 in Italy.

Evidence statement 1.1.33 Meta-analyses: child and parent or whole family interventions – anthropometric outcomes

A meta-analysis of 8 studies (4 [++] RCTs, 3 [+] RCTs and 1 [−] quasi-RCT) estimated the overall effectiveness of interventions directed at children and parents/carers or whole family versus no or minimal control outcomes immediately post intervention as a significant reduction in BMI standardised mean difference (SMD) of −0.22 (−0.33 to −0.10). This evidence is directly applicable because the studies were conducted in the UK and other similar community-based settings.

Evidence statement 1.1.34 Meta-analyses: child and parent or whole family interventions – anthropometric outcomes

A meta-analysis of 11 studies (7 [++] RCTs; 3 [+] RCTs and 1 [−] quasi-RCT) estimated the overall effectiveness of interventions directed at children and parents/carers or whole family versus no or minimal control outcomes at longer-term follow up (6 months or more) as a non-significant reduction in BMI SMD of −0.01 (−0.11 to 0.08). This evidence is directly applicable because the studies were conducted in the UK or other similar community-based settings.

Evidence statement 1.1.35 Cost effectiveness

Evidence from 7 short-term health economic analyses suggests that lifestyle weight management programmes will result in an increased cost to the NHS in terms of BMI z score gains when compared with routine care in the short term. However, overall small (and in some cases, non-significant) improvements in BMI z scores can be achieved. All studies were applicable in terms of setting and participants, but data from short-term studies are limited in applicability to life-time cost estimates and assessed as partially applicable. Some studies provided cost data only and there was no assessment of their applicability or study limitations.

Evidence statement 1.1.36 cost effectiveness

Three extrapolation models of programmes suggest interventions that lead to even small reductions in BMI can be cost effective in the long term at conventional cost-effectiveness thresholds, provided the short-term effects on BMI, observed in trials, are sustained into adulthood. The evidence from these studies is directly applicable but there are potentially serious limitations to the studies.

Evidence statement 1.2.2 Parenting skills.

There is strong evidence from 2 RCTs (both [++]) that interventions involving group-based general parenting skills training for parents of overweight and obese children aged 6 to 9 years and 5 to 9 years are effective in improving BMI z scores. Adding intensive lifestyle education to the parenting skills training does not appear to result in significantly greater improvements in BMI z scores, food intake or physical activity measures or parenting outcomes. Both interventions were delivered over 6 months by dietitians. This evidence is directly applicable because the studies were conducted in community settings in Australia.

Evidence statement 1.2.3 Involvement of family

There is strong evidence, post intervention, to suggest that targeting both parents and children (8 studies: 3 [++] RCTs, 2 [+] RCTs, 2 [−] quasi-RCTs and 1 [−] UBA) or whole families (18 papers from 17 studies: 5 [++] RCTs, 4 [+] RCTs, 1 [+] quasi-RCT, 1 [−] quasi-RCT and 6 [−] UBAs) is effective in reducing within group BMI z scores. For those studies with follow up of 6 months or more there were no clear differences. Evidence from child-only interventions (1 [++] RCT, 1 [+] RCT and 1 [−] CBA) and parent-only interventions (2 [++] RCTs, 2 [+] RCTs and 1 [−] cluster RCT) is limited and inconsistent.

Evidence statement 1.2.4 Referral method

There is strong evidence from a meta-analysis of 12 studies, of which 2 studies examined specialist referral, to suggest that interventions that involve specialist medical referral to a programme compared with self, GP, school or a mixture of referral methods show greater improvements in BMI z scores at end of intervention (SMD of −0.41; 95% confidence interval [CI] of −0.64 to −0.17). The studies in the meta-analysis were conducted in applicable community settings.

Evidence statement 1.2.7 Intensity of intervention

There is moderate evidence from 1 (−) RCT and 1 (++) RCT that children who attend 75% or more of the high intensity programme sessions offered, showed greater improvements in weight outcomes than those attending fewer sessions. One further ongoing (++) RCT found that following up CBT therapy with telephone or text coaching was not more beneficial to BMI z scores, diet, physical activity and psychosocial outcomes than CBT alone. The studies in both meta-analysis were conducted in community settings in the USA and Australia.

