104 research outputs found

    An improved algorithm to harmonize child overweight and obesity prevalence rates

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    BACKGROUND: Prevalence rates of child overweight and obesity for a group of children vary depending on the BMI reference and cut-off used. Previously we developed an algorithm to convert prevalence rates based on one reference to those based on another. OBJECTIVE: To improve the algorithm by combining information on overweight and obesity prevalence. METHODS: The original algorithm assumed that prevalence according to two different cut-offs A and B differed by a constant amount dz dz dz on the z-score scale. However the results showed that the z-score difference tended to be greater in the upper tail of the distribution and was better represented by b × dz b×dz b\times dz , where b b b was a constant that varied by group. The improved algorithm uses paired prevalence rates of overweight and obesity to estimate b b b for each group. Prevalence based on cut-off A is then transformed to a z-score, adjusted up or down according to b × dz b×dz b\times dz and back-transformed, and this predicts prevalence based on cut-off B. The algorithm's performance was tested on 228 groups of children aged 6-17 years from 20 countries. RESULTS: The revised algorithm performed much better than the original. The standard deviation (SD) of residuals, the difference between observed and predicted prevalence, was 0.8% (n = 2320 comparisons), while the SD of the difference between pairs of the original prevalence rates was 4.3%, meaning that the algorithm explained 96.7% of the baseline variance (88.2% with original algorithm). CONCLUSIONS: The improved algorithm appears to be effective at harmonizing prevalence rates of child overweight and obesity based on different references

    Exploring an algorithm to harmonize International Obesity Task Force and World Health Organization child overweight and obesity prevalence rates

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    BACKGROUND: The International Obesity Task Force (IOTF) and World Health Organization (WHO) body mass index (BMI) cut-offs are widely used to assess child overweight, obesity and thinness prevalence, but the two references applied to the same children lead to different prevalence rates. OBJECTIVES: To develop an algorithm to harmonize prevalence rates based on the IOTF and WHO cut-offs, to make them comparable. METHODS: The cut-offs are defined as age-sex-specific BMI z-scores, for example, WHO +1 SD for overweight. To convert an age-sex-specific prevalence rate based on reference cut-off A to the corresponding prevalence based on reference cut-off B, first back-transform the z-score cut-offs z A and z B to age-sex-specific BMI cut-offs, then transform the BMIs to z-scores z B , A and z A , B using the opposite reference. These z-scores together define the distance between the two cut-offs as the z-score difference dz A , B = 1 2 z B - z A + z A , B - z B , A . Prevalence in the target group based on cut-off A is then transformed to a z-score, adjusted up or down according to dz A , B and back-transformed, and this predicts prevalence based on cut-off B. The algorithm's performance was tested on 74 groups of children from 14 European countries. RESULTS: The algorithm performed well. The standard deviation (SD) of the difference between pairs of prevalence rates was 6.6% (n = 604), while the residual SD, the difference between observed and predicted prevalence, was 2.3%, meaning that the algorithm explained 88% of the baseline variance. CONCLUSIONS: The algorithm goes some way to addressing the problem of harmonizing overweight and obesity prevalence rates for children aged 2-18

    The impact of economic, political and social globalization on overweight and obesity in the 56 low and middle income countries

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    This is the final published version. It first appeared at http://www.sciencedirect.com/science/article/pii/S0277953615001744.Anecdotal and descriptive evidence has led to the claim that globalization plays a major role in inducing overweight and obesity in developing countries, but robust quantitative evidence is scarce. We undertook extensive econometric analyses of several datasets, using a series of new proxies for different dimensions of globalization potentially affecting overweight in up to 887,000 women aged 15e49 living in 56 countries between 1991 and 2009. After controlling for relevant individual and country level factors, globalization as a whole is substantially and significantly associated with an increase in the individual propensity to be overweight among women. Surprisingly, political and social globalization dominate the influence of the economic dimension. Hence, more consideration needs to be given to the forms of governance required to shape a more health-oriented globalization process.The authors were supported by the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence. Funding from the British Heart Foundation, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, and the Wellcome Trust (087636/Z/ 08/Z ESRC: ES/G007462/1), under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged

