287 research outputs found

    Estimating the effects of preventive and weight-management interventions on the prevalence of childhood obesity in England: a modelling study

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    BACKGROUND: The effects of the systematic delivery of treatments for obesity are unknown. We aimed to estimate the potential effects on the prevalence of childhood obesity of systematically offering preventive and treatment interventions to eligible children in England, based on weight or health status. METHODS: For this modelling study, we developed a cross-sectional simulation model of the child and young adult population in England using data from multiple years of the Health Survey of England conducted between Jan 1, 2010, and Dec 31, 2019. Individuals were assessed for eligibility via age, BMI, and medical complications. Weight status was defined based on clinical criteria used by the UK National Institute of Health and Care Excellence. Published systematic reviews were used to estimate effect sizes for treatments, uptake, and completion for each weight-management tier. We used all available evidence, including evidence from studies that showed an unfavourable effect. We estimated the effects of two systematic approaches: a staged approach, in which children and young people were simultaneously given the most intensive treatment for which they were eligible, and a stepped approach, in which each management tier was applied sequentially, with additive effects. The primary outcomes were estimated prevalence of clinical obesity, defined as a BMI ≥98th centile on the UK90 growth chart, and difference in comparison with the estimated baseline prevalence. FINDINGS: 18 080 children and young people were included in the analytical sample. Baseline prevalence of clinical obesity was estimated to be 11·2% (95% CI 10·5 to 11·8) for children and young people aged 2-18 years. In modelling, we estimated absolute decreases in the prevalence of obesity of 0·9% (95% CI 0·1 to 1·8) for universal, preventive interventions; 0·2% (0·1 to 0·4) for interventions within a primary-care setting; 1·0% (0·1 to 2·1) for community and lifestyle interventions; 0·2% (0·0 to 0·4) for pharmaceutical interventions; and 0·4% (0·1 to 0·7) for surgical interventions. Staged care was estimated to result in an absolute decrease in the prevalence of obesity of 1·3% (-0·3 to 2·4) and stepped care was estimated to lead to an absolute decrease of 2·4% (0·1 to 4·8). INTERPRETATION: Although individual effect sizes for prevention and treatment interventions were small, when delivered at scale across England, these interventions have the potential to meaningfully contribute to reducing the prevalence of childhood obesity. FUNDING: UK National Institute for Health and Care Research

    Is it possible to model the impact of calorie-reduction interventions on childhood obesity at a population level and across the range of deprivation: Evidence from the Avon Longitudinal Study of Parents and Children (ALSPAC)

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    BACKGROUND: Simulated interventions using observational data have the potential to inform policy and public health interventions where randomised controlled trials are not feasible. National childhood obesity policy is one such area. Overweight and obesity are primarily caused by energy-rich and low-nutrient diets that contribute to a positive net energy imbalance. Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC), we investigated whether causal modelling techniques could be applied to simulate the potential impact of policy-relevant calorie-reduction interventions on population prevalence and inequalities in obesity in childhood. METHODS: Predicted probabilities of obesity at age 11 (UK90 cut offs) were estimated from logistic marginal structural models (MSM) accounting for observed calorie consumption at age 7 and confounding, overall and by maternal occupational social class. A series of population intervention scenarios were modelled to simulate daily calorie-reduction interventions that differed in effectiveness, targeting mechanism and programme uptake level. RESULTS: The estimated effect of maternal social class on obesity after accounting for confounding and observed calorie intake was provided by the controlled direct effect (CDE), in which, 18.3% of children were living with obesity at age 11 years,. A universal simulation to lower median intake to the estimated average requirement (EAR) (a 6.1% reduction in daily calories) with 75% uptake reduced overall obesity prevalence by 0.6%; there was little impact on inequalities. A targeted intervention to limit consumption to the EAR for children with above average intake reduced population obesity prevalence at 11 years by 1.5% but inequalities remained broadly unchanged. A targeted intervention for children of low-income families reduced prevalence by 0.7% and was found to slightly reduce inequalities. CONCLUSIONS: MSMs allow estimation of effects of simulated calorie-reduction interventions on childhood obesity prevalence and inequalities, although estimates are limited by the accuracy of reported calorie intake. Further work is needed to understand causal pathways and opportunities for intervention. Nevertheless, simulated intervention techniques have promise for informing national policy where experimental data are not available

