A. F. Hackett

Associations between children's socioeconomic status, weight status, and sex, with screen-based sedentary behaviours and sport participation

OBJECTIVE The objective was to study associations between socioeconomic status (SES), weight status, and sex, with childrens participation in sedentary behaviours and sport. METHODS Children (aged 9-10 years; n = 6,337) completed a questionnaire to establish how long they spent in sedentary behaviours and sport participation during week days and weekend days. Height and weight were measured to calculate body mass index. Associations between dependent and independent variables were investigated using hierarchical loglinear analysis. RESULTS A significantly greater proportion of boys than girls spent > or = 1 h per weekday and weekend day watching television (TV) (p < 0.001), playing video games (p < 0.001), and participating in sport (p < 0.001). TV viewing and video gaming for > or = 1 h per day were inversely associated with SES (p = 0.001), whilst the greatest proportion of children participating in sport for > or = 1 h were in the highest SES quartile (p < 0.001). Overweight girls were more likely than normal weight girls to use the internet for > or = 1 h per weekend day (p < 0.001). CONCLUSIONS Relatively more lower SES children spent time in sedentary behaviours than sport participation. Weight status was not consistently associated with sedentary behaviours. Proportionately more boys than girls watched TV, played video games, and participated in sport, suggesting that boys find time for sedentary behaviours and physical activity. Efforts should be made to address inequalities in the prevalence of sedentary behaviours and sport participation for all children regardless of SES, weight status, or sex.

Cardiorespiratory fitness and body mass index of 9-11-year-old English children: A serial cross-sectional study from 1998 to 2004

Objective:To examine the changes over time in cardiorespiratory fitness and body mass index (BMI) of children.Design:Serial cross-sectional, population-based study.Setting:Primary schools in Liverpool, UK.Participants:A total of 15 621 children (50% boys), representing 74% of eligible 9–11-year olds in the annual school cohorts between 1998/9 and 2003/4, who took part in a 20m multi-stage shuttle run test (20mMST).Main outcome measures:Weight, height, BMI (kg/m2) and obesity using the International Obesity Taskforce definition.Results:Median (95% confidence interval) 20mMST score (number of runs) fell in boys from 48.9 (47.9–49.9) in 1998/9 to 38.1 (36.8–39.4) in 2003/4, and in girls from 35.8 (35.0–36.6) to 28.1 (27.2–29.1) over the same period. Fitness scores fell across all strata of BMI (P<0.001). Moreover, BMI increased over the same 6-year period even among children in fittest third of 20mMST.Conclusion:In a series of uniform cross-sectional assessments of school-aged children, BMI increased whereas cardiorespiratory fitness levels decreased within a 6-year period. Even among lean children, fitness scores decreased. Public health measures to reduce obesity, such as increasing physical activity, may help raise fitness levels among all children – not just the overweight or obese.

The dietary intake of a group of vegetarian children aged 7-11 years compared with matched omnivores

There is a lack of information concerning the diet of vegetarian children. The present study compared the dietary intake of fifty vegetarian children, aged 7-11 years, with fifty matched omnivores. Three 3 d food records were completed by each child at intervals of 6 months. The day after completing the record each child was interviewed to clarify food items and assess portion sizes. Food records were analysed using Microdiet (University of Salford). Finger-prick cholesterol and haemoglobin measurements were taken from a subsample of the group. Only one childs family was a member of the Vegetarian Society and almost one-third of vegetarian children had omnivorous parents (seventeen of fifty subjects). The energy intake (MJ) of the vegetarians was significantly lower than that of the omnivores, 7.6 (SD 1.05) and 8.0 (SD 1.36) respectively; there were no significant differences in Fe or fat intakes. For the vegetarians polyunsaturated:saturated fat ratio (P:S 0.7 (SD 0.04)) and NSP intake (13.8 (SD 0.7) g/d) were significantly higher than those of the omnivores (P:S 0.5 (SD 0.02), NSP 10.3 (SD 0.4) g/d). There was no significant difference in cholesterol measurements (mmol/l) between the two groups: vegetarian 3.5 (SD 0.12), omnivores 3.7 (SD 0.15). The haemoglobin level (g/l) of the vegetarians (11.8 (SD 0.2)) was significantly below that of the omnivores (12.4 (SD 0.2)); 47.5% of the vegetarian children fell below the third percentile of the Dallman reference curves (Dallman & Siimes, 1979). The intake of the vegetarians more closely resembled current recommendations (Department of Health, 1991), although they need to be as aware as omnivores of the need to reduce fat intake. The haemoglobin levels of vegetarian children suggest that they need dietary advice to ensure optimal absorption of Fe.

