International Cut-offs Research Articles

Physical activity and dietary behaviour in a population-based sample of British 10-year old children: the SPEEDY study (Sport, Physical activity and Eating behaviour: Environmental Determinants in Young people)

BackgroundThe SPEEDY study was set up to quantify levels of physical activity (PA) and dietary habits and the association with potential correlates in 9–10 year old British school children. We present here the analyses of the PA, dietary and anthropometry data.MethodsIn a cross-sectional study of 2064 children (926 boys, 1138 girls) in Norfolk, England, we collected anthropometry data at school using standardised procedures. Body mass index (BMI) was used to define obesity status. PA was assessed with the Actigraph accelerometer over 7 days. A cut-off of ≥ 2000 activity counts was used to define minutes of moderate-to-vigorous PA (MVPA). Dietary habits were assessed using the Health Behaviour in School Children food questionnaire. Weight status was defined using published international cut-offs (Cole, 2000). Differences between groups were assessed using independent t-tests for continuous data and chi-squared tests for categorical data.ResultsValid PA data (>500 minutes per day on ≥ 3 days) was available for 1888 children. Mean (± SD) activity counts per minute among boys and girls were 716.5 ± 220.2 and 635.6 ± 210.6, respectively (p < 0.001). Boys spent an average of 84.1 ± 25.9 minutes in MVPA per day compared to 66.1 ± 20.8 among girls (p < 0.001), with an average of 69.1% of children accumulating 60 minutes each day. The proportion of children classified as overweight and obese was 15.0% and 4.1% for boys and 19.3% and 6.6% for girls, respectively (p = 0.001). Daily consumption of at least one portion of fruit and of vegetables was 56.8% and 49.9% respectively, with higher daily consumption in girls than boys and in children from higher socioeconomic backgrounds.ConclusionResults indicate that almost 70% of children meet national PA guidelines, indicating that a prevention of decline, rather than increasing physical activity levels, might be an appropriate intervention target. Promotion of daily fruit and vegetable intake in this age group is also warranted, possibly focussing on children from lower socioeconomic backgrounds.

Growth Patterns and Obesity Development in Overweight or Normal-Weight 13-Year-Old Adolescents: The STRIP Study

Our goal was to study childhood growth patterns and development of overweight in children who were overweight or normal weight at 13 years of age. This study is part of a prospective atherosclerosis-prevention trial Special Turku Coronary Risk Factor Intervention Project for Children). At 7 months of age, 1062 children were randomly assigned to an intervention group (n = 540) receiving biannual fat-oriented dietary counseling or to a control group (n = 522). Height and weight of the children and their parents were monitored annually. Our study group comprised those children who participated in the 13-year study visit (n = 541). At 13 years of age, the child was classified as overweight (n = 84) if his or her BMI exceeded the international age- and gender-specific overweight criteria. In overweight girls, the annual weight gain increased from 2.8 kg during the third and fourth year of life to 7.5 kg during the 12th year of life, whereas the annual weight gain of the girls who were normal weight ranged from 2.1 to 4.8 kg during the same period. The annual weight gain was similar of overweight boys and in their normal-weight peers until the age of 5 years, but after that it increased from 3.5 to 7.9 kg in overweight and from 2.6 to 5.5 kg in normal-weight boys. The BMI of the girls and boys who were overweight at the age of 13 exceeded the international cutoff point for overweight from the age of 5 and 8 years onward, respectively. The mean BMIs of the mothers and fathers of the overweight children were higher than those of the parents of the normal-weight children. The STRIP intervention had no effect on the examined growth parameters or on parental BMI. The children who were overweight at 13 years of age gained more weight than their normal-weight peers by the age of 2 or 3 years onward. The girls became overweight by the age of 5 years, whereas the boys only after 8 years of age. Parental BMI and steep weight gain in early childhood indicate markedly increased risk for becoming overweight.