    Do the outcomes of interventions for the treatment of obesity and overweight in children aged under ten years, delivered by a health care professional, vary by socio-demographic characteristics? A review of Cochrane reviews

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    To review the evidence from five Cochrane systematic reviews of interventions to treat overweight and obesity in children. Applying a social determinants of health perspective and focusing on interventions delivered by health care professionals, for children aged less than ten years, and the challenging phases of interventions including recruitment, adherence and follow-up. The analysis of the social determinants of health is based on the PROGRESS-Plus approach (place of residence, race/ethnicity, occupation, gender, religion, education, socioeconomic status, social capital, age, disability and sexual orientation). The aims are to improve our understanding of the barriers to successful obesity treatment for children, delivered by health care professionals in a setting linked to the provision of health care services, and to identify the characteristics of these children and highlight knowledge gaps. Overarching question: what are the barriers to successful treatment delivered by health care professionals in a setting linked to the provision of health care services for children aged less than ten years, and do these barriers vary by socio-demographic characteristics? Sub-questions: a. What are the best practices management strategies for recruitment to obesity treatments for children aged less than ten years and do these strategies vary by socio-demographic characteristics? b. What are the best practice management strategies for adherence to obesity treatments for children aged less than ten years and do these strategies vary by socio-demographic characteristics? c. What are the best practice management strategies for follow-up in obesity treatment for children aged less than ten years and do these strategies vary by socio-demographic characteristics?This is a protocol for a systematic review

    Primary prevention of overweight and obesity in adolescents: An overview of systematic reviews

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    Summary The aim of this overview of systematic reviews was to summarize evidence from up-to-date reviews of the effectiveness of interventions aimed at preventing overweight and obesity in adolescents aged 10 to 19 years. We searched nine databases for systematic reviews published between January 2008 and November 2019. We used A Measurement Tool to Assess Systematic Reviews (AMSTAR) 2 to assess the quality of reviews, excluding those of critically low quality, and the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool to grade the certainty of included evidence. We included 13 reviews. Three reviews focused on dietary behaviour, six on physical activity, and four on both types of behaviours. Individual-oriented and school-based interventions dominated. Results across reviews showed little or no effect on body mass index, or physical activity levels of adolescents, whereas results from a couple of reviews suggest possibly beneficial effects of public health interventions on dietary behaviours (i.e., consumption of sugar-sweetened beverages). The certainty of evidence was low to very low for all outcomes. Overall, the evidence base for the effect of primary interventions to prevent overweight and obesity in adolescents is weak. In particular, there is a lack of reviews assessing the impact of environmental interventions targeting adolescents, and reviews addressing social inequality are virtually absent from this body of literature

    Sydney principles for reducing the commercial promotion of foods and beverages to children

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    A set of seven principles (the &lsquo;Sydney Principles&rsquo;) was developed by an International Obesity Taskforce (IOTF) Working Group to guide action on changing food and beverage marketing practices that target children. The aim of the present communication is to present the Sydney Principles and report on feedback received from a global consultation (November 2006 to April 2007) on the Principles.The Principles state that actions to reduce marketing to children should: (i) support the rights of children; (ii) afford substantial protection to children; (iii) be statutory in nature; (iv) take a wide definition of commercial promotions; (v) guarantee commercial-free childhood settings; (vi) include cross-border media; and (vii) be evaluated, monitored and enforced.The draft principles were widely disseminated and 220 responses were received from professional and scientific associations, consumer bodies, industry bodies, health professionals and others. There was virtually universal agreement on the need to have a set of principles to guide action in this contentious area of marketing to children. Apart from industry opposition to the third principle calling for a statutory approach and several comments about the implementation challenges, there was strong support for each of the Sydney Principles. Feedback on two specific issues of contention related to the age range to which restrictions should apply (most nominating age 16 or 18 years) and the types of products to be included (31 % nominating all products, 24 % all food and beverages, and 45 % energy-dense, nutrient-poor foods and beverages).The Sydney Principles, which took a children&rsquo;s rights-based approach, should be used to benchmark action to reduce marketing to children. The age definition for a child and the types of products which should have marketing restrictions may better suit a risk-based approach at this stage. The Sydney Principles should guide the formation of an International Code on Food and Beverage Marketing to Children.<br /

    Healthy weight in childhood.

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