Do substantial BMI reduction episodes among Swedish schoolchildren have any impact on their final height?

AIM: This study investigated whether substantial body mass index (BMI) reductions in Swedish schoolchildren aged seven years to 19 years, caused by disease, healthy or unhealthy behaviour, had any impact on their final height. METHODS: We used height and weight data on 6572 subjects from two nationally representative longitudinal samples of Swedish children born in 1973 and 1981. These provided information on their final height and any BMI reduction episodes. RESULTS: Of the 6572 subjects (50.9% boys), among individuals with information on final height, 1118 had a BMI reduction of 5% and <10%, and 346 had at least one substantial BMI reduction of 10% or more. On a group level, there was no statistically significant difference in the final height of individuals with BMI reductions of 10% or more and those without. The findings were independent of age and the subject's BMI at the start of the reduction episode. However, there were a number of cases where a substantial BMI reduction probably had an impact on the subject's final height. CONCLUSION: Our study found no evidence that a substantial BMI reduction had any impact on final height on a group level, but further analyses of specific case studies are necessary to determine whether substantial BMI reduction might have an impact on final height.

Reported habitual intake of breakfast and selected foods in relation to overweight status among seven- to nine-year-old Swedish children.

AIM: The aim of this study was to examine the reported frequency of breakfast intake and selected food and beverages in the investigated group of Swedish children in comparison with recommended intakes. Furthermore, the study analyses these food habits and some demographic and lifestyle factors in relation to overweight and obesity. METHODS: This cross-sectional study builds on data collected in 2008 and 2010. Measured anthropometric data and parent questionnaire data were collected. A total of 2620 Swedish children (52.1% boys) aged seven to nine years were included. RESULTS: The majority of parents reported that their children (95.4%) had breakfast every day. The majority of children had fresh fruit (84.7%) and vegetables (83.9%) most days a week. Only 1.6% of the children were reported to have fast food and 6.0% to have sugar containing soft drinks, four days a week or more. The prevalence of overweight including obesity (OW/OB) was 17.8% for boys, 18.6% for girls. The odds of being OW/OB was higher among those not having breakfast every day (odds ratio (OR) 1.9, 95% confidence interval (CI) 1.20-2.96), drinking diet soft drink (OR 2.6, 95% CI 1.52-4.42) and skimmed/semi-skimmed milk (OR 1.8, 95% CI 1.37-2.36) four days a week or more. Parents being overweight and having low education levels were also related to a higher risk of their children being overweight. CONCLUSIONS: The parental reports of children's food habits pointed at favourable eating patterns for most investigated children. Breakfast skipping, diet soft drinks and low-fat milk consumption were more frequent among OW/OB children. Longitudinal studies are needed to determine the causal relationships.

Using different growth references to measure thinness and overweight among Swedish primary school children showed considerable variations.

AIM: The study compared how four different growth references determined the prevalence of thinness and overweight, based on height and weight measurements from a nationally representative sample of Swedish children from seven to nine years of age. METHODS: The height and weight measurements of 4518 Swedish schoolchildren aged seven to nine years were carried out in 2008 using a standardised protocol. The prevalence of different degrees of thinness and overweight was calculated using international growth references from the World Health Organization, the International Obesity Task Force and two Swedish growth references from Werner and Karlberg. RESULTS: Depending on which growth reference we used, the prevalence of different degrees of thinness varied from 7.5% to 16.9% for the boys and 6.9% to 13.7% for the girls, while the prevalence of overweight, including obesity and severe obesity, varied from 16.5% to 25.7% for the boys and 18.2 to 25.2% for the girls. There were also significant gender differences depending on the growth reference we used. CONCLUSION: Using four different growth references, two international and two Swedish, produced wide variations in the prevalence of thinness and overweight, together with significant gender differences. In the absence of a global definition, we need both national and international growth references.

A rapid growth rate in early childhood is a risk factor for becoming overweight in late adolescence.

AIM: We evaluated whether body mass index (BMI) and rapid growth in early life were associated with an increased risk of becoming overweight at 16 and 18 years of age. METHODS: The study population comprised all children born in Sweden on the 15th of each month in 1981. Individuals born on the 5th, 10th and 20th of every month were added for counties with low population densities. Information on weight and height was collected from birth up to 18 years of age for 98.6% of the 3537 children identified. RESULTS: Weight at 12 months of age was associated with being overweight at both 16 and 18 years of age. Rapid weight gain from birth to 12 months was associated with higher odds for being overweight later in life, and the weight gain between 18 months and four years of age was the strongest risk factor for being overweight in late adolescence in both sexes. There was no association between a birthweight of <2500 g or >4500 g and being overweight at 16 or 18 years of age. CONCLUSION: Fast growth during early childhood was associated with an increased risk of being overweight later in life, emphasising the importance of early prevention.

Obesity in Swedish schoolchildren is increasing in both prevalence and severity.

