What is a "high" prevalence of obesity? Two rapid reviews and a proposed set of thresholds for classifying prevalence levels.
ABSTRACT: Categories such as "low" and "high" have been used for several decades to describe the prevalence of stunting and wasting in populations of children aged under 5 years. They provide support for public health risk assessment and policy-making, including alerting health departments and aid agencies to national trends and local needs. In the light of the need for monitoring progress to meet globally agreed targets for overweight and obesity, the classification of their prevalence will be a valuable to aid in policy development, to target resources, and to promote public health interventions. This paper reviews the current use of categories to describe obesity prevalence in policy, advocacy, and research literature. Where prevalence categories have been formally proposed, this paper compares their application on large-scale datasets. The paper then develops a set of recommended threshold values to classify prevalence levels for overweight and obesity among children under age 5 years, children aged 5-19 years, and adults.
Project description:BACKGROUND: The prevalence of obesity has increased over the past 3 decades, with a disproportionate growth in excessive weight categories (body mass index [BMI] 35.0-39.9 and BMI ? 40.0). The objective of this paper is to present the data for the past and current prevalence of adult obesity in Canada, together with future estimates. METHODS: We calculated BMIs for adults aged 18 years and older who were not in long-term care using data from Canadian health surveys administered between 1985 and 2011. Calculation of the BMIs was based on self-reported heights and weights. The weight categories were as follows: normal (BMI 18.5-24.9), overweight (25.0-29.9), obese class I (30.0-34.9), obese class II (35.0-39.9) and obese class III (? 40.0). Outcome measures were prevalence of adult obesity according to BMI categories, nationally and provincially. We used regression analysis models to predict future prevalence of adult obesity up to 2019. RESULTS: Between 1985 and 2011, the prevalence of adult obesity in Canada increased from 6.1% to 18.3%. Furthermore, since 1985, the prevalence of obesity in classes I, II and III increased from 5.1% to 13.1%, from 0.8% to 3.6%, and from 0.3% to 1.6%, respectively. Taking into account regional variations, we predict that, by 2019, the prevalence of obesity in classes I, II and III will increase to 14.8%, 4.4% and 2.0%, respectively, and that half of the Canadian provinces will have more overweight or obese adults than normal-weight adults. INTERPRETATION: We found significant increases in the excessive weight categories of obesity, with continued increases predicted for all provinces up to 2019. Provincial variations in obesity prevalence were also significant. To address these projected increases and any subsequent burden on the health care system, a concerted effort must be made by the provinces to focus on the prevention, management and treatment of obesity in Canada.
Project description:BACKGROUND:Global epidemiological transition across various countries have documented the coexistence of undernutrition and overnutrition. South Asian countries are facing this public health hazard in remarkable manner. To enrich the evidence and relation with women's health in the Maldives, this study was undertaken to examine the prevalence and associated factors of underweight, overweight and obesity among reproductive age women. METHODS:This study was conducted utilizing data from the Maldives Demographic and Health Survey 2016-17. After presenting descriptive analyses, multivariable logistic regression analysis method was used to examine the prevalence and associations between different nutritional status categories. These were grouped based on the WHO recommended cut-off value and relevant socio-demographic determinants among reproductive age women. RESULTS:A total weighted sample of 6,634 reproductive age Maldivian women (15-49 years) were included in the analysis. The overall prevalence of overweight and obesity was 63%, while the underweight prevalence was 10%. The younger age group (15-24 years) had a higher prevalence of underweight (26%). On the other hand, an overweight and obesity prevalence of 82.6% was observed among the older age group (35-49 years). Regression analysis showed that residents of the North and Central Provinces, those in the higher quintiles of wealth index, married women and those with parity of more than two children, were all significantly negatively correlated to being underweight. Increased age, being married or separated/divorced/widowed and having more than three children was found to have a significant positive association with overweight and obesity. CONCLUSIONS:Maldives is facing nutritional transition and a major public health hazard demonstrated by the high burden of overweight and obesity and persistence of chronic problem of undernutrition. Surveillance of vulnerable individuals with identified socio-demographic factors and cost-effective interventions are highly recommended to address the persistent underweight status and the emerging problem of overweight/obesity.