Promoting healthy weight in primary school children through physical activity and nutrition education: a pragmatic evaluation of the CHANGE! randomised intervention study

BackgroundThis pragmatic evaluation investigated the effectiveness of the Children’s Health, Activity and Nutrition: Get Educated! (CHANGE!) Project, a cluster randomised intervention to promote healthy weight using an educational focus on physical activity and healthy eating.MethodsParticipants (n = 318, aged 10–11 years) from 6 Intervention and 6 Comparison schools took part in the 20 weeks intervention between November 2010 and March/April 2011. This consisted of a teacher-led curriculum, learning resources, and homework tasks. Primary outcome measures were waist circumference, body mass index (BMI), and BMI z-scores. Secondary outcomes were objectively-assessed physical activity and sedentary time, and food intake. Outcomes were assessed at baseline, at post-intervention (20 weeks), and at follow-up (30 weeks). Data were analysed using 2-level multi-level modelling (levels: school, student) and adjusted for baseline values of the outcomes and potential confounders. Differences in intervention effect by subgroup (sex, weight status, socio-economic status) were explored using statistical interaction.ResultsSignificant between-group effects were observed for waist circumference at post-intervention (β for intervention effect =−1.63 (95% CI = −2.20, -1.07) cm, p<0.001) and for BMI z-score at follow-up (β=−0.24 (95% CI = −0.48, -0.003), p=0.04). At follow-up there was also a significant intervention effect for light intensity physical activity (β=25.97 (95% CI = 8.04, 43.89) min, p=0.01). Interaction analyses revealed that the intervention was most effective for overweight/obese participants (waist circumference: β=−2.82 (95% CI = −4.06, -1.58) cm, p<0.001), girls (BMI: β=−0.39 (95% CI = −0.81, 0.03) kg/m2, p=0.07), and participants with higher family socioeconomic status (breakfast consumption: β=8.82 (95% CI = 6.47, 11.16), p=0.07).ConclusionsThe CHANGE! intervention positively influenced body size outcomes and light physical activity, and most effectively influenced body size outcomes among overweight and obese children and girls. The findings add support for the effectiveness of combined school-based physical activity and nutrition interventions. Additional work is required to test intervention fidelity and the sustained effectiveness of this intervention in the medium and long term.Trial registrationCurrent Controlled Trials ISRCTN03863885.

Changes in consumption of sugars by English adolescents over 20 years

OBJECTIVE Dietary surveys of 11- to 12-year-old Northumbrian children in 1980 and 1990 revealed that consumption of non-milk extrinsic sugars (NMES) was 16-17% of energy intake. This study reports dietary sugars consumption in 2000 and compares it with data collected in 1980 and 1990, using identical methods. DESIGN A repeat cross-sectional dietary survey of children aged 1-12 years attending the same schools as in the 1980 and 1990 surveys. SETTING Seven middle schools in south Northumberland. SUBJECTS All children aged 11-12 years old attending the seven schools. METHOD Food consumption was recorded using two 3-day diet diaries. Food composition tables were used to calculate energy and nutrient intakes. NMES, and milk and intrinsic sugars were calculated using previously described methods. RESULTS The numbers of children completing the surveys in 1980, 1990 and 2000 were 405, 379 and 424, respectively; approximately 60-70% of eligible children. Total sugars provided 22% of energy consistently over the three surveys. NMES consumption in 2000 provided 16% of energy compared with 16% in 1980 and 17% in 1990. Sources of NMES changed over the three surveys. NMES from soft drinks doubled from 15 to 31 g day(-1), and from breakfast cereals increased from 2 to 7 g day(-1) over the 20 years. Confectionery and soft drinks provided 61% of NMES. Over 20 years, the proportion of energy from fat decreased by 5% and from starch increased by 4%, creating a welcome tilt in the fat-starch see-saw, without an adverse effect on sugars intake. CONCLUSIONS Consumption of NMES in 2000 was substantially higher than recommended, and there has been little change over 20 years. Continued and coordinated efforts are required at a national, community and individual level to reduce the intake of NMES.