Evidence statement 1.4.1 Most effective ways of sustaining long-term effects

There is inconsistent evidence as to whether the effects of weight management programmes are sustained long term. There is strong evidence from meta-analyses of 18 programmes (10 [++] RCTs [11 papers], 5 [+] RCTs, 3 quasi-RCTs – 1 [+], 2 [−]) with BMI z outcomes, indicating improvements decrease the longer the length of follow-up. The evidence is directly applicable because all studies were conducted in community settings in the UK or other similar countries and are directly applicable.

Evidence statement 1.4.2 Most effective ways of sustaining long-term effects

Considering BMI plus other outcomes, there is inconsistent evidence from 5 (++) RCTs, 1 (+) RCT, 1 (+) quasi-RCT and 1 [−] UBA as to whether the effects of weight management programmes are sustained long term. It is not possible to determine which intervention components resulted in sustained outcomes. The evidence is directly applicable because all studies were conducted in community settings in the UK or other similar countries.

Evidence statement 1.4.3 Duration of interventions

A meta-analysis of 8 studies (4 [++] RCTs, 3 [+] RCTs, 1 [−] RCT) indicated that duration of intervention is associated with improved between-group BMI z outcomes at the end of the intervention for programmes of 8 to 24 months. There were no significant between group differences in BMI z scores associated with studies of a shorter duration. Between-group differences diminished over time and were not significant at 6 months. The evidence is directly applicable as the studies were conducted in the UK and the USA.

Evidence statement 2.1.1 Facilitator: weight management goals

There is evidence from 5 qualitative studies (4 [+] and 1 [−]) that the desire to lose weight or prevent further weight gain was a motivator for programme users to join and continue attendance at lifestyle weight management programmes. In 8 studies, perceived improvements in children's and/or young people's weight management outcomes were described by programme providers (1 [+] qualitative study) and programme users (1 [++] qualitative, 4 [+] qualitative, and 2 process evaluations). This evidence is directly applicable because the studies were conducted in community-based settings in the UK or other similar countries (USA).

Evidence statement 2.1.2 Facilitator: health improvement goals

Health improvement or prevention of future health problems were described as incentives to joining weight management programmes by children and families in 6 qualitative studies (2 [++], 3 [+] and 1 [−]). Providers in 1 (+) qualitative study and programme users in 4 studies (3 process evaluations, 1 [+] qualitative study) perceived health improvements as a consequence of attending weight management programmes. This evidence is directly applicable because studies were conducted in the UK in community-based settings.

Evidence statement 2.1.3 Facilitator: healthier lifestyle behaviour

Weight management programmes were perceived to improve children's lifestyle behaviours, such as healthier diet and increased physical activity, by programme providers in 2 process evaluations, and also by programme users in 5 studies (1 [++] qualitative, 2 [+] qualitative, 1 [−] qualitative and 1 process evaluation). The evidence is directly applicable because the studies were conducted in the UK in community-based settings.

Evidence statement 2.1.4 Barrier: lack of programme impact on weight management

Concerns that programmes were not helping children achieve weight management goals were expressed by providers in 1 (−) qualitative study and by parents in 1 (+) qualitative study. In both studies the weight outcome was described in terms of weight loss, without reference to the wider aims of most weight management programmes to slow further weight gain so that BMI z scores improve as children grow. Also, children in 1 (++) qualitative study stated that weight gain prompted feelings of embarrassment and shame, and led to non-attendance at booked appointments. There were different views between studies and between the participants of the same studies as to whether weight was the most important outcome. Two (+) qualitative studies suggested psychological wellbeing was of equal or greater importance to parents, whereas weight outcomes appeared more important to some children in 2 (+) qualitative studies and to parents in 1 (−) qualitative study. This evidence is directly applicable because the studies were conducted in community settings in the UK and Sweden.