Project description:BACKGROUND:In India, the prevalence of overweight and obesity has increased rapidly in recent decades. Given the association between overweight and obesity with many non-communicable diseases, forecasts of the future prevalence of overweight and obesity can help inform policy in a country where around one sixth of the world's population resides. METHODS:We used a system of multi-state life tables to forecast overweight and obesity prevalence among Indians aged 20-69 years by age, sex and urban/rural residence to 2040. We estimated the incidence and initial prevalence of overweight using nationally representative data from the National Family Health Surveys 3 and 4, and the Study on global AGEing and adult health, waves 0 and 1. We forecasted future mortality, using the Lee-Carter model fitted life tables reported by the Sample Registration System, and adjusted the mortality rates for Body Mass Index using relative risks from the literature. RESULTS:The prevalence of overweight will more than double among Indian adults aged 20-69 years between 2010 and 2040, while the prevalence of obesity will triple. Specifically, the prevalence of overweight and obesity will reach 30.5% (27.4%-34.4%) and 9.5% (5.4%-13.3%) among men, and 27.4% (24.5%-30.6%) and 13.9% (10.1%-16.9%) among women, respectively, by 2040. The largest increases in the prevalence of overweight and obesity between 2010 and 2040 is expected to be in older ages, and we found a larger relative increase in overweight and obesity in rural areas compared to urban areas. The largest relative increase in overweight and obesity prevalence was forecast to occur at older age groups. CONCLUSION:The overall prevalence of overweight and obesity is expected to increase considerably in India by 2040, with substantial increases particularly among rural residents and older Indians. Detailed predictions of excess weight are crucial in estimating future non-communicable disease burdens and their economic impact.
Project description:Background:China has experienced rapid economic growth and reduced poverty, but the associated changes of BMI categories of the Chinese population in recent years are unclear. Methods:We collected data from two-round cross-sectional National Health Service Surveys (NHSSs) conducted in China in 2013 and 2018. All family members with BMI available from the households sampled in NHSSs were included. We analyzed the standardized prevalence and changes of obesity and overweight by year, age, sex, and urban-rural area, and further identified risk factors for obesity and overweight. Findings:273,688 individuals were included in 2013 and 25,6304 included in 2018. The standardized prevalence of obesity and overweight in adults were 19.3% (95%CI 19.1-19.4%) in 2013 and 25.6% (95%CI 25.3-25.8%) in 2018, versus 19.4% (95%CI 19·1-19.8%) in children and adolescents in 2013 and 15.8% (95%CI 15.5-16.1%) in 2018. The standardized prevalence of obesity and overweight was 16.9% (95%CI 16.0-17.3%) in young adults aged 19-29 in 2018, 48.2% higher than that in 2013 (11.4% [95%CI 11.0-11.6%]). Although the obesity and overweight prevalence was higher in urban areas, the growth rate in rural areas was 1.8 times higher than that in urban areas. Low education levels, low-income quintiles, marital status, alcohol consumption and former-smoking status were associated with higher obesity and overweight prevalence in adults. Interpretation:The rapidly increasing prevalence in young adults may lead to the growing chronic disease burden in the future, to the detriment of recent economic gains of rural families. Funding:National Health Commission of the People's Republic of China.
Project description:<b>Background:</b> Parental health status had a potential influence on offspring health. This study aimed to investigate the separate associations between paternal and maternal cardiovascular health statuses and the prevalence of childhood overweight and obesity in the offspring. <b>Methods:</b> Data were from a cross-sectional study conducted in seven provinces or cities of China in 2013. A total of 29,317 children aged 6-18 years old and their parents, making up 9,585 father-offspring pairs and 19,732 mother-offspring pairs, were included in the final analysis. Information on parental cardiovascular health status factors (dietary behaviors, body mass index (BMI), smoking, physical activity, hypertension, and diabetes mellitus) was obtained from the structured self-administrated questionnaires. Based on the health status factors, we then generated an ideal cardiovascular health (iCVH) score. The overweight and obesity of children were defined using age- and sex-specific cutoffs based on the International Obesity Task Force criteria. A multilevel log-binomial regression model was used to assess the association between parental cardiovascular health status and prevalence of childhood overweight and obesity in the offspring. <b>Results:</b> The prevalence of pediatric overweight and obesity was 22.0% in the father-offspring subset and 23.8% in the mother-offspring subset, respectively. Fathers with ideal BMI, non-smoking, and absence of hypertension and diabetes, and mothers with ideal BMI, ideal physical activity, and absence of hypertension and diabetes were found to be associated with lower prevalence of overweight and obesity in the offspring. The prevalence of offspring overweight and obesity was significantly decreased with the parental iCVH scores increased. Each additional increase in paternal and maternal iCVH factor was associated with a 30% and 27% lower prevalence of overweight and obesity in the offspring. Compared with children whose parental iCVH scores ≤ 3, offspring whose fathers or mothers met all six iCVH factors had 67% [prevalence ratio (PR): 0.33, 95%CI: 0.25-0.42] and 58% (PR: 0.42, 95%CI: 0.29-0.62) lower prevalence of overweight and obesity, respectively. <b>Conclusions:</b> Parental adherence to iCVH status was associated with a lower prevalence of pediatric overweight and obesity in offspring. Our findings support the intervention strategy that parents should involve in the obesity intervention program for children.
