Impact of a 6-month family-based weight management programme on child food and activity behaviours: short-term and long-term outcomes of the PEACH™ intervention

BACKGROUND

The PEACH™ randomized controlled trial measured changes to children's food and activity behaviours following participation in a weight management programme. We have previously reported a 10% reduction in body mass index z-score at intervention end (6-month post-baseline) that was maintained to 24 months with no further intervention for the full study sample.

OBJECTIVES

The objective of the study is to report changes in food and activity outcomes in the full sample at (i) the end of the 6-month intervention and (ii) 24-month post-baseline (18-month post-intervention).

METHODS

Changes in dietary and activity outcomes were assessed over time (baseline: n = 169, 8.1 ± 1.2 years, body mass index z-score 2.72 ± 0.62). Dietary intake was assessed using the Child Dietary Questionnaire, and times spent active and sedentary were assessed using a study-specific questionnaire. Linear mixed models were used.

RESULTS

There were significant time effects for all Child Dietary Questionnaire scores and activity and sedentary behaviours in the expected direction. Significant sex effects were observed for fruit and vegetable and sweetened beverages scores and for time spent in small screen-based activity.

CONCLUSIONS

This is one of few child weight management studies to report short-term and long-term behaviour outcomes. It demonstrates that an intervention promoting food and activity behaviours consistent with guidelines can achieve modest changes, mediating improvements in relative weight.

The differential effect of socio-economic status, birth weight and gender on body mass index in Australian Aboriginal Children

BACKGROUND

Adult Aboriginal Australians have 1.5-fold higher risk of obesity, but the trajectory of body mass index (BMI) through childhood and adolescence and the contribution of socio-economic factors remain unclear. Our objective was to determine the changes in BMI in Australian Aboriginal children relative to non-Aboriginal children as they move through adolescence into young adulthood, and to identify risk factors for higher BMI.

METHODS

A prospective cohort study of Aboriginal and non-Aboriginal school children commenced in 2002 across 15 different screening areas across urban, regional and remote New South Wales, Australia. Socio-economic status was recorded at study enrolment and participants' BMI was measured every 2 years. We fitted a series of mixed linear regression models adjusting for age, birth weight and socio-economic status for boys and girls.

RESULTS

In all, 3418 (1949 Aboriginal) participants were screened over a total of 11 387 participant years of follow-up. The prevalence of obesity was higher among Aboriginal children from mean age 11 years at baseline (11.6 vs 7.6%) to 16 years at 8 years follow-up (18.6 vs 12.3%). The mean BMI increased with age and was significantly higher among Aboriginal girls compared with non-Aboriginal girls (P<0.01). Girls born of low birth weight had a lower BMI than girls born of normal birth weight (P<0.001). Socio-economic status and low birth weight had a differential effect on BMI for Aboriginal boys compared with non-Aboriginal boys (P for interaction=0.01). Aboriginal boys of highest socio-economic status, unlike those of lower socio-economic status, had a higher BMI compared with non-Aboriginal boys. Non-Aboriginal boys of low birth weight were heavier than Aboriginal boys.

CONCLUSIONS

Socio-economic status and birth weight have differential effects on BMI among Aboriginal boys, and Aboriginal girls had a higher mean BMI than non-Aboriginal girls through childhood and adolescence. Intervention programs need to recognise the differential risk for obesity for Aboriginal and non-Aboriginal boys and girls to maximise their impact.

Television advertising, not viewing, is associated with negative dietary patterns in children

BACKGROUND

Children's exposure to unhealthy food marketing is a contributor to poor diets and weight gain. Television food advertising, in particular, has been the focus of research and policy discussions.

OBJECTIVES

We aimed to quantify the specific impact of television advertising, as distinct from television viewing generally, on children's usual diet. Methods Four hundred seventeen Australian children aged 10-16 participated in an online survey, which assessed television viewing habits and consumption of 12 frequently advertised unhealthy foods/drinks. Consumption of these foods/drinks was dichotomized (less weekly, weekly or more) and summed (1 point for each item consumed weekly or more) to give cumulative consumption scores.

RESULTS

After adjusting for age and socioeconomic status, there was strong evidence of an increase in unhealthy food score (P < 0.001), drink score (P = 0.002) and food/drink combined score (P < 0.001), with increasing commercial television viewing.

CONCLUSIONS

The link between television viewing and poor diet was strongest for children who watched the most commercial television, and those who were actually exposed to advertisements embedded within programs. This association between advertisement exposure and poor diet emphasizes the need for public policy intervention to reduce children's food advertising exposures.

Longitudinal trends in global obesity research and collaboration: a review using bibliometric metadata

The goal of this study was to understand research trends and collaboration patterns together with scholarly impact within the domain of global obesity research. We developed and analysed bibliographic affiliation data collected from 117,340 research articles indexed in Scopus database on the topic of obesity and published from 1993-2012. We found steady growth and an exponential increase of publication numbers. Research output in global obesity research roughly doubled each 5 years, with almost 80% of the publications and authors from the second decade (2003-2012). The highest publication output was from the USA - 42% of publications had at least one author from the USA. Many US institutions also ranked highly in terms of research output and collaboration. Fifteen of the top-20 institutions in terms of publication output were from the USA; however, several European and Japanese research institutions ranked more highly in terms of average citations per paper. The majority of obesity research and collaboration has been confined to developed countries although developing countries have showed higher growth in recent times, e.g. the publication ratio between 2003-2012 and 1993-2002 for developing regions was much higher than that of developed regions (9:1 vs. 4:1). We also identified around 42 broad disciplines from authors' affiliation data, and these showed strong collaboration between them. Overall, this study provides one of the most comprehensive longitudinal bibliometric analyses of obesity research. This should help in understanding research trends, spatial density, collaboration patterns and the complex multi-disciplinary nature of research in the obesity domain.