Evidence statement 2.1.5 Facilitator: psychological wellbeing and social outcomes

Improved psychological wellbeing such as confidence and self-esteem, or improved social outcomes such as reduced bullying and making friends, were strong motivators for programme participation among children and their families in 10 studies (2 [++] qualitative, 6 [+] qualitative, and 2 [−] qualitative). Programmes were perceived to be successful in improving these outcomes in 12 studies (2 [++] qualitative, 4 [+] qualitative, 2 [−] qualitative, 4 process evaluations). Two studies suggested that improvements in these outcomes were sufficient to maintain engagement with programmes despite lack of weight management. This evidence is directly applicable because the studies were conducted in community settings in the UK or similar countries (the USA, Sweden, Australia).

Evidence statement 2.1.7 Facilitator: children's motivation to manage weight

High levels of children's motivation to manage weight was reported in 6 qualitative studies (3 [++], 2 [+] and 1 [−]) and helped promote participation in weight management programmes. This evidence is directly applicable because the studies were conducted in community settings in the UK or similar countries (the USA, Sweden).

Evidence statement 2.1.8 Facilitator: awareness and acceptance of children being overweight or obese

Children, their families and providers emphasised that awareness and acceptance of children being overweight or obese was a facilitator to programme adherence. This was evidenced in 6 qualitative studies (3 [++], 2 [+], 1 [−]). This evidence is directly applicable because the studies were conducted in community settings in the UK or similar countries (United States, Sweden).

Evidence statement 2.1.9 Barrier: lack of children's motivation

Programme users and providers shared views that children's lack of motivation was a barrier to uptake of lifestyle weight management programmes. This was described in 1 (+) qualitative study and 1 process evaluation. Lack of motivation was also described by programme users and providers as a barrier to programme adherence in 7 studies (1 [++] qualitative, 3 [+] qualitative, 1 [−] cross-sectional, 1 [−] qualitative, and 1 process evaluation). This evidence is directly applicable because studies were conducted in community settings in the UK or similar countries (Australia, Sweden, Canada, the USA).

Evidence statement 2.1.10 Barrier: lack of awareness and acceptance of children being overweight or obese

Family and provider perspectives in 5 studies (1 [++] qualitative, 2 [+] qualitative, 1 [+] cross-sectional and 1 [−] qualitative study) indicated that some families do not acknowledge or recognise that their child is overweight or obese, which hindered programme uptake and adherence. This evidence is directly applicable because studies were conducted in community settings in the UK or similar countries (Canada, Belgium).

Evidence statement 2.1.11 Barrier: children's and their parents' apprehension

A strong theme identified in 5 qualitative studies (1 [++], 3 [+] and 1 [−]) was the anxiety and apprehension described by children and parents about joining weight management programmes. Concerns manifested as general fears of the unknown (for example, anxieties of meeting new people, struggling to make friends or worries of being the largest on the programme). In addition, there were reports in 3 qualitative studies (1 [+], 2 [−]) and 1 process evaluation of programme users having negative perceptions of the programme characteristics and eligibility criteria before starting the intervention. This evidence is directly applicable because studies were conducted in community settings in the UK or similar countries (USA).

Evidence statement 2.1.12 Barrier: individual and family demands

Parents and children described a range of individual and family demands, such as busy lifestyles, homework, work or family commitments. These were indicated as obstacles to programme uptake or adherence in 10 studies (2 [++] qualitative, 3 [+] qualitative, 1 [+] cross-sectional, 1 [−] cross-sectional, 1 [−] qualitative and 2 process evaluations). This evidence is directly applicable because studies were conducted in community settings in the UK or similar countries (Australia, Canada, Iceland, Belgium.).

Evidence statement 2.1.13 Facilitator: parental support

Both providers and children were reported as believing parental support to be an important facilitator of successful lifestyle weight management interventions. High levels of parental support and their role in children's weight management was described in 5 qualitative studies (1 [++], 3 [+], 1 [−]). A (+) cross-sectional study identified parents' motivation for treatment as a statistically significant predictor of programme completion. This evidence is directly applicable because studies were conducted in community settings in the UK or similar countries (the USA, Belgium).