    Childhood obesity and device-measured sedentary behavior : an instrumental variable analysis of 3,864 mother-offspring pairs

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    Objective Intergenerational data on mother-offspring pairs were utilized in an instrumental variable analysis to examine the longitudinal association between BMI and sedentary behavior. Methods The sample included 3,864 mother-offspring pairs from the 1970 British Cohort Study. Height and weight were recorded in mothers (age 31 [5.4] years) and offspring (age 10 years) and repeated in offspring during adulthood. Offspring provided objective data on sedentary behavior (7-day thigh-worn activPAL) in adulthood at age 46 to 47 years. Results Maternal BMI, the instrumental variable, was associated with offspring BMI at age 10 (change per kg/m(2), beta = 0.11; 95% CI: 0.09 to 0.12), satisfying a key assumption of instrumental variable analyses. Offspring (change per kg/m(2), beta = 0.010; 95% CI: -0.02 to 0.03 h/d) and maternal BMI (beta = 0.017; 95% CI: 0.001 to 0.03 h/d) was related to offspring sedentary time, suggestive of a causal impact of BMI on sedentary behavior (two-stage least squares analysis, beta = 0.18 [SE 0.08], P = 0.015). For moderate-vigorous physical activity, there were associations with offspring BMI (beta = -0.010; 95% CI: -0.017 to -0.004) and maternal BMI (beta = -0.007; 95% CI: -0.010 to -0.003), with evidence for causality (two-stage least squares analysis, beta = -0.060 [SE 0.02], P = 0.001). Conclusions There is strong evidence for a causal pathway linking childhood obesity to greater sedentary behavior

    Patterns of BMI development between 10-42 years of age and their determinants in the 1970 British Cohort Study

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    Background Mixture modelling is a useful approach to identify sub-groups in a population who share similar trajectories. We aimed to identify distinct BMI trajectories between 10-42 years and investigate how known early-life risk factors are related to trajectories. Methods Sample: 9,187 participants in the 1970 British Birth Cohort Study, with BMI observations between 10-42 years and data on birth-weight, parental BMI, socioeconomic status (SES), breastfeeding and puberty. Latent growth mixture modelling in Mplus was used to model age-related BMI trajectories and test associations of risk factors with trajectory membership. Results A three latent class model was most credible; 1) Normative: 92%: started normal weight but gradually increased BMI to become overweight in adulthood; 2) Childhood onset persistent obesity (COP): 4%: persistently high BMI from childhood; 3) Adolescent and young adulthood onset obesity (AYAO): 4%: normal weight in childhood but had a steep ascending trajectory. Higher maternal and paternal BMI and early puberty increased the probability of being in either the COP or the AYAO classes compared with the normative class. Conclusion Most individuals gradually increased BMI and became overweight in mid-adulthood. Only 8% demonstrated more severe BMI trajectories. Further research is needed to understand the underlying body composition changes and health risks in the COP and AYAO classes

    Additive influences of maternal and paternal body mass index on weight status trajectories from childhood to mid-adulthood in the 1970 British Cohort Study

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    This study aimed to (i)describe the weightstatus trajectories from childhood to mid-adulthood and (ii) investigate the influence ofmaternal and paternal body massindex (BMI) onoffspring’s trajectories in a nationally representative study inGreat Britain. Thesample comprised 4,174 (43% male) participantsfrom the 1970 British Cohort Study withcompleteBMI data at ages 10, 26, 30, 34, and 42years. Individuals’ weight status was categorised as overweight/obese or non-overweight/obese at eachage, and trajectories of weightstatus from 10 to42 years of age were assessed. Sex-stratified multinomial logistic regressionmodels were used to assess associations of maternal andpaternal BMI with trajectory group membership, adjusting for potential confounders (e.g.socioeconomicposition and puberty). Thirty per cent ofindividuals were never overweight/obese (reference trajectory),6%, 44%and 8%hadchildhood, early- and mid-adulthood onset of overweight/obesity (respectively), and 12% other trajectories. In fully adjusted models,highermaternal and paternal BMI significantlyincreased the risk of childhood (relativerisk ratio: 1.2-1.3) and early adulthood onset(1.2) of overweight/obesity in both sexes. Relative risk ratios were generall higher formaternal than paternal BMI in females but similar in males. Earlypuberty also increasedtherisk ofchildhood (1.8-9.2 and early-adulthoodonset (3.7-4.7)of overweight/obesity. Results highlight the importance of primary prevention, as mostindividuals remained overweight/obese after onset. Maternal and paternal BMI had additive effects on offspring weight status trajectories across 32 years of the life course,suggesting thatprevention/interventionprogrammes should focuson the whole famil