Physical Activity and Healthy Weight Maintenance From Childhood to Adulthood

The objective of this study was to determine whether change in physical activity was associated with maintaining a healthy weight from childhood to adulthood. This prospective cohort study examined 1,594 young Australian adults (48.9% female) aged 27-36 years who were first examined at age 9-15 years as part of a national health and fitness survey. BMI was calculated from measured height and weight, and physical activity was self-reported at both time points; pedometers were also used at follow-up. Change in physical activity was characterized by calculating the difference between baseline and follow-up z-scores. Change scores were categorized as decreasing (large, moderate), stable, or increasing (large, moderate). Healthy weight was defined in childhood as a BMI less than international overweight cutoff points, and in adulthood as BMI<25 kg/m(2). Healthy weight maintainers were healthy weight at both time points. Compared with those who demonstrated large relative decreases in physical activity, females in all other groups were 25-37% more likely to be healthy weight maintainers, although associations differed according to the physical activity measure used at follow-up and few reached statistical significance. Although younger males whose relative physical activity moderately or largely increased were 27-34% more likely to be healthy weight maintainers than those whose relative physical activity largely decreased, differences were not statistically significant. In conclusion, relatively increasing and stable physical activity from childhood to adulthood was only weakly associated with healthy weight maintenance. Examining personal, social, and environmental factors associated with healthy weight maintenance will be an important next step in understanding why some groups avoid becoming overweight.

Metabolic syndrome in three ethnic groups using current definitions

According to two current definitions, the prevalence of the metabolic syndrome (MetS) among black Haitians of Montreal was <20%, 30%-36% in Algonquin Indians of Quebec, and >45% in Mexicans of Oaxaca (all aged 35-60 y). Although phenotypes were different, high triglycerides and fasting dysglycemia were good predictors of MetS in all three groups using both definitions. The international cut-offs for abdominal obesity were not predictive of MetS in the Haitian subjects.

Sleep patterns and television viewing in relation to obesity and blood pressure: evidence from an adolescent Brazilian birth cohort

Disruption of circadian rhythms has been associated with obesity in children and adolescents, and with hypertension in adults, in industrialized populations. We examined cross-sectional associations between sleep duration or television viewing and obesity and blood pressure in Brazilian adolescents. The sample consisted of 4452 adolescents aged 10-12 years participating in a prospective birth cohort study in Pelotas, Brazil. Sleep duration and television viewing were determined through questionnaires. Obesity was assessed using international cut-offs for body mass index (BMI), and body fatness by skinfold thicknesses. Blood pressure was measured using a validated monitor. Short sleep duration was associated with increased BMI, skinfolds, systolic blood pressure, activity levels and television viewing. Each hour of sleep reduced BMI by 0.16 kg/m(2) (s.e. 0.04), and was associated with odds ratio for obesity of 0.86 (s.e. 0.04), both P<0.001. Television viewing was associated with increased BMI and skinfolds, and increased blood pressure. The effects of sleep duration and television viewing on obesity were independent of one another. Their associations with blood pressure were mediated by body fatness. Both short sleep duration and increased television viewing were associated with greater body fatness, obesity and higher blood pressure, independently of physical activity level. These associations were independent of maternal BMI, identified in other studies as the strongest predictor of childhood obesity. Our study shows that behavioural factors associated with metabolic risk in industrialized populations exert similar deleterious effects in a population undergoing nutritional transition and suggest options for public health interventions.

Overweight and Cardiovascular Risk Factors in 4- to 18-Year-Olds

Background: The objective of this study was to investigate the relationships between overweight and high waist circumference and cardiovascular risk factors in children. Material and Methods: We carried out a secondary analysis of data from 1,944 participants of the ‘National Diet and Nutrition Survey: young people aged 4–18 years’. Blood pressure and blood lipid levels were compared in overweight versus non-overweight and high versus low waist circumference groups. Overweight was defined using international cut-offs for body mass index. High waist circumference was defined as ≧ 91st percentile of UK waist circumference charts. Analyses were done separately by sex and age group (4–10 and 11–18 years for overweight, and 11–17 years for waist circumference). Results: Overweight and high waist circumference were associated with increased systolic blood pressure, mean arterial pressure, low-density lipoprotein cholesterol (LDLC) and triacylglycerol, and decreased high-density lipoprotein cholesterol (HDLC). Those who were both overweight and had a high waist circumference had the highest blood pressure, plasma LDLC and triacylglycerol, and the lowest plasma HDLC. Conclusion: Overweight and high waist circumference were associated with increased blood pressure and a less favourable lipid profile. Children who were both overweight and had a high waist circumference had the most unfavourable cardiovascular risk profile. Both measurements may be useful in identifying children with increased health risks.