Evidence statement 2.1.14 Facilitator: parental motivation

Parental motivation was perceived to be a critical factor in children's successful engagement with weight management programmes, as evidenced in 7 studies: 3 qualitative (2 [+], 1 [−]); 3 cross-sectional surveys (2 [+], 1 [−]) and 1 process evaluation. Perceptions of high levels of parental motivation were reported in 3 studies, primarily from parents whereas providers acknowledged high parent motivation in only 1 study. Two studies found a statistically significant association between motivated parents and either programme uptake or completion. This evidence is directly applicable because studies were conducted in community settings in the UK or similar countries (Belgium, Australia, the USA).

Evidence statement 2.1.15 Barrier: lack of parental support

Providers reported a lack of parental support acting as a barrier to children's weight management in 4 qualitative studies (1 [++], 2 [+], 1 [−]). Three of these studies described provider perceptions that parents did not realise their role as agents of change and they looked to the programme to solve children's weight management difficulties. This evidence is directly applicable because studies were conducted in the UK in a community setting.

Evidence statement 2.1.16 Barrier: lack of parental motivation

Programme providers described how low parental motivation hindered children's weight management in 1 (+) qualitative study, 1 (−) qualitative study and 1 process evaluation. In addition, a small proportion of parents (4.7%) cited lack of family readiness to change as a reason for dropping out of a lifestyle weight management programme in 1 (−) cross-sectional study. This evidence is directly applicable because studies were conducted in community settings in the UK or similar countries (Belgium, USA).

Evidence statement 2.1.17 Barrier: lack of support from other family members

Children and parents described situations in which other family members (either partners or members outside of the nucleus family such as grandparents) did not support, and even sabotaged, children's weight management attempts. This was described in 8 qualitative studies (2 [++], 4 [+], 1 [−]). This evidence is directly applicable because studies were conducted in community settings in the UK or similar countries (USA).

Evidence statement 2.1.18 Barrier: lack of awareness

Both providers and programme users identified a lack of awareness of local weight management programmes. Providers considered poor programme publicity to be the reason why potential users were unaware of the programme in 1 process evaluation. Programme users also reflected on the lack of programme awareness among children and families in 4 qualitative studies (1 [+], 3 [−]). Providers and users also referred to health professionals' lack of programme awareness in 1 process evaluation and 1 qualitative study. This evidence is directly applicable because all studies were conducted in UK community settings.

Evidence statement 2.1.19 Role of health professionals

Both programme users and providers felt that health professionals such as GPs, nurses and health visitors should raise awareness or refer children to lifestyle weight management programmes. However, varying opinions were offered on whether this was being sufficiently implemented. Examples of awareness-raising by other professionals were reported by providers or programme users in 2 (+) qualitative studies, 1 (−) qualitative study and 1 process evaluation. However, providers in 3 studies (1 [+] qualitative, 2 process evaluations) and programme users in 1 (+) qualitative study, described circumstances in which children were not referred, or inappropriate referrals were made. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (USA).

Evidence statement 2.1.20 Facilitator: recruitment suggestions

Programme users and providers offered varied suggestions for future programme recruitment strategies in 8 studies (2 [++] qualitative, 4 process evaluations, 2 [−] qualitative). Increasing referral routes, recruiting through schools and family support workers, was suggested by both programme providers and users; advertising in local media was suggested by providers and users. Providers also mentioned ensuring programme aims and characteristics were sufficiently described and offering rolling programmes that allow families to join on an ongoing basis. Users felt that emphasising the healthy living and fun aspects of programmes rather than weight management would promote uptake. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (USA).

Evidence statement 2.1.22 Facilitator: venue

Programme users valued the comfortable and welcoming environment of their programme venues in 2 (+) qualitative studies, which were either located in a clinic or at schools. Community settings and schools were suggested by providers and programme users as suitable venues in 1 (++) qualitative study and 2 process evaluations. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Canada).

Evidence statement 2.1.23 Facilitator: family involvement

Providers, children and families valued a delivery approach that incorporated family involvement in lifestyle weight management programmes, perceiving it to facilitate behaviour change. Users expressed these views in 11 studies (2 [++] qualitative, 4 [+] qualitative, and 5 process evaluations) and providers in 3 studies (1 [++] qualitative study, 1 [−] qualitative study and 1 process evaluation). Regarding specific parenting education sessions, users in receipt of these interventions liked the emphasis on positive parenting and separate children and parent sessions addressing the same topic as each other. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Australia, Canada, USA).