Project description:Introduction:Malnutrition and obesity are a double burden on children in developing countries and could induce higher risks of noncommunicable diseases in the long term. In the big cities of Vietnam, both issues are present and share the issue of nutrition problems; the prevalence of malnutrition in children is gradually decreasing while the prevalence of obesity is increasing rapidly. The paper aims to identify the prevalence of stunting and overweight/obesity in apparently healthy young children in Ho Chi Minh City (HCMC). Methods:A prospective cross-sectional study recruited 12-24-month-old children receiving national vaccination in community health centers in HCMC from February 2016 to July 2017. Sixteen healthcare centers were randomly selected among 8 districts of HCMC. Stunting and overweight were defined by height-for-age z-score <-2 SD and BMI z-score ?+2 SD. Results:A total of 768 children had mean age of 16.8±4.2 months old, 51.7% boys. The prevalence of stunting and overweight/obesity was 8.2% and 10.7%, respectively. Stunting was associated with older age, boys, and low birth weight of children and occupation of mothers (P <0.05). No associated risk factor was observed for overweight/ obesity status. Conclusion:The prevalence of overweight/obesity was higher than the prevalence of stunting in 12-24-month-old children in HCMC. Overweight/obesity would be a public health problem for children in big cities.
Project description:Population monitoring and surveillance of objectively measured child weight data in Canada is limited to national surveys with poor regional applicability, and no healthy weight data are available for children less than 2 years of age. We aimed to determine the prevalence of childhood overweight and obesity using objective measures derived from primary care electronic medical records.Observational data included all height and weight records for children less than 20 years of age, between 2004 and 2013, from 3 Ontario primary care research networks. We calculated body mass index (BMI)-for-age and weight-for-length using the World Health Organization Growth Standards and Reference to assign growth status indicator categories by age group. Descriptive data and prevalence estimates were generated for 2013. We also compared weight-for-length for children less than 2 years of age with a corresponding billing code for known well-child visits.Our study included 8261 children with a corresponding growth status indicator, a sample close to 4 times larger than the national survey sample. In 2013, 28.4% of children aged 5-19 years, and 6% of children aged 0-5 years, were categorized as overweight or obese. Between 2008 and 2013, the total number of 18-month well baby visit billing codes was 1152; 6.9% of this group were categorized as overweight or obese; 19.2% were categorized as having risk of overweight.Primary care electronic medical records show good potential for ongoing population monitoring of overweight and obesity, particularly for very young children for whom early intervention is likely to show the greatest positive health impact.