Body mass index of male youths aged 18-20 years of the Han nationality living in different regions of China.

The study was conducted to assess the nutritional status and levels of body mass index (BMI, kg/m2) and to evaluate the geographical distribution of male youths of the Han nationality in China. In total, 60,773 male youths, aged 18-20 years, of the Han nationality, were categorized into underweight, normal-weight, overweight, and obesity according to the international adult BMI cut-offs. Different levels of nutritional status and BMI of male youths of the Han nationality were compared among different areas. The mean BMI for the whole country was 20.6 in urban areas and 20.0 in rural areas. BMI increased from 20.1 among 18-year old youths to 20.5 among 20-year old youths. The prevalence of underweight among the male youths was 21.6%, while the prevalence of overweight and obesity were 4.6% and 0.6% respectively. For urban youths, the prevalence of underweight, overweight, and obesity were 21.0%, 6.8%, and 1.1% respectively, while these were, respectively, 21.9%, 3.3%, and 0.3% for rural youths. The nutritional status of the male youths in North-China was at the highest level (21.1) among the six areas, and the prevalence of underweight, overweight, and obesity were 14.3%, 9.1%, and 1.4% respectively. The highest prevalence of underweight was 29.8% in the North-West region, and the lowest prevalence of overweight was 2.2% in the South-Middle region, while the lowest prevalence of obesity was 0.2% in the South-West region. The nutritional status of the male youths was significantly different among different areas. Underweight was still prevalent in all male youth groups. Nonetheless, overweight was more prevalent among urban youths than among rural youths and was more prevalent in the North region than in the South region.

Excessive body weight is associated with additional loss of quality of life in children with asthma

Asthma and excessive body weight frequently coexist, whereas the exact relationship between the 2 diseases is unknown. To study whether asthma combined with excessive body weight has a greater effect on quality of life in children than the separate effects of asthma or excessive body weight alone. In a cross-sectional design, 1758 school children (age 7-10 years) participated: 4 study groups were composed of children with asthma and with/without excessive body weight, and healthy controls with/without excessive body weight. Diagnosis of asthma was defined by either a doctor's diagnosis or by core questions of the International Study of Asthma and Allergies in Childhood questionnaire in combination with either reversible airway obstruction or bronchial hyperresponsiveness. Excessive body weight was defined by using international cutoff points for body mass index. Quality of life was evaluated by the Pediatric Asthma Quality of Life Questionnaire. For all domains of quality of life, children with both asthma and excessive body weight had lower scores than children with either asthma alone or excessive body weight alone. Compared with healthy controls, the score was 25% lower in children with asthma and excessive body weight, 14% lower in children with asthma and normal weight, and only 1% lower in overweight controls. Excessive body weight is associated with an additional decrease in quality of life in children with asthma. Clinicians should be aware of the interaction between asthma and excessive body weight and the effect on quality of life and should give extra attention to children with both conditions.

Validity of Parentally Reported Weight and Height for Preschool-Aged Children in Belgium and Its Impact on Classification Into Body Mass Index Categories

The aim of this study was to evaluate the validity of parentally reported weight and height values for preschool-aged children (3-7 years of age) in Belgium and the accuracy of BMI classifications using those data. The subjects were 297 preschool-aged children (157 boys and 140 girls). A questionnaire with questions about height and weight was distributed to the children and completed by their parents. Nurses of the Centres for Pupils Counselling conducted anthropometric measurements by following standardized procedures. National and international age- and gender-specific BMI cutoff values were used to determine BMI categories. Mean differences between reported and measured values for weight (-0.57 kg) and BMI (-0.51 kg/m2) were statistically significant, although small. For height, the mean difference (0.14 cm) was not statistically significant. When national and international BMI cutoff values for overweight were used, sensitivity values were 47% and 44%, respectively, and specificity values were 94% and 95%. Among all children requiring nutritional advice on the basis of being overweight or obese, more than one half of the overweight children and >75% of the obese children would be missed with the use of parentally reported weight and height values. Conversely, 70% of the children being classified as underweight with the use of these reported data could be encouraged wrongly to gain weight. The bias of parent-reported BMI values was significantly greater when weight and height were both guessed, rather than being measured at home. Our results show the inaccuracy of parentally reported weight and height values in Belgium for classifying preschool-aged children into BMI categories. Therefore, accurate measurements of weight and height should be encouraged in studies in which BMI of children is a variable of interest.