Evidence statement 2.1.24 Facilitator: group intervention sessions with peers

There was evidence from 13 studies (2 [++] qualitative, 3 [+] qualitative, 3 [−] qualitative, 5 process evaluations) that group-based sessions and interaction with peers were highly valued by children and parents. Interventions incorporating group sessions or peer interactions were perceived to be opportunities to share experiences, and give and receive support from people facing similar problems. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Sweden).

Evidence statement 2.1.25 Facilitator: goal setting

Programme users and providers shared the view that the use of goal setting (which may or may not also involve rewards) was a beneficial feature of interventions, and emphasised the importance of frequent but small and realistic goals. This was evidenced in 11 studies (2 [++] qualitative, 6 [+] qualitative, and 3 process evaluations). This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Canada, USA).

Evidence statement 2.1.26 Facilitator: user-tailored interventions

Programme users and providers highly valued the interventions that were tailored to the user in 9 studies (6 qualitative: 2 [++], 2 [+], 2 [−]; 1 [+] cross-sectional survey and 2 process evaluations).

Interventions were viewed positively if they were tailored to different population groups of children (for example, age, gender, ethnicity) by parents, providers and children. There was a strong emphasis on the value of interventions addressing the individual personal needs of programme users. Programme users commented on the importance of identifying and adjusting interventions to the needs, goals, motives or existing knowledge of individual participants. Providers in 1 study recommended tailoring programmes to children's age, ethnicity, degree of obesity and their readiness for change. Authors in 1 study also commented on the benefits of collaborating with families to create individual goals and strategies. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Canada, USA and Sweden).

Evidence statement 2.1.27 Facilitator: monitoring and feedback

There was evidence from 10 studies that regular monitoring and feedback of weight management progress was highly valued by programme users and providers (2 [++] qualitative, 4 [+] qualitative, 2 [−] qualitative studies, and 2 process evaluations). This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Sweden).

Evidence statement 2.1.28 Facilitators: scheduling suggestions

Suggestions for improving programme scheduling were offered by programme users and providers in 9 studies (1 [++] qualitative, 2 [+] qualitative, 1 [+] qualitative, 1 [+] cross-sectional survey and 4 process evaluations). More flexible appointment times, such as in the evening or weekends were suggested by programme users and providers. Programme users also wanted increased frequency of appointments to maintain their motivation. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Australia, USA).

Evidence statement 2.1.29 Barrier: inconvenient intervention scheduling

Scheduling of interventions (for example, timing, length of individual sessions) were important influences on programme users but no clear consensus was described on what the scheduling should be.

Potential users cited inconvenient timing of programmes as a reason for not joining programmes in 1 (−) qualitative study and 2 process evaluations. Programme attendees also reported difficult scheduling as a barrier to continued participation in 10 studies (2 [++] qualitative studies, 2 [+] qualitative studies, 1 [+] cross-sectional survey, 3 process evaluations, 1 [−] cross-sectional and 1 [−] qualitative study). Programme users in 1 survey disagreed on how the frequency of appointments resulted in their attendance or drop-out. 11.6% dropped out of programmes because appointments were not frequent enough, whereas 7% stated they were too frequent. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Australia, Canada, USA).

Evidence statement 2.1.30 Barrier: venue location

Negative comments regarding programme venues were expressed in 6 studies (3 [+] qualitative, 1 [−] qualitative, 1 [−] cross-sectional survey and 1 process evaluation). Challenges relating to locations being too far away, difficult to reach, or hindered by traffic problems at peak times were described by both providers and users. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Canada and USA).

Evidence statement 2.1.31 Barrier: challenges in goal setting

Challenges of setting goals within programmes were highlighted by users and providers in 3 studies (1 [++] qualitative, and 2 process evaluations). Programme users spoke negatively about too many goals being set, long-term goals not being revisited or monitored or goals not being matched to those valued by the child. Providers described difficulties in designing goals for users. This evidence is directly applicable because all studies conducted in community settings in the UK or similar countries (Sweden, Australia).