Changes in fitness, body mass index and obesity in 9-10 year olds.

BACKGROUND The prevalence of obesity in children has increased substantially in recent years and, paediatric obesity and poor fitness are risk factors for disease. The present study aimed to assess changes in body mass index (BMI), the prevalence of obesity and changes in aerobic endurance over time in 9-10-year-old schoolchildren. METHODS Participants were recruited by the SportsLinx project from primary schools across Liverpool. Height and weight data were used to calculate BMI. The prevalence of obesity and overweight were estimated using age- and sex-specific cut-off points. Performance on the 20-m multi-stage shuttle runs test (20 mMST) was used as a marker of aerobic endurance. Data were available for 13,418 (6572 boys, 6846 girls) 9-10-year-old children. Analysis of covariance was completed to assess year-on-year changes in BMI controlling for deprivation (IMD) and 20 mMST performance, and 20 mMST performance controlling for IMD and BMI. RESULTS No significant changes in BMI from baseline were observed (P > 0.05). Obesity prevalence reduced in girls (2005 = 10.3%, 2008 = 8.52% in 2008). The data for boys showed no reductions in prevalence (2005 = 6.77%, 2008 = 7.87%). The most recent cohort for boys and two most recent cohorts for girls had lower levels of aerobic endurance than baseline (2004-2005) (P <or= 0.01). CONCLUSIONS The data suggest a plateau in the yearly increases in BMI in 9-10 year olds independent of deprivation and fitness and a declining prevalence of obesity in girls. Levels of aerobic endurance have declined independent of BMI and deprivation. The current obesity interventions in place appear to be having some impact on BMI, but further investment is urged to promote fitness in children.

Changes over 20 years in macronutrient intake and body mass index in 11- to 12-year-old adolescents living in Northumberland.

Monitoring adolescent diets over time enables the assessment of the effectiveness of public health messages which are particularly important in vulnerable groups such as adolescents. In 2000, 424 children aged 11-12 years old completed two 3 d estimated dietary records. On the fourth day one nutritionist interviewed each child to clarify the information in the diary and foods were quantified with the aid of food models. Nutrient intake was calculated using computerised food tables. These children attended the same seven schools in the same Northumberland area as the 11- to 12-year-old children who recorded their diet using the same method in 1980 (n 405) and 1990 (n 379), respectively. Height and weight, and parental occupation were recorded in all three surveys for each child. Height and weight were used to calculate BMI, weight was used to estimate BMR and parental occupation was used to determine social class. Comparing the macronutrient intakes in 2000 with 1980 and 1990, energy intakes (EI) fell in boys (to 8.45 MJ) and girls (to 7.60 MJ). This fall may, at least in part, be due to an increase in low energy reporting. For 1980, 1990 and 2000 the percentage of boys with EI:BMR below 1.1 was 6, 15 and 23 %, respectively; for girls, 3, 14 and 18 %, respectively. Percentage energy from fat was unchanged between 1980 and 1990 but fell to 35 % (about 76 g/d) in 2000, alongside a 3 % increase in percentage energy from starch (30 %). Percentage energy from non-milk extrinsic sugars remained above recommendations (16 %; about 82 g/d). The number of overweight and obese children increased from 11 % to 30 % between 1980 and 2000. Positive changes have occurred in the Northumbrian adolescent diet but social inequalities, reported in previous surveys, remain.