Dairy food consumption, blood pressure and retinal microcirculation in adolescents

BACKGROUND AND AIMS

The relationship between dairy food consumption and dietary calcium intake, and vascular risk factors during adolescence remains unclear. We aimed to prospectively assess whether dairy food consumption (milk, cheese, yoghurt) is associated with blood pressure (BP) and retinal microvascular signs among adolescents.

METHODS AND RESULTS

As many as 2353 and 1216 participants aged 12 and 17, respectively, were examined. Longitudinal analyses involved 888 subjects with complete baseline and follow-up data. Dairy consumption was assessed from validated semi-quantitative food frequency questionnaires. BP information was collected and retinal vessel caliber was quantified from digital photographs using computer software. In girls, after multivariable adjustment, each serve/day increase in total dairy intake was concurrently associated with 1.04 (p = 0.03) and 1.10 mm Hg (p = 0.02) decreases in mean diastolic and arterial BP, respectively. Also in girls, each serve/day increase in cheese intake over 5 years was concurrently related to 7.18 (p = 0.001), 5.28 (p = 0.002) and 5.79 mm Hg (p = 0.001) decrease in mean systolic, diastolic and arterial BP, respectively. Among girls, each 100 mg/day increase in dietary calcium intake was associated with a concurrent 0.5 (p = 0.01) and 0.3 mm Hg (p = 0.02) decrease in mean systolic and arterial BP, respectively. Cross-sectionally, adolescents in the highest versus lowest tertile of yoghurt intake had ∼ 1.3 μm wider retinal arterioles (p = 0.05) and ∼ 2.0 μm narrower venules (p = 0.04).

CONCLUSIONS

Consumption of dairy products, particularly cheese, could have a beneficial effect on BP, particularly among girls.

Waist-to-height ratio and cardiometabolic risk factors in adolescence: findings from a prospective birth cohort

OBJECTIVE

To examine the associations between body mass index (BMI) and waist-to-height ratio (WHtR) measured in childhood and adolescence and cardiometabolic risk factors in adolescence.

METHODS

Secondary data analysis of the Avon Longitudinal Study of Parents and Children, a population based cohort. Data from 2858 adolescents aged 15.5 (standard deviation 0.4) years and 2710 of these participants as children aged 7-9 years were used in this analysis. Outcome measures were cardiometabolic risk factors, including triglycerides, low density lipoprotein cholesterol, high density lipoprotein cholesterol, insulin, glucose and blood pressure at 15 years of age.

RESULTS

Both BMI and WHtR measured at ages 7-9 years and at age 15 years were associated with cardiometabolic risk factors in adolescents. A WHtR ≥0.5 at 7-9 years increased the odds by 4.6 [95% confidence interval 2.6 to 8.1] for males and 1.6 [0.7 to 3.9] for females of having three or more cardiometabolic risk factors in adolescence. Cross-sectional analysis indicated that adolescents who had a WHtR ≥0.5, the odds ratio of having three or more cardiometabolic risk factors was 6.8 [4.4 to 10.6] for males and 3.8 [2.3 to 6.3] for females. The WHtR cut-point was highly specific in identifying cardiometabolic risk co-occurrence in male children and adolescents as well as female children (90 to 95%), but had poor sensitivity (17 to 53%). Similar associations were observed when BMI was used to define excess adiposity.

CONCLUSIONS

WHtR is a simple alternative to age and sex adjusted BMI for assessing cardiometabolic risk in adolescents.

Effects of nutrient content claims, sports celebrity endorsements and premium offers on pre-adolescent children's food preferences: experimental research

OBJECTIVES

To assess pre-adolescent children's responses to common child-oriented front-of-pack food promotions.

METHODS

Between-subjects, web-based experiment with four front-of-pack promotion conditions on energy-dense and nutrient-poor (EDNP) foods: no promotion [control]; nutrient content claims; sports celebrity endorsements (male athletes) and premium offers. Participants were 1302 grade 5 and 6 children (mean age 11 years) from Melbourne, Australia. Participants chose their preferred product from a randomly assigned EDNP food pack and comparable healthier food pack then completed detailed product ratings. Child-oriented pack designs with colourful, cartooned graphics, fonts and promotions were used.

RESULTS

Compared to the control condition, children were more likely to choose EDNP products featuring nutrient content claims (both genders) and sports celebrity endorsements (boys only). Perceptions of nutritional content were enhanced by nutrient content claims. Effects of promotions on some product ratings (but not choice) were negated when children referred to the nutrition information panel. Premium offers did not enhance children's product ratings or choice.

CONCLUSIONS

Nutrient content claims and sports celebrity endorsements influence pre-adolescent children's preferences towards EDNP food products displaying them. Policy interventions to reduce the impact of unhealthy food marketing to children should limit the use of these promotions.

Parental history of hypertension and dietary intakes in early adolescent offspring: a population-based study

We investigated the cross-sectional association between parental history of hypertension and dietary intakes among early adolescent schoolchildren. A total of 1845 participants aged 12 years had complete data on diet and parental medical history, and thus they were included in the final analyses. Dietary data were assessed from validated semi-quantitative food-frequency questionnaires. Parents completed questionnaires about their medical conditions. Cases where the biological mother and/or father had hypertension were classified as positive parental history of hypertension. After multivariable adjustment, participants with positive versus negative parental history of hypertension had 33% greater likelihood of consuming soft drinks ⩾1 per week. Boys with a parental history versus boys without a parental history of hypertension consumed more energy-dense, nutrient-poor foods: 379.4 g per day and 318.0 g per day, respectively, P=0.02. Girls with a positive versus a negative parental history consumed more vegetables: 164.1 versus 142.6 g per day, P=0.01. Significant associations were not observed between those with and those without a positive parental history in mean dietary intakes of carbohydrates, fats, sugars and sodium. Children with a positive parental history of hypertension were 67% more likely to simultaneously engage in three unhealthy lifestyle behaviors (excessive recreational screen viewing, high consumption of snacks and and high consumption of soft drinks). Parental hypertension was associated with unhealthy dietary behaviors among offspring, including higher consumption of soft drinks and energy-dense, nutrient-poor foods.