Pedometer-Determined Physical Activity and Body Composition in New Zealand Children

The objectives of this study were to examine current levels of pedometer-determined physical activity in a multiethnic sample of New Zealand children and to investigate associations among weekday and weekend step counts, body mass index (BMI), waist circumference (WC), and percentage body fat (%BF). A total of 1115 children (536 boys, 579 girls) aged 5-12 yr wore sealed multiday memory pedometers for three weekdays and two weekend days. The ethnic composition of the sample was 49.2% European, 30.0% Polynesian, and 16.5% Asian, with 4.3% from other ethnicities. BMI was determined from height and weight, and %BF was measured using hand-to-foot bioelectrical impedance analysis. Participants were classified as normal weight, overweight, or obese using international BMI cutoff points (4), and into normal or central fat distribution groups using national WC standards (28). The 90th percentile of %BF for each age and sex subgroup was used to identify normal and high body fatness. Mean step counts for this sample were 16,133 +/- 3,864 (boys) and 14,124 +/- 3,286 (girls) on weekdays, and 12,702 +/- 5,048 (boys) and 11,158 +/- 4,309 (girls) on weekends. Significant differences in step counts were observed between weekdays and weekends, boys and girls, and among age, ethnic, and socioeconomic groups. Analysis of variance revealed stronger associations between step counts and %BF category than between step counts and BMI or WC groups. This study provides evidence of a link between daily step counts and body fatness in children. Our results also suggest that the promotion of physical activity during the weekend is a key priority for young New Zealanders.

Metabolic syndrome in Turkish children and adolescents

The aim of this study was to determine the prevalence and phenotype of metabolic syndrome in Turkish children and adolescents. We adapted the National Cholesterol Education Program Adult Treatment Panel III criteria of metabolic syndrome to children and adolescents. Using the international cutoff points and percentiles, we determined 10- to 17-year-old Turkish children and adolescents with high blood pressure, high triglyceride (TG), low high-density lipoprotein cholesterol (HDL-C), fasting glucose of 100 mg/dL or greater, and elevated body mass index corresponding to overweight or obesity. We examined 1385 apparently healthy students between the ages of 10 to 17 years from Ankara, Turkey: 4.9% of the subjects were overweight or obese; 29.2% had either low HDL-C and/or high TG levels; and 15.7% had either systolic or diastolic blood pressure above the 95th age-, sex-, and height-specific percentile. Thirty students (2.2%) had metabolic syndrome by having 3 or more risk variables. Metabolic syndrome was nearly 10 times more common among overweight and obese students (21%), compared with lean students. Components of metabolic syndrome such as high blood pressure and high TG, and low HDL-C levels were common among Turkish children and adolescents. Strategies should focus on early detection and treatment of these risk variables in Turkish children.