Dietary intake of 9–10-year-old and 11–12-year-old children in Liverpool

OBJECTIVE To describe the eating habits of children in Liverpool and compare two age groups that bridge the transition from primary to secondary school. DESIGN Two cross-sectional studies carried out one year apart using a food intake questionnaire that records whether or not each child claims to have eaten specific marker foods on the previous day. SETTING Primary and secondary schools in Liverpool. SUBJECTS Six hundred and forty-nine children aged 11 or 12 years and 3556 children aged 9 or 10 years. RESULTS Fewer older children ate breakfast (68-82%), especially the girls, and not eating breakfast was associated with eating on the way to school in the younger children. More of the older girls ate nothing at breakfast or on the way to school. Overall, the less desirable foods were reported to have been eaten by more children, of both ages, than the more desirable foods. Fruit, however, was mentioned by most children (69-77%) but the next 10 foods mentioned by most children were all less desirable ones. Only 31% of primary and 21% of secondary children ate both fruit and vegetables but 23% of primary and 26% of secondary children ate neither fruit nor vegetables. Overall, more of the girls of both age groups claimed to have eaten foods that would normally be encouraged. CONCLUSIONS Food choice changes appreciably between primary and secondary school and, in some key respects, for the worse. In particular, far more children of both age groups need to be eating fruit and vegetables every day.

Is overweight and obesity in 9–10-year-old children in Liverpool related to deprivation and/or electoral ward when based on school attended?

OBJECTIVES To determine whether weight problems in children (overweight, obesity and overweight or obesity) were related to deprivation indices when attributed only according to electoral ward of the school attended. To determine whether children with weight problems were more likely to be found in some wards rather than others, and to compare the distribution for boys and girls. DESIGN Retrospective, cross-sectional, observational study. SETTING One hundred and six primary schools from all parts of Liverpool city. SUBJECTS Five cohorts of 9-10-year-old children between 1998 and 2003. MAIN OUTCOME MEASURES Body mass index (BMI) for each child to estimate proportions overweight, obese and overweight or obese according to international criteria. RESULTS Between January 1998 and March 2003, the heights and weights of 7902 boys and 7514 girls were measured and BMI calculated. The prevalence of boys and girls categorised as overweight or obese was very high (1620, 20.6% and 1909, 25.7%, respectively). Prevalence was not related to deprivation and varied between wards only for the girls; some wards had very different prevalence rates for boys and girls (Picton: 59 boys, 23.4%; 106 girls, 36.6%). The most deprived ward did not have a remarkable prevalence of overweight or obesity (Speke: 32 boys, 15.3%; 40 girls, 19.8%). CONCLUSIONS Obesity is a major problem and requires urgent action but targeting intervention on the basis of administrative areas may be very wasteful. Different factors seem to lead to obesity in boys and girls, and attention should be paid to the role of the physical environment.

The prevalence of underweight in 9–10-year-old schoolchildren in Liverpool: 1998–2006

OBJECTIVE To estimate the prevalence of underweight between 1998 and 2006 in Liverpool schoolchildren aged 9-10 years using recently published underweight cut-off points. DESIGN AND SETTING Stature and body mass data collected at the Liverpool SportsLinx projects fitness testing sessions were used to calculate BMI. SUBJECTS Data were available on 26,782 (n 13,637 boys, 13,145 girls) participants. RESULTS Overall underweight declined in boys from 10.3% in 1998-1999 to 6.9% in 2005-2006, and all sub-classifications of underweight declined, in particular grade 3 underweight, with the most recent prevalence being 0.1%. In girls, the prevalence of underweight declined from 10.8% in 1998-1999 to 7.5% in 2005-2006. The prevalence of all grades of underweight was higher in girls than in boys. Underweight showed a fluctuating pattern across all grades over time for boys and girls, and overall prevalence in 2005-2006 represents over 200 children across the city. CONCLUSIONS Underweight may have reduced slightly from baseline, but remains a substantial problem in Liverpool, with the prevalence of overall underweight being relatively similar to the prevalence of obesity. The present study highlights the requirement for policy makers and funders to consider both ends of the body mass spectrum when fixing priorities in child health.