Project description:To examine the 20-year trends in the combined prevalence of overweight and obesity among children aged 0-6 years between 1995 and 2015 in Harbin, China, we selected altogether 49,553 children aged 0-6 years old by using a multistage stratified cluster sampling methods in Harbin, one provincial capital city in northeast China in 1995, 2005 and 2015. Height and weight information of the children were collected. We used the child growth standards of World Health Organization to calculate the Z-scores for body mass index (BMI). Cut-offs recommended by World Health Organization and International Obesity Task Force were used to define overweight and obesity for each children. We found there is no difference between boys' BMI and girls' among newborns in each survey point (p>0.05), but in older age groups, the BMI of boys was higher than that of girls (p<0.05). From 1995 to 2015, the average BMI was increasing continuously among boys older than 42 months and girls older than 48 months (p<0.01 for linear trend across year) in Harbin. The combined prevalence of overweight and obesity increased from 2.6% in 1995 to 7.6% in 2015. For every 10-year the risk of combined overweight and obesity in children aged 0-6 years increased by 167% (95%CI: 146%, 188%, p<0.01). The combined prevalence of overweight and obesity in most age subgroups showed an increasing trend over time (p<0.01 for trend test across survey year). The age when the combined prevalence of overweight and obesity dramatically increased was earlier in 2015 than that in 2005 and 1995. In conclusion, there was an increasing trend of the combined prevalence of overweight and obesity during the past 20 years in Harbin and the age when the prevalence dramatically increased became earlier. Comprehensive intervention should be undertaken among younger children to prevent and control children's overweight and obesity.
Project description:BACKGROUND:The coexistence of undernutrition (thinness) and overnutrition (overweight/obesity) among children and adolescents is a public health concern in low-middle-income countries. Accurate prevalence estimates of thinness and overweight/obesity among children and adolescents are unavailable in many low-middle-income countries due to lack of data. Here we describe the prevalences and examine correlates of objectively measured weight status among urban and rural schoolchildren in Mozambique. METHODS:A cross-sectional study design was applied to recruit 9-11-year-old schoolchildren (n = 683) from 17 urban and rural primary schools in Mozambique. Body mass index (BMI) was computed from objectively measured height and weight and participants' weight categories were determined using the World Health Organization cut-points. Actigraph GT3X + accelerometers were worn 24 hours per day for 7 days to assess movement behaviours. Multilevel multivariable modelling was conducted to estimate odds ratios and confidence intervals. RESULTS:Combined prevalence of overweight/obesity (11.4%) was significantly higher among urban participants compared to rural participants (5.7%; ?2 = 7.1; p = 0.008). Conversely, thinness was more prevalent among rural (6.3%) compared to urban (4.2%) participants. Passive school commute, not meeting daily moderate- to vigorous-intensity physical activity (MVPA) guidelines, and maternal BMI >25 kg/m2 were associated with overweight/obesity while possessing one or more functional cars at home, maternal BMI >25 kg/m2 and being an older participant were associated with thinness in the present sample. The proportion of total variance in the prevalences of obesity and/or thinness occurring at the school level was 8.7% and 8.3%, respectively. CONCLUSION:Prevalences of thinness, overweight/obesity and other key variables differ between urban and rural schoolchildren in Mozambique. MVPA, active transport and mother's BMI are important modifiable correlates of weight status among Mozambican schoolchildren. Results from this study demonstrate important differences between urban and rural schoolchildren that should not be ignored when designing interventions to manage malnutrition, formulating public health strategies, and interpreting findings.
Project description:BACKGROUND:Overweight and obesity is a severe global health issue in both developed and developing nations. This study aims to estimate the national prevalence of overweight and obesity among school-aged children in Vietnam. METHOD:We conducted a national cross-sectional study on 2788 children aged from 11-14 years old from September to November 2018. We applied the WHO 2007 and IOTF criteria to estimate the prevalence of overweight and obesity among participants. Poison regression analysis with cluster sampling adjustment was employed to assess associated factors with obesity and overweight. Metadata on sociodemographic characteristics, physical measurements, and lifestyle behaviors were also extracted to investigate these factors in association with overweight and obesity prevalence. RESULTS:The prevalences of overweight and obesity in Vietnamese children were 17.4% and 8.6%, respectively by WHO Z-score criteria, and 17.1% and 5.4%, according to the IOTF reference. Using WHO Z-score yielded a higher prevalence of obesity than the IOTF and CDC criteria of all ages and both sexes. The proportions of overweight and obesity were substantially higher among boys than girls across ages. Parental BMI was shown to be a significant factor associated with overweight/obesity status in both girls and boys. Only for boys, age (PR = 0.83, 95% CI 0.76-0.90) and belonging to ethnic minorities (PR = 0.43, 95% CI 0.24-0.76) were significant risk factors for overweight/obesity. CONCLUSION:Our findings indicate a high prevalence of childhood overweight and obesity in Vietnam, especially in boys.