Transition to adult care in adolescent obesity: a systematic review and why it is a neglected topic

Transition in pediatric health care involves the purposeful, planned movement of patients from pediatric to adult services. Following the significant increases in long-term survival of chronic childhood diseases in the 1980s, transition has taken on an increasing importance in the management of these chronic diseases. In Australia, there is a conspicuous lack of programs/guidelines for transitioning adolescents with obesity. The authors sought to determine if this is an international phenomenon that should be addressed. This study aimed to identify what formal transition services or guidelines exist internationally for adolescents with overweight/obesity. Two systematic reviews of the published and 'gray' literature were implemented via searches of relevant databases, search engines and websites. The primary review eligibility criteria were documents published between 1982 and 2012 including any aspect of transitioning adolescents with overweight/obesity from pediatric to adult weight management services. The secondary review included current clinical practice guidelines/statements on pediatric obesity management published between 1992 and 2012, and transition recommendations contained within. Non-English language documents were excluded. Relevant text from eligible documents was systematically identified and extracted, and a qualitative synthesis of the data was prepared. Overall, 2272 unique records were identified from the literature searches. Three eligible articles were identified by the primary review. The secondary review identified 24 eligible guidelines/statements. In total, six of the identified documents contained information on transition in adolescent obesity-the most detailed documents provided only a brief statement recommending that transition from pediatric to adult weight management services should take place. In conclusion, internationally there is an absence of published intervention programs/policies, and brevity of clinical guidance and expert opinion, on the transition of adolescents with obesity making this a priority research area. Consideration is given to the reasons why transition in adolescent obesity is a neglected topic.

Research priorities in 2012 for the effective management of childhood obesity

In 2010, the Management Stream of the Australasian Child and Adolescent Obesity Research Network (ACAORN) undertook a Delphi survey asking 'What research questions remain to be addressed in the effective management of child and adolescent obesity?' Members of ACAORN, the Child and Adolescent Obesity Clinics of Australasia Network (CAOCOA-Net) and attendees at the Child Obesity symposium at the annual scientific meeting for the Australian and New Zealand Obesity Society (ANZOS) contributed to three rounds of survey development. Although reasonable concordance in ratings was evident for all 10 questions, 'determining the best strategies for long-term weight management' and 'how best to support the primary healthcare system to achieve these strategies' were clearly identified as the highest research priorities. Other priorities included 'how best to identify the right children with whom to intervene' and 'managing factors which impact on service delivery'. Identifying priority research areas from those working in the field offers the opportunity to stimulate research collaboration and provide justification for funding applications.

Shifting curves? Trends in thinness and obesity among Australian youth, 1985 to 2010

OBJECTIVE

To describe 25-year trends in the prevalence of ≤Grade 2 thinness and obesity among Australian children by sex, age and socioeconomic (SES) background.

METHODS

Cross-sectional surveys of New South Wales school-aged children aged 6.0-16.9 years conducted in 1985-1997-2004-2010 (n = 19 434). Height/weight were measured, and thinness and obesity were defined by international standards. SES was derived from children's residential postcode using the Australian Bureau of Statistics' Index of Relative Socioeconomic Disadvantage, most proximal to the survey year.

RESULTS

Since 1985, the prevalence of thinness has not varied by survey year. Age was not associated with thinness; however, thinness was lower among middle SES boys, compared with high SES (OR: 0.45, 95%CI: 0.21, 0.97). The prevalence of obesity trebled between 1985 and 1997 (1.7% vs. 5.1% P = 0.000); however, since 1997, obesity prevalence has not significantly changed. Since 1997, obesity was higher among younger compared with older girls (OR: 2.11, 95%CI: 1.48, 3.00) and SES was inversely associated with obesity in boys (OR: 2.05, 95%CI: 1.44, 2.92) and girls (OR: 1.86, 95%CI: 1.27, 2.74).

CONCLUSIONS

The apparent plateau in child obesity is a welcome finding; however, the SES gradients are of concern. If the obesity stabilization is associated with the impact of multiple lifestyle behavioural interventions, the findings suggest obesity programmes have done 'no harm', but potentially the dose/delivery of interventions has not been sufficient or appropriate to reduce child obesity levels.

A synthesis of existing systematic reviews and meta-analyses of school-based behavioural interventions for controlling and preventing obesity

Schools are an attractive and popular setting for implementing interventions for children. There is a growing body of empirical research exploring the efficacy of school-based obesity prevention programs. While there have been several reviews on the topic, findings remain mixed. To examine the quality of evidence and compare the findings from existing systematic reviews and meta-analyses of school-based programs in the prevention and control of childhood obesity. This paper systematically appraises the methodology and conclusions of literature reviews examining the effectiveness of school-based obesity interventions published in English in peer-reviewed journals between January 1990 and October 2010. Eight reviews were examined, three meta-analyses and five systematic reviews. All of the reviews recognized that studies were heterogeneous in design, participants, intervention and outcomes. Intervention components in the school setting associated with a significant reduction of weight in children included long-term interventions with combined diet and physical activity and a family component. Several reviews also found gender differences in response to interventions. Of the eight reviews, five were deemed of high quality and yet limited evidence was found on which to base recommendations. As no single intervention will fit all schools and populations, further high-quality research needs to focus on identifying specific program characteristics predictive of success.