PURPOSE: To monitor and describe, on a national level, the development of body mass index (BMI), overweight, and obesity of schoolchildren in Sweden aged 7-18 years over a period of 8 years. METHODS: Longitudinal and cross-sectional studies of two nationally representative cohorts. A representative sample of 3,749 individuals from a birth cohort of 109,663 individuals born in 1973, and another representative sample of 3,158 individuals from a birth cohort of 94,064 individuals born in 1981; 4.5% and 1.6% of those born in 1973 and 1981, respectively, were missing from the sample. Data regarding height and weight from school health records. RESULTS: From age 7-18 year, a strong positive secular change in BMI is found at all ages, and the rate of overweight and obesity is increasing for both boys and girls. Furthermore, obesity is growing more severe. CONCLUSIONS: Nationally representative longitudinal BMI data for two cohorts, in which nonresponse bias is minimized, permitted monitoring and revealed a nationwide strongly positive secular change in BMI in Sweden, over a period of 8 years for individuals aged 7-18 years.

Increasing rate of weight loss among schoolchildren, especially girls, in Sweden.

PURPOSE: This study compared the rates of relative weight loss (body mass index, BMI) among boys and girls, from age 7 to 18 years, in two birth cohorts to determine changing patterns over time. METHODS: Samples from two Swedish national birth cohorts, 1973 and 1981 (all children born on the 15th day of every month), with few missing cases (4.5% and 1.6%, respectively), were studied. Data (height and weight) were collected from school health records and analyzed longitudinally. Episodes of more than 5% reduction in BMI for 3530 boys and girls born in 1973 and 3041 boys and girls born in 1981 were analyzed and compared. RESULTS: An increased rate in 1981 compared with 1973 of relative weight reduction episodes was found for both boys and girls. The increase for girls was most pronounced, started from a higher rate, and was seen in nearly all body weight categories and in all ages. For boys, the reductions increased for all body weight categories in the age interval 7-9 years; otherwise, the pattern was much more heterogeneous. Body weight and reduction of BMI were highly correlated in both cohorts, as more of the overweight than the thinner children reduced their BMI. For girls, the increase in rate reduction between 1981 and 1973 was highest among the thinnest individuals. CONCLUSIONS: Both boys and, especially, girls had an increased rate of weight loss in two longitudinal cohorts. Whether healthy or unhealthy behavior is causing the increase needs to be investigated further.

Head circumference from birth to age 48 months for infants in Sweden.

AIM: To describe the development of head circumference, from birth to age 48 mo, of infants in Sweden. METHODS: Every infant born on the 15th of any month in the 1981 birth cohort, living in Sweden as of 31 December 1989, was studied from birth to age 48 mo (n=3158). By collecting data from child healthcare records and then analysing these data using piecewise linear regression, means and other statistics were produced for every age. Data were analysed for all and with exclusions for low birthweight and those born outside Sweden. RESULTS: From the sample of 3158, data for 3107 infants were collected, making the percentage of missing individuals 1.6%; thus, non-response bias is minimized and high national representativeness is achieved. Summary statistics for head circumference are presented. Comparisons are made to international reference materials, and to previous and current Swedish reference curves. CONCLUSION: For the first time in Sweden, and without selection bias, means and distribution of head circumference measurements are documented longitudinally for a nationally representative sample of infants.

Growth from birth to age 19 for children in Sweden born in 1981: descriptive values.

AIM: To describe Swedish children's growth (i.e. height, weight and body mass index) from birth to age 19 y. METHODS: Every infant born on the 15th of any month in 1981 and living in Sweden as of 31 December 1989 was sampled. Longitudinal data were collected from childhood and school health records, and analysis by piecewise linear regression gave statistical descriptions of height, weight and body mass index for every age group. RESULTS: The data include measurements of 3107 of 3158 sampled children; 1.6% of individuals are missing, so non-response bias is minimal. Thus, statistical descriptions and comparisons with similar data sets can be based on data with unusually high national representativeness. Selected subgroups (i.e. individuals born outside Sweden, suffering from chronic disease causing major growth impairment, or with birthweight <2500 g) deviate in growth pattern, and exclusion of these subgroups increases means and decreases SD for height but only slightly influences summary statistics for weight and body mass index. CONCLUSION: This study represents, without selection bias, the current growth situation among children and adolescents in Sweden, enabling both epidemiological comparisons over time and comparisons with other national surveys.

Data on height and weight from school health records as a national public health surveillance tool: the case of Sweden.

AIM: To investigate the suitability of using routine height and weight data from records within a school health service system, for population monitoring of child and adolescent growth on a national level. METHODS: A longitudinal study from age 7 to 18 years of all children born on the 15th of any month in 1973 and living in Sweden on 31 December 1989 (1,724 girls and 1,855 boys). Data were collected from school health records. RESULTS: Descriptive statistics for height and weight calculated from data obtained from school health records are summarized and compared with previous Swedish studies. The effect of exclusion of children with chronic diseases involving major growth impairment and/or exclusion of children born outside Sweden have a minor impact on the results owing to the relatively small number of excluded children. CONCLUSION: Longitudinal data for somatic growth (height and weight) from age 7 to 18 years from a nationally representative sample of children in Sweden, collected from school health records, can be used for epidemiological monitoring of growth with fewer missing individuals and at lower costs compared with other dedicated studies. Data quality is comparable to similar national surveys. The data are suitable for descriptive analysis of growth and other forms of observational study.