Secular Trends in Overweight and Obesity among Japanese Children and Adolescents

The prevalence of childhood obesity has increased worldwide. It is a major public health concern in Japan as well. There are, however, few studies on the trends of childhood obesity in Japan. PURPOSE: To examine the trends of overweight and obesity in Japanese youth using international BMI cutoffs. METHODS: In Japan, a large-scale nationwide, cross- sectional survey has been carried out every year under the direction of the Ministry of Education, Culture, Sports, Science and Technology. Standing height and body mass are measured in the survey, and the frequency matrices on height (every 1 cm) and mass (every 1 kg), but not the raw data, have been published. For the present study, we used the matrix data for 5-, 8-, 11-, 14-, and 17-year-old males and females from the 1978, 1983, 1988, 1993, 1998, and 2003 surveys. The body mass index (BMI) in each cell of the matrix was calculated from the body mass (kg) of the cell divided by square of the standing height (m) of the cell. Then the BMI of each cell was compared with sex- and age-specific international BMI cutoffs presented by Cole et al (2000). When the BMI of a cell exceeded the international cutoffs for overweight or obesity, we identified the subjects included in that cell as overweight or obese, respectively. The prevalence of overweight and obesity were obtained from the sum of frequencies included in the cells where the BMI exceeded the international cutoffs. RESULTS: The percentage (%) of overweight and obesity increased over the 25 years, as shown in the Table. The highest percentages were seen at age 11 for overweight and at age 8 for obesity in 2003, for both males and females. Mean values for standing height, body mass, and BMI gradually increased over time. However, the modes of BMI were almost constant during the 25 years, suggesting that the increasing percentage of youth having high BMI above a cutoff is not attributed to secular increase in body size or secular trends towards earlier maturation.TableCONCLUSION: A substantial increase over time in overweight and obesity was observed in Japanese youth, particularly for younger children aged 8 and 11 years.

Relationship between BMI, physical fitness, and motor skills in youth with mild intellectual disabilities

The negative impact of obesity on physical fitness and motor abilities has been documented in youth of various ages; however, this issue has not been explored in youth with mild intellectual disabilities (ID). Youth with ID are considered more overweight, less physically fit, and less motor proficient than peers without ID, so it is important to determine if these variables are associated in this population. The purpose of this study was to examine the relationship between body mass index (BMI), physical fitness, and motor skills in a large sample of youth with mild ID. A systematic, stratified sampling method was used to select 444 youth with mild ID, aged 6-18 years, from eight special education schools in Hong Kong. Physical fitness was assessed using items from the national Hong Kong assessment: 6- (ages 6-8 years) or 9- (ages 9-18 years) minute run, sit-up, isometric push-up, sit and reach, and sum of skinfold. Functional motor skills were assessed in 244 youth from the fitness sample using the Test of Gross Motor Development-II. Subjects were categorized into normal or overweight/obese BMI groups based on international cutoff points. Approximately 20% of the sample was classified as overweight/obese (average BMI normal = 17.47+/-2.69; overweight/obese = 24.78+/-4.05). ANCOVA controlling for age and gender revealed group differences in the run (P = 0.001) and push-ups (P = 0.05), but not in the motor or other fitness variables. After controlling for age and gender, BMI was correlated with the run (r = -0.27, P < 0.001) and push ups (r = -0.18, P = 0.008). Age and gender were entered as the first block in hierarchical regression and accounted for most of the variance in all dependent variables, except sit and reach. The inclusion of BMI in the second block added to the model for run and push-ups only (deltaR2 run = 0.04, push-ups = 0.03, P<0.001). Overweight/obesity is minimally associated with aerobic fitness and muscular strength in youth with mild ID. BMI did not impact other fitness measures (sit-up, sit and reach) or motor skills in the sample. The undesirable level of overweight/obesity in this sample requires increased attention and immediate intervention.

Prevalence Of Overweight And Obesity In Flemish Adults

PURPOSE Overweight is an epidemic problem in the United States but also in Europe there has been a very rapid increase in the prevalence of overweight in the last decade. The aim of this study was to describe the prevalence of overweight and obesity in Flemish adults. METHODS Data are from the research project “Investigation of the current quantitative and qualitative pattern of physical activity, sport participation, physical fitness and general health of the Flemish population” as part of the Policy Research Centre Sport, Physical Activity and Health. In total, 3978 men and 3596 women were measured for different anthropometrical indicators of overweight: body weight, BMI, waist circumference, sum of 4 skinfolds (biceps, triceps, suprailiac and subscapular) and body fat percentage (Durnin-Womersley). Men and women were analysed separately and divided in eleven five-year interval groups: 18–24, 25–29, ???,70–74 years. The international BMI cutoff scores were used for the classification in overweight (BMI>25kg/m2) and obese adults (BMI>30kg/m2). RESULTS In general, the anthropometrical indicators of overweight increase with age in both sexes. There was a small decrease in the oldest age group for men in all measurements. About 1 out of 7 men and 1 out of 8 women in the 18–24 age group are overweight. There is a strong increase in the prevalence of overweight with age, especially between the age of 18 and 34 in men (from 14 to 45%) and between the age of 18 and 29 in women (from 13 to 29%). The overall prevalence of overweight is higher for men than for women. In the age group 35–39, 49% of men and 28% of women are overweight. In the oldest age group about 7 out of 10 are overweight in both sexes. The prevalence of obesity in the youngest group is only 1.06% in women and 2.87% in men, with increasing prevalence of obesity with age. In the age group 45–49 the prevalence of obesity reaches about 10% in both sexes. Highest prevalence of obesity is seen in the 65–69 age group in men (18.56%) and in the 55–59 age group in women (19.62%). CONCLUSIONS The prevalence of overweight and obesity among Flemish adults is normal in the youngest age group but increases dramatically in the older age groups in both sexes. The prevalence of overweight is lower among Flemish compared to US Caucasian adults but is similar for the adults above 60 years of age (NHANES 1999–2000). Compared with the US, the overall prevalence of obesity is lower for Flemish adults in all age groups. Our data suggest that preventive action by the Flemish government is necessary for Flemish adults. This project is supported by the Flemish Government.