Evidence statement 2.1.32 Facilitator: practical intervention elements

A recurring theme within studies was that programme users particularly liked the practical elements of their intervention sessions, as evidenced in 11 studies: 7 qualitative (1 [++], 4 [+], 2 [−]) and 4 process evaluations.

Regarding dietary components, children and/or parents enjoyed cookery lessons in particular or wanted the programme to incorporate more of these. Specific directive information was also valued, including the provision of recipes, eating plans or messages that 'told them what to do'. Education on food in supermarkets was also valued, with 1 study suggesting that education on labels should be followed up with trips to the supermarket.

Regarding physical activity education, children consistently commented on enjoying games and physical exercise sessions, and views indicated they would like more activities within the intervention. Some parents also wanted more exercise sessions, although some parents expressed negative views of physical activity sessions. Variety in the available activities was also valued. This evidence is directly applicable because all studies were conducted in community settings in the UK.

Evidence statement 2.1.33 Facilitator: behavioural change components

Parents and children had positive views of the behavioural change elements in the programmes they received, evidenced in 7 studies: 5 qualitative (1 [++], 2 [+], 2 [−]) and 2 process evaluations. Positive comments were made regarding: understanding the 'how and why' of their eating behaviour, learning about their feelings and being able to talk about how they feel, or learning about stress and how to cope with it. One study reported that users believed lifestyle weight management programmes should include physical activity, nutrition and psychological components. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Canada, the USA).

Evidence statement 2.1.34 Barrier: relevance of intervention to home life

Seven studies described children's and/or their families' concerns with the relevance and ease of managing their weight outside in their home life or after leaving their programme (4 [++], 1 [+], 1 [−] qualitative and 1 [+] cross-sectional study). This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Belgium).

Evidence statement 2.1.35 Facilitator: post-intervention support and follow-up

Seven studies (1 [++] qualitative, 2 [+] qualitative, 2 [−] qualitative, 2 process evaluations) identified that the continuation of professional support following completion of the programme was important to users. Families wanted support to continue and thought it would be helpful for ensuring that weight management goals were continued.

Very little detail was provided regarding the forms this support should take. Parents in 1 study suggested follow-up letters, meetings or continuation sessions. Parents in another study proposed a long-term financial subsidy to encourage children and young people to maintain participation in formal activities.

This evidence is directly applicable because all studies were conducted in UK community settings.

Evidence statement 2.1.36 Facilitator: personal strategies to sustain weight management behaviour

Parents in 3 studies (2 [+] qualitative, 1 process evaluation) described a range of strategies they employed to facilitate continuation of their children's weight management behaviour. These included staying consistent, setting planned routines, enjoying their new healthy lifestyle, and seeking additional support. This evidence is directly applicable because all studies were conducted in the UK community settings.

Evidence statement 2.1.37 Barrier: attendance at follow-up sessions

Despite strong support for professional follow-up after completion of weight management programmes, children and parent views in 3 studies suggested that the content and timing of potential support may affect the uptake of sessions if they did not appeal to programme users or conflicted with their competing interests. This was indicated in 3 qualitative studies: (1 [++], 1 [+] and 1 [−]). This evidence is directly applicable because studies were conducted in the UK community settings or similar countries (Canada).

Evidence statement 2.1.38 Facilitator: building good child/family-provider relationships

There was evidence from 15 studies (3 [++] qualitative, 6 [+] qualitative, 4 process evaluations, and 2 [−] qualitative) of children's and parents' perspectives, that provider characteristics were key factors for continued participation in weight management programmes and behaviour change attempts. Valued characteristics included the encouraging, non-judgemental tone of providers, and continuity of staff. Parents also appreciated the role providers had in acting as voices of authority that parents could rely on to educate children. Provider perspectives in 2 of these studies also suggested that staff were aware of the importance of establishing good relationships with programme users and their families. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Canada, Sweden, the USA Australia).

Evidence statement 2.1.39 Barrier: negative opinions of providers' characteristics

Six studies (2 [++] qualitative, 2 [+] qualitative, 1 process evaluation, 1 [−] qualitative) described how negative opinions of provider dynamics influenced user engagement. Children and parents provided examples of poor user-provider relationships and suggested they hindered engagement with programmes or weight management behaviour Providers also recognised the negative effect bad relationships with users and staff discontinuity could have on programme adherence. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Canada, Sweden).