    Approaches to consent in public health research in secondary schools

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    OBJECTIVES: We assess different approaches to seeking consent in research in secondary schools. DESIGN: We review evidence on seeking active versus passive parent/carer consent on participant response rates and profiles. We explore the legal and regulatory requirements governing student and parent/carer consent in the UK. RESULTS: Evidence demonstrates that requiring parent/carer active consent reduces response rates and introduces selection biases, which impact the rigour of research and hence its usefulness for assessing young people's needs. There is no evidence on the impacts of seeking active versus passive student consent but this is likely to be marginal when researchers are directly in communication with students in schools. There is no legal requirement to seek active parent/carer consent for children's involvement in research on non-medicinal intervention or observational studies. Such research is instead covered by common law, which indicates that it is acceptable to seek students' own active consent when they are judged competent. General data protection regulation legislation does not change this. It is generally accepted that most secondary school students age 11+ are competent to provide their own consent for interventions though this should be assessed individually. CONCLUSION: Allowing parent/carer opt-out rights recognises their autonomy while giving primacy to student autonomy. In the case of intervention research, most interventions are delivered at the level of the school so consent can only practically be sought from head teachers. Where interventions are individually targeted, seeking student active consent for these should be considered where feasible

    Perceptions of health risk among parents of overweight children: a cross-sectional study within a cohort.

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    OBJECTIVE: To identify the socio-demographic and behavioural characteristics associated with perceptions of weight-related health risk among the parents of overweight children. METHODS: Baseline data from a cohort of parents of children aged 4-11 years in five areas in England in 2010-2011 were analysed; the sample was restricted to parents of overweight children (body mass index ≥ 91(st) centile of UK 1990 reference; n=579). Associations between respondent characteristics and parental perception of health risk associated with their child's weight were examined using logistic regression analyses. RESULTS: Most parents (79%) did not perceive their child's weight to be a health risk. Perception of a health risk was associated with recognition of the child's overweight status (OR 10.59, 95% CI 5.51 to 20.34), having an obese child (OR 4.21, 95% CI 2.28 to 7.77), and having an older child (OR 2.67, 95% CI 1.32 to 5.41). However, 41% of parents who considered their child to be overweight did not perceive a health risk. CONCLUSIONS: Parents that recognise their child's overweight status, and the parents of obese and older children, are more likely to perceive a risk. However, many parents that acknowledge their child is overweight do not perceive a related health risk

    The impact on dietary outcomes of licensed and brand equity characters in marketing unhealthy foods to children: A systematic review and meta-analysis

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    Licensed and brand equity characters are used to target children in the marketing of products high in fat, salt, and sugar (HFSS), but the impact of characters on dietary outcomes is unclear. The primary aim of this review was to quantify the impact of both licensed and brand equity characters on children's dietary outcomes given that existing regulations often differentiates between these character types. We systematically searched eight interdisciplinary databases and included studies from 2009 onwards until August 2021, including all countries and languages. Participants were children under 16 years, exposure was marketing for HFSS product with a character, and the outcomes were dietary consumption, preference, or purchasing behaviors of HFSS products. Data allowed for meta-analysis of taste preferences. A total of 16 articles (including 20 studies) met the inclusion criteria, of which five were included in the meta-analysis. Under experimental conditions, the use of characters on HFSS packaging compared with HFSS packaging with no character was found to result in significantly higher taste preference for HFSS products (standardized mean difference on a 5-point scale 0.273; p < 0.001). Narrative findings supported this, with studies reporting impact of both character types on product preferences including food liking and snack choice. There was limited evidence on the impact on purchase behaviors and consumption. These findings are supportive of policies that limit the exposure of HFSS food marketing using characters to children
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