Total energy expenditure (H218O), physical activity level and milk output of lactating rural Bangladeshi tea workers and nontea workers

To assess the total daily energy expenditure (TDEE), milk output and physical activity level (PAL) of chronically malnourished lactating women using the doubly labelled water method (DLW). Prospective, longitudinal study designed to assess the extent of malnutrition and energetics of lactating tea workers and nontea workers. North-east Bangladesh on women working and living in the same tea estates. Of an original cohort of 150 lactating women, 30 were selected to participate in this study when they were at about 12 months postpartum. One mother subsequently dropped out. On day 1 each women provided a urine sample, was administered a dose of DLW and 6 h later provided another sample. Further urine samples were collected for 21 subsequent days. In addition, every 5 days the mother provided a milk sample and at the same time her baby provided a urine sample. Mean (s.d.) BMI was 17.4 (1.63). Mean TDEE and PAL were significantly higher in workers than nonworkers (8.42 (1.38) and 6.83 (2.09) MJ/day, P = 0.02 and 1.92 (0.34) and 1.59 (0.44), P = 0.03, respectively). Mean milk output was similar in the two groups (672 (180) ml and 749 (189) ml in workers and nonworkers, respectively). Based on international BMI cutoffs, 79% of mothers were suffering from some degree of chronic energy deficiency. A total of 35% of workers and 17% of nonworkers were engaged in strenuous physical activity. The mean milk output of both workers and nonworkers was not different and was high especially as most of the mothers were about 12 months postpartum. No relationship was found between menses return and any of the variables studied. World Health Organization, Nestle Foundation, UNICEF.

Standardizing Anthropometric Measures in Children and Adolescents with New Functions for Egen

A new function for egen has been developed to allow transformation of child anthropometric data to z-scores using the LMS method and the reference data available from the 1990 British Growth Reference and the 2000 US CDC Growth Reference. An additional function allows for children to be categorized according to body mass index (weight/height2) using international cutoff points recommended by the Childhood Obesity Working Group of the International Obesity Taskforce.

Screening for childhood obesity: international vs population-specific definitions. Which is more appropriate?

The objectives of this study are: (1) to study the relation between body mass index (BMI), percentage-weight-for-height (PWH) and percentage body fat (PBF) in Singaporean Chinese children; (2) to assess the applicability of an international definition of obesity (the International Obesity Task Force (IOTF) BMI) as a screening tool to detect childhood obesity, as compared with the current Singapore population-specific definition using PWH. A total of 623 Chinese children aged 6-11 y (321 males, 302 females) were recruited from a school by proportionate (40%) stratified random sampling. BMI and PWH were calculated from weight and height, while PBF was derived using leg-to-leg bioelectrical impedance analysis. The strength of association among the three indices of obesity was assessed using Spearman's correlation coefficient. Obese children were defined as those above the 95th percentile of PBF in each age-gender-specific group. Sensitivity and specificity of IOTF-BMI cutoff values and PWH cutoff values were compared by testing their ability to correctly identify obese children. All three indices correlated well with one another (BMI:PWH r=0.83, BMI:PBF r=0.87, PWH:PBF r=0.76). Prevalence of obesity was lower using IOTF-BMI cutoffs (6.9%) than using PWH cutoffs (16.4%). The sensitivity and specificity of IOTF-BMI cutoff values were 75.0 and 96.0%, respectively, with sensitivity differing between boys (83.3%) and girls (66.6%) (P=0.35). In comparison, PWH cutoff values had higher sensitivity (91.6%) but lower specificity (86.6%), with no significant difference between the genders. IOTF-recommended BMI cutoff values had low sensitivity and may underestimate the local prevalence of childhood obesity. For screening purposes, we recommend that population-specific measures rather than international cutoff values be used.