The prevalence of increased central adiposity in Australian school children 1985 to 2007

The epidemic of obesity as measured by body mass index (BMI) maybe plateauing. However, studies using skin-fold and waist circumference measurements suggest that BMI may underestimate changes in fatness in children. In this study we examine changes in waist circumference and waist-to-height ratio (WHtR) in Australian children between 1985 and 2007, by undertaking secondary data analysis of three national data sets. The mean waist circumference z-score for boys increased from -0.02 (95% CI -0.05 to 0.01) in 1985, to 0.33 (0.26 to 0.40) in 1995 and 0.41 (0.35 to 0.47) in 2007 and was greater (P<0.001) than the increase in BMI z-score. The increase in mean waist circumference z-score for girls was greater (P<0.001) than boys and increased from -0.02 (0.05 to 0.01) in 1985, to 0.33 (0.26 to 0.41) in 1995 and to 0.57 (0.51 to 0.63) in 2007. The number of children with a WHtR ≥ 0.5 increased from 8.6% in 1985, to 13.6% in 1995 and 18.3% in 2007. Between 1985 and 2007 central adiposity increased at a faster rate than total adiposity, particularly in girls. The secular increase in waist circumference and WHtR is concerning as measures of central adiposity are associated with metabolic and cardiovascular risk.

The role of parents in pre-adolescent and adolescent overweight and obesity treatment: a systematic review of clinical recommendations

The study aims to describe clinical recommendations (i) on the role of parents in both pre-adolescent and adolescent overweight and obesity treatment; (ii) to health professionals on how to involve parents in paediatric overweight and obesity treatment and (iii) to identify deficiencies in the associated literature. A systematic literature review was conducted in March 2010 to identify clinical practice guidelines, position or consensus statements on clinical management of paediatric overweight or obesity, developed by a national or international health professional association or government agency, and endorsed for current use. Relevant clinical recommendations in these documents were identified via a screen for the words 'parent', 'family' and synonyms. Twenty documents were included. Most documents emphasized the importance of involving parents or the family in paediatric overweight and obesity treatment with approximately a third of documents providing separate recommendations on the role of parents/family for pre-adolescents and adolescents. The documents varied markedly with regard to the presence of recommendations on parent/family involvement in the various components of lifestyle interventions or bariatric surgery. Almost half of the documents contained recommendations to health professionals regarding interactions with parents. High-quality research is needed on age-specific techniques to optimize the involvement of parents and family members in paediatric overweight and obesity treatment.

Relationship between a range of sedentary behaviours and blood pressure during early adolescence

Very few studies have explored links between physical activity, sedentary behaviours and blood pressure (BP) in early adolescence. We aimed to assess the association between a range of sedentary activities (screen time, television (TV) viewing, computer usage, video game usage and time spent in homework or reading) and BP in schoolchildren. Eligible year-7 students (2353/3144, mean age 12.7 years) from a random cluster sample of 21 Sydney schools were examined during 2003-2005. Parents and children completed detailed questionnaires of activity. BP was measured using a standard protocol and high BP was defined using published guidelines. Height and weight were measured, and body mass index (BMI) calculated. After adjusting for age, sex, ethnicity, parental education, height, BMI and time spent in physical activity, each hour per day spent in screen time, watching TV and playing video games was associated with a significant increase in diastolic BP of 0.44 (P=0.0001), 0.99 (P<0.0001) and 0.64 mm Hg (P=0.04), respectively. In contrast, each hour per day spent reading was associated with a decrease of 0.91 (P=0.01) and 0.69 mm Hg (P=0.02) in systolic and diastolic BP, respectively. Our results indicate that addressing different types of sedentary activities could be a potentially important strategy to reduce the prevalence of elevated BP in children.

Components of primary care interventions to treat childhood overweight and obesity: a systematic review of effect

The primary care setting presents an opportunity for intervention of overweight and obese children but is in need of a feasible model-of-care with demonstrated effectiveness. The aims were to (i) identify controlled interventions that treated childhood overweight or obesity in either a primary care setting or with the involvement of a primary healthcare professional and (ii) examine components of those interventions associated with effective outcomes in order to inform future intervention trials in primary care settings. Major health and medicine databases were searched: MEDLINE, CINAHL, EMBASE, Cochrane Reviews, CENTRAL, DARE, PsychINFO and ERIC. Articles were excluded if they described primary prevention interventions, involved surgical or pharmacological treatment, were published before 1990 or not published in English. Twenty-two papers describing 17 studies were included. Twelve studies reported at least one significant intervention effect. Comparison of these 12 interventions provides evidence for: training for health professionals before intervention delivery; behaviour change options (including healthy diet, activity and sedentary behaviour); effecting behaviour change via a combination of counselling, education, written resources, support and motivation; and tailoring intensity according to whether behavioural, anthropometric or metabolic changes are the priority. These components are practicable to future intervention studies in primary care.

A review of electronic interventions for prevention and treatment of overweight and obesity in young people

The objective of this systematic review is to provide a qualitative comparison of interactive electronic media interventions for the prevention or treatment of obesity and/or obesity-related behaviours in children and adolescents. Literature searches of 12 databases from the earliest publication date until March 2010 were conducted. Twenty-four studies in which children and/or adolescents interacted with electronic interventions delivered as adjunct or sole interventions for the prevention or treatment of obesity and/or obesity-related behaviours met the inclusion criteria. Fifteen focussed on obesity prevention and nine on treatment interventions. The average study quality design score was 45%. Most studies demonstrated some form of significant outcome (e.g. reported changes in dietary and/or physical activity behaviours) in participants receiving interactive electronic interventions, with 11 out of 15 studies leading to positive changes in measured or reported adiposity outcomes. In 87% of studies, the effects of interactive electronic interventions were not separately evaluated from other intervention components. These results should be viewed with caution because of the overall poor quality of the studies. Studies were mostly conducted in the USA, largely in minority populations, and the direct transferability of interventions to other populations is unclear. Further high quality research is needed in this area to accurately inform the evidence base.

