Changes In Body Mass Index Distribution Research Articles

Changes in the age-specific body mass index distribution among urban children between 2002 and 2018 in Changsha, China.

BackgroundIt had been reported that the increase in the prevalence of childhood overweight and obesity in several developed countries over the decade was largely a consequence of changes in the upper end of the body mass index (BMI) distribution. We speculated that the change in BMI distribution among Chinese children is different from that in developed countries. Therefore, we investigated the changes in the BMI distribution among urban children in Changsha, China.MethodsA secondary data analysis of the 2002 and 2018 Annual Survey on Students’ Constitution and Health from Yuhua District, Changsha City, China was performed. The BMI distribution of children aged 6–15 years (n=72,061) was examined by calculating the BMI value at 5th, 50th, 85th, and 95th percentiles. Differences in the BMI value at the 5th, 50th, 85th, and 95th percentiles between 2002 and 2018 according to age and sex were calculated.ResultsFrom 2002 to 2018, the standardized rate of underweight decreased from 6.9% to 3.4%, whereas that of obesity increased from 6.1% to 13.8%. The BMI of the population increased over the 16-year period. The greatest change between the years was seen in the 85th percentile, and moderate changes were seen in the 5th and 50th BMI percentiles. Also, the greatest changes in the BMI percentiles were evident at age 12–14 years.ConclusionsThe whole spectrum of BMI distribution among school-aged children shifted over the 16-year study period, although the increases were more marked in the upper than lower percentiles. Health professionals and health policymakers should develop strategies and interventions aimed at preventing adverse health effects caused by this change.

Weight development from age 13 to 30years and adolescent socioeconomic status: The Norwegian Longitudinal Health Behaviour study.

ObjectivesTo describe the weight development and model change in body mass index (BMI), and to examine the association of adolescent socioeconomic status (SES) with change in BMI distribution in a cohort followed from adolescence through adulthood.MethodsParticipants (n = 924) from western Norway were surveyed seven times from age 13 to 30 (1990–2007). BMI was based on self-reported height and weight. Quantile regression analyses were used to model change in weight development and to investigate associations between SES (measured by parental education) and change in BMI distribution. The analyses were adjusted for curvilinearity in BMI development, gender and relevant health behaviours.ResultsBody mass index increased over time with the greatest increase in the 90th percentile. No significant associations between change in BMI and SES were observed at any of the percentiles (10th, 25th, 50th, 75th or 90th).ConclusionsThose in the upper BMI percentile gained more weight than those in the lower percentiles indicating that these might need targeted interventions. Further investigation of the association of change in BMI and SES with better quality data might be warranted.

Age-specific changes in BMI and BMI distribution among Australian adults using cross-sectional surveys from 1980 to 2008.

Research efforts have focused mainly on trends in obesity among populations, or changes in mean body mass index (BMI), without consideration of changes in BMI across the BMI spectrum. Examination of age-specific changes in BMI distribution may reveal patterns that are relevant to targeting of interventions. Using a synthetic cohort approach (which matches members of cross-sectional surveys by birth year) we estimated population representative annual BMI change across two time periods (1980 to 1989 and 1995 to 2008) by age, sex, socioeconomic position and quantiles of BMI. Our study population was a total of 27349 participants from four nationally representative Australian health surveys; Risk Factor Prevalence Study surveys (1980 and 1989), the 1995 National Nutrition Survey and the 2007/8 National Health Survey. We found greater mean BMI increases in younger people, in those already overweight and in those with lower education. For men, age-specific mean annual BMI change was very similar in the 1980s and the early 2000s (P=0.39), but there was a recent slowing down of annual BMI gain for older women in the 2000s compared with their same-age counterparts in the 1980s (P<0.05). BMI change was not uniform across the BMI distribution, with different patterns by age and sex in different periods. Young adults had much greater BMI gain at higher BMI quantiles, thus adding to the increased right skew in BMI, whereas BMI gain for older populations was more even across the BMI distribution. The synthetic cohort technique provided useful information from serial cross-sectional survey data. The quantification of annual BMI change has contributed to an understanding of the epidemiology of obesity progression and identified key target groups for policy attention-young adults, those who are already overweight and those of lower socioeconomic status.