The utility of the international child and adolescent overweight guidelines for predicting coronary heart disease risk factors

The purpose of this study was to assess the association between the international overweight cutoffs for children and youth and coronary heart disease risk factors. The sample included 410 boys and 337 girls 9–18 years of age from the Québec Family Study. Participants were classified as normal weight or overweight using the international BMI cutoffs, and into normal and elevated risk groups based on the 90th percentile of sex-specific age-adjusted risk factors [blood pressure, fasting total cholesterol (CHOL), LDL-C, HDL-C, CHOL/HDL-C, triglycerides, glucose, and physical work capacity]. Overweight participants had between 1.6 and 9.1 times the risk of elevated risk factors compared to normal-weight participants. Further, boys and girls with four or more risk factors were 19 and 43 times more likely to be overweight, respectively, compared to participants with no risk factors. The results add evidence that the international cutoffs are related to health risks in youth, supporting the adoption of the guidelines.

Spinal overload: a concern for obese children and adolescents?

Heavy children require stronger bones than leaner children. The present cross-sectional observational study was undertaken to examine the magnitude of compensatory increases in the spinal bone mineral content (BMC) and area shown by overweight and obese children and adolescents. Vertebral area and BMC of lumbar vertebrae L2-L4 were measured by dual-energy X-ray absorptiometry in 202 boys and 160 girls aged 3-19 years. Subjects were categorized as of normal weight, overweight or obese using international cutoffs for body mass index. Compared with children of healthy weight our overweight and obese children had lower vertebral BMC for their bone area, body height, body weight and pubertal development: ratios and 95% CI for overweight and obese groups were 0.92 (95% CI 0.87-0.97) and 0.88 (95% CI 0.80-0.96) for girls and 0.96 (95% CI 0.91-1.02, NS) and 0.87 (95% CI 0.78-0.96) for boys, respectively. Spinal area was low in overweight and obese girls compared with girls of healthy weight but overweight and obese boys had enlarged their vertebral area appropriately for their increased body size. We conclude that during growth overweight and obese children do not increase their spinal BMC to fully compensate for their excessive weight. Limiting excessive adiposity in childhood and adolescence should help to avoid excessive loading and stresses on the lumbar spine.

Physical Activity and Television Viewing Linked to Body Mass Index among Philippine High School Students: Signaling of an Emerging Epidemic of Obesity?

The major purpose of this study was to determine whether body mass index (BMI) was associated with reports of vigorous physical activity and television viewing among a sample of more than 3,000 Philippine high school students. In addition, the International Task Force on Obesity's new cutoff points to these adolescents' self-reports were applied to calculations of BMI based on self-reported height and weight in order to determine the prevalence of overweight and obesity among this sample of Filipino adolescents. Results showed that Filipino boys and girls who were the most frequent participants in vigorous physical activity (3 or more times a week) had significantly lower BMI when compared to those who were physically active less frequently. Conversely, Filipino boys and girls who viewed five or more hours of television during an average school day had significantly higher BMI than those who watched less television. The percentage of Philippine students in this study above the international cut offs for overweight (6.5 percent of boys and 5.7 percent of girls) and obesity (1.6 percent of boys and 1.8 percent of girls) was considerably lower than what has been found in studies of youth in developed Western nations. However, the adopting of Western lifestyle habits, including increased recreational inactivity (e.g., television viewing, video games, and surfing the Internet) and decreased participation in vigorous physical activity, could signal an emerging epidemic in this developing nation.