Treatment of clinical insulin resistance in children: a systematic review

The objective of this study was to evaluate the effectiveness of interventions aimed at improving clinical insulin resistance and/or pre-diabetes in children. This study is a systematic review and meta-analysis. Five electronic databases were searched for randomized controlled trials of at least 2-months' duration. The outcomes were fasting insulin, homeostasis model assessment of insulin resistance (HOMA-IR), body mass index (BMI) and adverse outcomes. Four randomized controlled trials were identified. All compared the effect of 6 months of metformin plus or minus lifestyle intervention with placebo plus or minus lifestyle intervention. After pooling results from three trials, the mean difference after 6 months favoured the intervention with a statistically significant mean decrease in fasting insulin, HOMA-IR and BMI of 9.6 µU mL(-1) (95% confidence interval [CI]: 6.3, 13.0 µU mL(-1) ; I(2) = 76%), 2.7 (95% CI: 1.7, 3.6; I(2) = 74%) and 1.7 kg m(-2) (95% CI: 1.1, 2.3 kg m(-2) ; I(2) = 75) respectively. Mild gastrointestinal symptoms were reported in 19% (2-29%; median and range) of participants taking metformin. Metformin improves markers of insulin sensitivity and reduces BMI in children and adolescents with clinical insulin resistance or pre-diabetes. Stronger evidence from high-quality studies of longer duration and larger sample size are required before clinical conclusions about the optimal treatment protocol in this population can be drawn.

Obesity and low-grade inflammation: a paediatric perspective

Childhood obesity is a major public health problem. Low-grade inflammation, a hallmark characterizing adult obesity, may be a pivotal mechanism linking obesity to its numerous systemic complications, with adipose tissue depots secreting and producing inflammatory mediators and visceral fat displaying an increased inflammatory profile. While knowledge is relatively scarce regarding the importance of the adipose tissue inflammation process in children, identifying its contribution in childhood obesity and the associated influences of age, sex, weight status, growth, and adipose depot phenotypes are crucial for understanding physiopathology and implementing early intervention strategies. We review the latest research linking obesity and inflammation in childhood focusing on serum inflammatory markers and the effectiveness of lifestyle interventions in improving systemic inflammation. Generally, there are significant correlations between body mass index and increased c-reactive protein and decreased adiponectin levels in children; these levels tend to be improved in interventions resulting in approximately 5% weight loss, regardless of the type or length of intervention. There is a need for further research measuring other inflammatory mediators (e.g. tumour necrosis factor (TNF)-alpha, IL-6, IL-8) and histological studies examining immune cell infiltration in adipose tissue depots in obese children.

Efficacy of weight loss drugs on obesity and cardiovascular risk factors in obese adolescents: a meta-analysis of randomized controlled trials

Weight loss drugs have been developed to reduce the comorbidities associated with excess weight. We conducted a meta-analysis of the efficacy of orlistat and sibutramine on weight, body mass index, waist circumference and cardiovascular risk factors in overweight adolescents. MEDLINE and the Cochrane Library were searched for relevant articles using MESH terms and keywords. Studies were included if they had reported quantitative estimates and standard deviations of the association between each weight loss drug and weight, with information on at least one cardiovascular risk factor. A total of eight trials (three orlistat and five sibutramine) with information on 1391 individuals was included in the present analysis. The mean decrease in weight between the intervention and control groups was 5.25 kg (95% confidence interval: 3.03-7.48) after a minimum follow-up of 6 months. There was evidence of statistical heterogeneity between the studies (I(2) = 76%) that was no longer apparent after exclusion of trials of orlistat (mean weight decrease = 5.32 kg; I(2) = 38%). There was little evidence that treatment was associated with adverse effects on cardiovascular risk factors but this requires verification from future large trials with longer study follow-up.

Predictors of time spent outdoors among children: 5-year longitudinal findings

BACKGROUND

Given the importance of physical activity for health and age-related declines in physical activity, understanding influences on related behaviours, such as time outdoors, is crucial. This study aimed to understand individual, social and physical environmental influences on longitudinal changes in urban children's time outdoors.

METHODS

The time children spent outdoors in 2001, 2004 and 2006 (aged 5-6 and 10-12 years at baseline) was reported by their parents (n=421). In 2001, individual, social and physical environmental factors were self-reported by parents. Generalized estimating equations examined longitudinal relationships between baseline predictors and average change in time outdoors over 5 years.

RESULTS

Children's time outdoors significantly declined over time. "Indoor tendencies" inversely predicted time outdoors among younger and older boys, and younger girls. Social opportunities positively predicted time outdoors among younger boys, while "outdoor tendencies" positively predicted time outdoors among older boys. Parental encouragement for activity positively predicted time outdoors among younger and older girls, while lack of adult supervision for active play outdoors after school inversely predicted time outdoors among older girls and older boys.

CONCLUSION

Individual (indoor and outdoor tendencies) and social factors (social opportunities, parental encouragement and parental supervision) predicted children's time outdoors over 5 years. Interventions targeting reduced indoor tendencies, increased outdoor play with others, and increased parental encouragement and supervision are warranted.

A systematic review of school-based intervention studies for the prevention or reduction of excess weight among Chinese children and adolescents

The aim of this paper was to conduct a systematic review of intervention studies in China aimed at the prevention or control of excess weight gain among children and adolescents. Two Chinese databases (The China Full Text Database and Wanfang Database) and two English databases (Medline and Meditext) were searched with keywords for intervention studies published between 1990 and 2006. Data were extracted on aspects of study quality, methodology and effectiveness of interventions. Quality assessment was conducted using a previously established assessment tool. Twenty-two studies were included, of which 17 were conducted among overweight and/or obese children and/or adolescents. Interventions strategies varied across studies but the majority focused on improving the level of knowledge, physical activity levels and/or diet of overweight children and adolescents. Most studies reported a beneficial effect of the intervention with one or more of the study outcomes, but all of the studies had serious, or moderate, methodological weaknesses. None of the trials identified by this systematic review demonstrated convincing evidence of the efficacy of any single intervention for the prevention of overweight and obesity in children and adolescents from Mainland China. Future intervention trials should address the methodological weaknesses identified in this review.

