Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks

Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight NCD Risk Factor Collaboration (NCD-RisC)

From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions

Weight status and perception of body image in children: the effect of maternal immigrant status

<p>Abstract</p> <p>Background</p> <p>Recent studies have shown that body image perception is an important factor in weight control and may be influenced by culture and ethnicity. The aim of the present study was to assess the relationship between immigrant status of the mother and weight status and body image perception of the child.</p> <p>Methods</p> <p>In total, 2706 schoolchildren (1405 boys and 1301 girls) aged 8–9 years and their mothers participated in a cross-sectional survey in Emilia-Romagna region (northern Italy). Weight and height of the children were measured and Body Mass Index (BMI) was calculated. Actual and ideal body image perception by the children and by the mothers with respect to their children was evaluated according to Collins’ body image silhouettes.</p> <p>Results</p> <p>The BMI values were significantly lower in children of immigrants than in children of Italian mothers (F:17.27 vs 17.99 kg/m²; M:17.77 vs 18.13 kg/m²). The prevalence of overweight/obesity was lower, and the prevalence of underweight higher, in children of immigrant mothers than in those of Italian mothers (overweight- F:21.3 vs 29.1%; M. 28.3 vs 31.4%; underweight- F:5.16 vs 3.84%; M:6.63 vs 2.82%). The children's body image perception was consistent with the differing pattern of nutritional status. In the comparison between actual and ideal figures, the Feel-Ideal Difference Index (FID) scores resulted different between the subsample with foreign-born mother in comparison to the native one (significantly lower in daughters of immigrants) (FID- F: 0.31 vs 0.57; M: 0.35 vs 0.32). There were significant differences in the choice of the ideal figure of the child between immigrant mothers and Italian mothers (FID- F: -0.05 vs 0.19; M: -0.35 vs −0.03): the ideal figure values were higher in the immigrant mothers of male children and lower in the Italian mothers of female children.</p> <p>Conclusion</p> <p>Our results suggest that cultural and behavioral factors linked to ethnicity play an important role in the nutritional status of children and in the perceived and ideal body image.</p

Eating disorders, body image and media exposure among adolescent girls in rural Burkina Faso

OBJECTIVE: Body dissatisfaction and eating disorders (ED) among young females may increase in limited-resource settings as exposure to media and higher-resource cultures increases. We examined ED prevalence and its predictors among adolescent females in rural north-western Burkina Faso. METHODS: Fieldworkers interviewed 696 female adolescents aged 12-20 in the Nouna Health and Demographic Surveillance System (HDSS). ED were evaluated using the Structured Clinical Interview for DSM-5 (SCID-5), self-perceived appearance and body ideal were measured using the Thompson and Gray's Contour Drawing Rating Scale (CDRS) and eating disorder predictors by the Eating Disorder Examination Questionnaire (EDE-Q). We assessed media exposure to magazines, radio, television and the internet. RESULTS: 16% of respondents had a BMI below WHO age-standardized 5th percentile while 4% were above the 85th percentile; most respondents wanted to be larger. DSM-5 criteria for anorexia nervosa (AN) were fulfilled by four of 696 respondents (0.6%), those for bulimia nervosa by none, and those for binge eating disorder by two (0.3%). In multivariable regression, more AN symptoms were associated with greater EDE-Q body dissatisfaction, desiring a thinner body and a history of sexual harassment or assault, but not with media exposure. Conversely, a thinner desired body was associated with greater media exposure, higher BMI z-score and greater EDE-Q disordered eating. CONCLUSION: ED was very rare in rural Burkinabé female adolescents, but factors predictive of ED in higher-resource settings were also predictive here. Our findings suggest that increasing media exposure in resource-limited settings may lead to increased body dissatisfaction, and potentially to increased future ED prevalence