Evidence statement 2.1.40 Facilitator: collaborative multi-disciplinary teams

Three studies (1 [+] qualitative study, 1 process evaluation and 1 [+] cross-sectional survey) indicated that providers highly valued working within effective collaborative multidisciplinary teams. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Australia).

Evidence statement 2.1.41 Facilitator: provider highly valued opportunities for training

Three studies (1 [+] qualitative, 1 process evaluation and 1 [+] cross-sectional survey) reported that providers were keen to receive relevant training that would help them gain necessary skills to effectively deliver interventions. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Australia).

Evidence statement 2.1.42 Barrier: provider gaps in knowledge

Three studies (1 [+] qualitative study, 1 [+] cross-sectional study and 1 process evaluation) referred to providers' perceptions of their skills and knowledge. Three studies indicated some providers felt unqualified to deliver interventions, specifically interventions that were broad in their nature, or were delivered to a varying user group who sometimes had complex psychosocial needs. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Australia).

Evidence statement 2.2.4 Pre-adolescent children (6 to 13 years)

A wide range of themes was described in 16 studies of school-age children: 7 qualitative (3 [++], 3 [+], 1 [−]), 1 (+) correlation, 2 cross-sectional, 6 process evaluations. However, none of the studies were designed to explore differences in barriers and facilitators compared with other age groups.

Commonly shared facilitators across studies were the importance of non-weight outcomes such as psychological wellbeing, social outcomes such as making friends and reduced bullying; interventions with a whole-family approach; positive provider characteristics; group-based sessions with peers; regular monitoring and feedback; and post-intervention support. Commonly shared barriers across studies were poor relationships of providers with children and/or their parents. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Canada, Australia, the USA, Iceland, Belgium).

Evidence statement 2.2.5 Adolescents

A wide range of themes was described in 10 studies of adolescents (2 [++] qualitative, 3 [+] qualitative, 1 [+] cross-sectional survey, 4 process evaluations). However, none of the studies were designed to explore differences in barriers and facilitators for adolescents when compared with other age groups. Facilitators shared across 3 or more studies were the importance of psychological wellbeing as an outcome and positive provider characteristics. Commonly shared barriers across studies were: perceived lack of parental support and concern regarding unintended consequences of weight management programmes. This evidence is directly applicable because all studies were conducted in community settings in the UK or similar countries (Australia the USA and Sweden).

Expert papers and commissioned report

  • Expert papers 1 to 6.

  • Commissioned report.

For details, see the section on what evidence is the guidance based on?

Economic modelling

The economic model considered the BMI trajectory of children in 3 different age groups (2 to 5 years, 7 to 11 years and 12 to 17 years). It considered boys and girls separately. It also considered 3 starting weights for each age group and both sexes. The starting weights considered were: the borderline between healthy weight and overweight, between overweight and obese, and between obese and what the model called morbidly obese.

The model examined what happened to each cohort if there were no intervention. It estimated the average (mean) weight and quality of life for the cohort on an annual basis and its expected life expectancy. It also estimated the costs of any health problems they would face during their lifetime. The model was then set up to answer 2 questions:

  • What would happen to the quality of life and the life expectancy of each of these groups of children or young adults if an intervention from the evidence review were applied?

  • How would the future costs of treating diseases change as the result of the intervention?

The difference between the subsequent lifelong pathways of these 2 hypothetical situations (that is, 'with an intervention' and 'without an intervention') was expressed in terms of quality-adjusted life years (QALYs) gained from the intervention. It was also expressed in terms of the cost of the intervention less the future costs saved. An intervention is generally considered to be cost effective if the cost per QALY gained is less than about £20,000 to £30,000.

The model estimated that an intervention costing £100 per person would be cost effective if a child or young person could be moved to a lower weight trajectory (as little as 0.5% lower) than it would have been without the intervention. However, this would be the case only if the 0.5% weight difference were to be maintained throughout life. If, on average, they regained the weight within 10 years or less it is estimated that the intervention would no longer be cost effective.

  • National Institute for Health and Care Excellence (NICE)