Changes of Body Mass Index among Young Men in Brazil over Two Decades

Aim: To evaluate changes in the body mass index (BMI) of young Brazilian men in two regions of Brazil at opposing socioeconomic extremes in order to determine whether the changes in BMI distribution had different patterns over two decades. Methods: We selected a sample of 6,706,386 males as the study population, aged 18 years, from individuals that were conscripted into the army from 1980 to 2005. The percentiles of the BMI distribution from 1980 to 2005 were calculated. For each percentile, the slope of a linear regression curve was tested for increases or decreases over time (p < 0.05). Results: The secular trends in BMI showed the largest increases at the upper ends of the distributions. However, the lower values of the percentiles in both regions did not change over time. The 10th percentile for the southeast region and the 20th percentile in the northeast did not change. Conclusion: No significant differences in the lower percentile values were found for the BMI distribution of young Brazilian males during the period 1980–2005, suggesting that around 10% of young Brazilian males living in the most developed regions, such as the southeast, are protected against obesity.

Trends of body mass index distribution in schoolchildren in Sendai, Japan, 1989–2003

Accumulating evidence indicates a strong association between obesity and health problems. Childhood obesity increases the risk of adulthood obesity. Although it is reported that the number of obese children in Japan has increased, it is unclear whether the obesity index distribution pattern has changed. To clarify this distribution pattern, we analyzed the changes in the body mass index (BMI) of primary (6th grade, 12 years old) and junior high (3rd year, 15 years old) schoolchildren in the city of Sendai during the period from 1989 to 2003. Our department has accumulated information on the height and body weight of all the schoolchildren in the city of Sendai. BMI was calculated using both the height and body weight data. The change in median BMI for 15 years had a slightly upward trend every year with both gender and school year. Although the BMI distribution showed that there was little or no change over time in the lower (10th and 25th) percentiles, the increases in the 75th and 90th percentiles were more marked than that in the 50th percentile in primary school children. On the other hand, there was only a small increase in BMI in the 3rd year of junior high school. Our results indicated that the changes in BMI distribution were concentrated at the upper end of the distribution in primary school children. The shifts in the value of high percentiles might be due to effect modification of the corresponding exposure by another environmental exposure or genetic predisposition. It is suggested that the factors causing this change influenced only part of this population, and affected individuals might represent a susceptible subpopulation of the exposed children.:

Overweight Trends among Children Enrolled in the New York State Special Supplemental Nutrition Program for Women, Infants, and Children

The objective of this study is to describe overweight trends in a large, multiethnic, low-income population of preschool children by race/ethnicity and examine cohort changes in body mass index (BMI) distribution. Cross-sectional data were collected January 1 through March 31, every year, from 1989 to 2003. Subjects were children aged 2 to 4 years participating in the Special Supplemental Nutrition Program for Women, Infants, and Children in New York State. The prevalence of overweight (BMI ≥95th age- and sex-specific percentile of the 2000 Centers for Disease Control and Prevention growth charts) was calculated for each year. Least squares regression compared trends in prevalence by race/ethnicity. Changes in BMI distribution were assessed graphically. Overweight prevalence increased 33% (12% to 16%). Prevalence was highest for Hispanics and lowest for non-Hispanic whites. Rates of increase (0.28 percentage points per year) were the same for Hispanic, non-Hispanic black, and non-Hispanic white children. The BMI distribution shifted toward higher values for all children studied; for 3- and 4-year-old children, the difference increased as BMI increased, indicating that, in 2003, the heaviest children were considerably heavier than the heaviest children were in 1989.

Influence of social class on time trends in BMI distribution in 5-year-old French children from 1989 to 1999.

To assess the prevalence of obesity and changes in body mass index (BMI) distribution between 1989 and 1999 in 5-y-old children, and to study the influence of parental socioeconomic status on these parameters. Two cohorts of children in the final year of nursery school (in the city of Lille, France) were enrolled in 1989 (705 children: mean age=5.6+/-0.4 y) and 1999 (1258 children: mean age=5.6+/-0.5 y). Weight and height were measured, and data about parental occupation were collected during a school medical examination. International Obesity Task Force cutoff points were used to define overweight and obesity. Parental occupation was classified into four categories. The prevalence of obesity increased from 1.8 to 4.9%, and the prevalence of overweight rose from 9.6 to 16.9%. Mean-difference plots allowed qualitative comparisons of the BMI distribution between the surveys: for children from the highest social classes, there was no change in BMI; for children from intermediate classes, there was a up-shift only in the upper part of the distribution with the heaviest children becoming heavier still; finally, for children from the lowest class, there was an increase in BMI across the entire population. This study of the changes in BMI distribution gives greater insight into the 'obesity epidemic'. Our results show the influence of an interaction between genetic and environmental factors. The increase in BMI in the upper part of the distribution suggests that this is a population with a high degree of susceptibility, whereas the increase in BMI across the whole population in the lowest social class suggests a strong influence of the environment on this group and thus the necessity of appropriate, preventive measures.