Waist-to-height ratio: a simple option for determining excess central adiposity in young people

Waist circumference is recommended as a means of identifying people at risk of morbidity associated with central adiposity. Yet, there are no universally agreed cut-points to determine when a waist circumference is too large in young people. In this study we examined the relation between sex- and age-specific waist circumference cut-points, the waist-to-height ratio (WHtR) cut-point of <0.5 and cardiovascular disease (CVD) risk clustering in 164 young people, mean age 14.9+/-0.2 years (mean+/-s.d.). In total 19 (11.6%) of the sample were identified as having CVD risk clustering. These young people were significantly (P<0.001) heavier and had higher body mass index (BMI) and waist circumference z-scores compared to those without CVD risk clustering. The WHtR cut-point of 0.5 estimated CVD risk clustering to a similar extent to sex- and age-adjusted cut-points for waist circumference and BMI. Young people with excess central adiposity (WHtR> or =0.5) were 11 times (OR 11.4, P<0.001), more likely to have CVD risk clustering compared to those who did not have excess central adiposity. The WHtR has several advantages; it is easy to calculate, does not require sex- and age-specific centiles and as has been previously suggested, it is a simple message, easily understood by clinicians and families, to 'keep your waist circumference to less than half your height'.

Comparison of metabolic syndrome prevalence using six different definitions in overweight pre-pubertal children enrolled in a weight management study

OBJECTIVES

To assess the implications of variation in Metabolic Syndrome (MS) definition (biochemical and anthropometric indicators) on MS prevalence estimates in a population of overweight and mildly obese children.

DESIGN

Cross-sectional study.

SUBJECTS

Ninety-nine (64 girls) overweight or mildly obese, but otherwise healthy, pre-pubertal 6-9-year olds recruited for a randomized controlled trial of weight management.

MEASURES

Height, weight and waist circumference were measured with BMI and waist z-scores calculated. Fasting cholesterol and fractions, glucose and insulin were measured, together with systolic and diastolic blood pressure (BP). Anthropometric and metabolic indicators were classified as normal or elevated using adult- or child-specific cut points with clustering of MS indicators also assessed using two adult and three child-specific definitions.

RESULTS

A total of 0-4% of subjects were classified with MS when adult definitions were applied. This increased to between 39 and 60% using child-specific definitions, varying according to whether hyperinsulinaemia was central to the MS classification. Systolic BP, triglycerides, total cholesterol, high-density lipoprotein cholesterol and waist z-score increased across insulin quartiles (P<0.05). The use of body mass index and waist circumference in the MS definition classified the same subjects.

CONCLUSIONS

The classification of MS in children depends strongly on the definition chosen, with MS prevalence estimates higher if insulin is part of the definition and child-specific cut points for metabolic indicators are used. Hyperinsulinaemia and MS are common consequences of childhood obesity but they are not commonly part of the assessment or management plan for weight management in children. There is a need for the establishment of normal insulin ranges and consistent definition of MS in childhood and adolescence.

Outcome data from the LEAP (Live, Eat and Play) trial: a randomized controlled trial of a primary care intervention for childhood overweight/mild obesity

OBJECTIVES

To reduce gain in body mass index (BMI) in overweight/mildly obese children in the primary care setting.

DESIGN

Randomized controlled trial (RCT) nested within a baseline cross-sectional BMI survey.

SETTING

Twenty nine general practices, Melbourne, Australia.

PARTICIPANTS

(1) BMI survey: 2112 children visiting their general practitioner (GP) April-December 2002; (2) RCT: individually randomized overweight/mildly obese (BMI z-score <3.0) children aged 5 years 0 months-9 years 11 months (82 intervention, 81 control).

INTERVENTION

Four standard GP consultations over 12 weeks, targeting change in nutrition, physical activity and sedentary behaviour, supported by purpose-designed family materials.

MAIN OUTCOME MEASURES

Primary: BMI at 9 and 15 months post-randomization. Secondary: Parent-reported child nutrition, physical activity and health status; child-reported health status, body satisfaction and appearance/self-worth.

RESULTS

Attrition was 10%. The adjusted mean difference (intervention-control) in BMI was -0.2 kg/m(2) (95% CI: -0.6 to 0.1; P=0.25) at 9 months and -0.0 kg/m(2) (95% CI: -0.5 to 0.5; P=1.00) at 15 months. There was a relative improvement in nutrition scores in the intervention arm at both 9 and 15 months. There was weak evidence of an increase in daily physical activity in the intervention arm. Health status and body image were similar in the trial arms.

CONCLUSIONS

This intervention did not result in a sustained BMI reduction, despite the improvement in parent-reported nutrition. Brief individualized solution-focused approaches may not be an effective approach to childhood overweight. Alternatively, this intervention may not have been intensive enough or the GP training may have been insufficient; however, increasing either would have significant cost and resource implications at a population level.

A proposed protocol for the development of a register of trials of weight management of childhood overweight and obesity

INTRODUCTION

Currently, there is no international co-ordinated approach to research into childhood obesity. This is despite much research activity in this area and the universality of the condition.

METHOD

This proposal involves the development of an international register of randomized controlled trials of weight management in overweight and obese children. The primary purpose of the register will be to generate and perform important, focussed prospective meta-analysis of data from trials using the conventional weight management strategies. Prospective meta-analysis is an emerging methodology and has some methodological advantages over retrospective meta-analysis.

PROPOSAL

The fundamental initial tasks will be to create scientific interest in the proposal, to identify and co-ordinate Management and Advisory Committees with international membership, to determine and define inclusion and exclusion criteria for trial registration, to define the questions that need to be addressed by prospective meta-analysis and finally to engage investigators to register.

Soft drink consumption and excess weight gain in Australian school students: results from the Nepean study

We studied the relation between soft drink/cordial (a sweet, flavoured, concentrated syrup that is mixed with water to taste), fruit juice/drink and milk consumption in mid-childhood, and body mass index (BMI) status in early adolescence in a contemporary Australian cohort. In 1996/7, 268 children (136 males) were recruited from western Sydney at baseline (mean+/-s.d.: 7.7+/-0.6 years), and at follow-up 5 years later (13.0+/-0.2 years). Height and weight were measured at both time periods and overweight and obesity defined using the International Obesity TaskForce criteria. Beverage consumption was calculated from a 3-day food record at baseline. Median carbohydrate intake from soft drink/cordial was 10 g higher (P=0.002) per day in children who were overweight/obese at follow-up compared to those who had an acceptable BMI at both baseline and follow-up. Intakes of soft drink/cordial in mid-childhood, but not fruit juice/fruit drink and milk, were associated with excess weight gain in early adolescence.

Obesity in children and adolescents with acquired brain injury

OBJECTIVES

To measure the prevalence of obesity and to assess associated clinical factors in children and adolescents with acquired brain injury (ABI).

STUDY DESIGN

This cross-sectional study included 88 subjects aged between 2.4-17.7 years attending the Brain Injury Clinic at a tertiary paediatric hospital. Body mass index (BMI) and BMI z-scores were calculated. Obesity and overweight were defined using the International Obesity Taskforce cut-points. Associations were examined between BMI z-scores and the following: ABI severity, mobility level, duration from injury and presence of radiological injury.

RESULTS

The prevalence of obesity in this population (obese = 15%) was higher than those in Australian children and adolescents (1995 National Nutrition Survey) while the prevalence of overweight (19.3%) was comparable. There was a linear trend for the participants to have a higher BMI z-score with increasing level of mobility (F = 6.91, df 1.70, p = 0.011).

CONCLUSION

There is no data about obesity in children and adolescents with ABI. The study with limited statistical power suggests that obesity is prevalent in this population and increases with increasing level of mobility. Further studies are required to address the issue of obesity and related complications in this population.

Policies to prevent childhood obesity in the European Union

The increasing prevalence of childhood obesity needs to be addressed. Without clear evidence to show which preventive interventions are most likely to work, a series of precautionary measures can be suggested. At a meeting of scientific experts organised by the International Obesity TaskForce and held at the European Congress on Obesity in May, 2004, a number of measures were proposed which follow the precautionary principle of promoting health while being unlikely to increase the risk of harm. The proposals are reported in the present paper.

Increasing central adiposity: the Nepean longitudinal study of young people aged 7–8 to 12–13 y

BACKGROUND

Estimates of the prevalence of overweight and obesity in young people are typically based on body mass index (BMI). However, BMI may not indicate the level of central adiposity. Waist circumference has therefore been recommended to identify young people at risk of morbidity associated with central adiposity.

OBJECTIVE

To investigate (a) change in total and central adiposity between 7-8 and 12-13 y (b) agreement between classifying young people as overweight or obese based on total adiposity and central adiposity, and (c) risk factors associated with the development of total and central adiposity.

DESIGN

Anthropometric measurements were taken on 342 children in 1996/97 and 5 y later. Risk factors examined included birth weight, physical activity, TV viewing, pubertal status, parental adiposity, diet and socio-economic status.

RESULTS

Between 7-8 and 12-13 y indices of central adiposity increased more than total adiposity; waist circumference z-score increased by (mean+/-s.d.) 0.74+/-0.92 and BMI z-score increased by 0.18+/-0.67. At 12-13 y there was moderate agreement between the two measures of adiposity (weighted kappa=0.64). However, waist circumference identified a greater number of young people as overweight or obese compared to BMI (41.2 vs 29.3%, P<0.001). Adiposity status at 7-8 y, maternal obesity, and pubertal stage were the strongest predictors of BMI status at 12-13 y. Risk factors associated with increased central adiposity were similar.

CONCLUSIONS

Overweight and obesity, as measured by waist circumference, is a bigger problem than is currently assessed by BMI. Targeting known risk factors for total adiposity may be an appropriate strategy for preventing increased central adiposity.

What are the effects of obesity in children on plantar pressure distributions?

OBJECTIVE

This study examined the effects of obesity on static and dynamic plantar pressure distributions displayed by children.

DESIGN

Field-based experimental data on body mass index (BMI) and plantar pressures were collected for 10 obese children and 10 nonobese controls.

SUBJECTS

In all, 10 obese (age 8.8+/-2.0 y, BMI 25.8+/-3.8 kg m(-2)) children matched to 10 nonobese children (age 8.9+/-2.1 y, BMI 16.8+/-2.0 kg m(-2)), for gender, age and height.

MEASUREMENTS

Height and weight were measured to calculate BMI. Right and left foot plantar pressures were obtained using an AT-4 emed pressure platform (Novel(gmbh), Munich) to calculate the peak force and pressure experienced under areas of each child's feet during static and dynamic conditions.

RESULTS

While standing, the obese children generated significantly higher forces over a larger foot area and experienced significantly higher plantar pressures compared to their nonobese counterparts (41.8+/-17.7; 30.1+/-12.0 N cm(-2), respectively; P<0.022). Similarly, while walking, the obese children generated significantly higher forces over all areas of their feet, except the toes. Despite distributing these higher forces over a significantly larger foot area when walking, the obese children experienced significantly higher plantar pressures in the midfoot (P<0.003) and under the second to fifth metatarsal heads (P<0.006) compared to the nonobese children.

CONCLUSIONS

It is postulated that obese children are at an increased risk of developing foot discomfort and/or foot pathologies due to increased plantar loads being borne by the small forefoot bones. Furthermore, continual bearing of excessive mass by children appears to flatten the medial midfoot region during walking. As the long-term consequences of these increased plantar loads are currently unknown, it is recommended that the effects of obesity on the structural and functional characteristics of obese children's feet be further investigated.

Outcomes of a nutrition audit in a tertiary paediatric hospital: implications for service improvement

OBJECTIVE

To examine the process of anthropometric assessment of nutritional status in a tertiary paediatric hospital, to identify the barriers and to make recommendations for service improvement.

METHODS

The accuracy of height and weight scales in wards was checked. Dietitians measured height and weight of a representative sample of 245 inpatients and checked whether these measurements had been recorded on bed charts. Patients were classified as overweight, obese or under-nourished. Diagnoses and procedures were obtained for each patient. Funding implications were modelled for inappropriate coding of nutritional status.

RESULTS

The barriers to nutritional assessment and management of nutritional comorbidities were: (i) inaccurate height scales in seven out of 12 wards; (ii) under-recording of height and weight on patient bed charts (73% height missing, 12% both height and weight missing); (iii) under-reporting of obesity and under-nutrition in medical notes (one of eight obese patients, and none of 28 undernourished patients, reported); and (iv) low referral rate of obese or under-nourished children to dietetic services (two of 42 overweight/obese patients referred, five of 28 undernourished patients referred). Funding simulation showed that if under-nourished patients were correctly diagnosed then the potential facility reimbursement would have increased by $A52 326.

CONCLUSIONS

Barriers to nutritional assessment can lead to failure to diagnose and treat both over- and under-nutrition, thereby affecting quality of patient care, and may have financial implications for hospitals. Suggestions for service improvement include provision of accurate equipment, adequate training of staff undertaking nutritional assessments and clear definitions of staff responsibilities in all aspects of the process.

Obesity and under-nutrition in a tertiary paediatric hospital

OBJECTIVE

(i) To determine the prevalence of over- and under-nutrition in both inpatients and outpatients in a tertiary paediatric hospital; (ii) to compare the prevalence of over-nutrition with that in the Australian community and (iii) to determine whether nutritional status has an impact on length of stay in hospital.

METHODS

Patients aged over 12 months were proportionately sampled from medical and surgical wards and outpatient clinics. Data were collected for 245 inpatients (54% male) and 272 outpatients (55% male). Children's height, weight and body mass index (kg/m2) were measured. Overweight, obesity and under-nutrition were defined according to international criteria. Prevalence of overweight and obesity was compared with that in the 1995 Australian National Nutrition Survey (NNS).

RESULTS

Similar proportions of inpatients and outpatients were underweight (6%) and wasted (4%). The prevalence of overweight and obesity in inpatients (22%) was similar to the NNS but was significantly higher in outpatients (32%, P < 0.0001). In a regression model to predict inpatient length of stay, nutritional status (P = 0.004) and the interaction between age and nutritional status (P = 0.009) were significant predictors. For over-nourished inpatients, length of stay increased significantly with age. For normally nourished and under-nourished inpatients, length of stay was relatively constant, regardless of age.

CONCLUSIONS

There is a high prevalence of over-nutrition in paediatric patients, and increased length of stay for older over-nourished inpatients. These issues need to be addressed in terms of opportunities for intervention and impact on hospital resources.

Food, activity and family—environmental vs biochemical predictors of weight gain in children

OBJECTIVE

To identify whether measures of energy intake and expenditure predict excessive weight gain over time in children and to describe how these measures relate to similar measures in parents.

DESIGN

Prospective, descriptive study over 12 months with no intervention.

SETTING

University teaching hospital.

SUBJECTS

Children aged between 6.0 and 9.0 y. Recruitment was through advertisement. A total of 59 children (30 F), 41 mothers and 29 fathers. In all, 41 (69%) of the children were reviewed at 12 months (20 F).

RESULTS

No significant correlations were identified between body mass index (BMI) z-score change in children over 12 months for any dietary variable or for any measures of energy expenditure, including hours of television viewing or percent time spent in low-, moderate- or high-intensity activity. The BMI z-score change over 12 months was significantly correlated with LDL cholesterol and Apo B/ApoA-1 ratio, independent of percent body fat (r=0.45, P=0.01; r=0.37, P=0.03). A significant positive correlation was found for mothers and girls for percent time in moderate to high activity (r=0.44, P=0.03) and between fathers and children for percent time spent in low activity (r=0.43, P=0.005).

CONCLUSIONS

The study has been unable to identify environmental predictors that indicate propensity to faster weight gain over time in this cohort of children, but has extended the evidence on lifestyle-influenced biochemical predictors that do. An overall lack of vigorous activity in this age group, and correlations between parental and child activity and inactivity have been identified.

The use of body mass index to predict body composition in children

BACKGROUND

Simple anthropometric indices of body composition have particular appeal for use in children, and as such body mass index (BMI) has been used to predict percentage body fat in a number of studies.

AIM

To evaluate the relationship between BMI and percentage body fat (%body fat) and a proposed, more appropriate relationship between BMI and fat mass/height(2) in a cohort of young children.

SUBJECTS AND METHODS

Cross-sectional study of 109 children aged between 6 and 10 years residing in either Sydney or Brisbane, Australia. Weight and height were measured using standard methods. Body composition was measured using a stable isotope method to firstly determine total body water and subsequently fat free mass.

RESULTS

The correlation between BMI and fat mass/height(2) was markedly greater than that between BMI and percentage body fat. In the entire group of children the R(2) (x100%) value for the relationship between BMI and fat mass/height(2) was 73.3% compared with 46.5% for the relationship between BMI and percentage body fat.

CONCLUSIONS

We have shown that the use of BMI to predict fat mass/height(2), and consequently percentage body fat, is superior to the use of BMI to predict percentage body fat based directly upon the R(2) values of the above analysis.

Low-density lipoprotein subclasses in children under 10 years of age

OBJECTIVE

To examine the prevalence of small dense low density lipoprotein (LDL) in a cohort of children under 10 years of age and to investigate the relationship to other biochemical variables and to measures of fatness. A preponderance of small dense LDL (pattern B), is associated with obesity, abdominal fat accumulation, insulin resistance and risk of heart disease in adults.

METHODOLOGY

LDL peak particle diameter (PPD) was determined by gel electrophoresis in 53 children under 10 years of age and in 65 of their parents: apoproteins A1 and B were determined by turbidimetry. Anthropometric variables, basic lipid profiles, insulin and leptin had been determined previously. Differences between patterns A (large light particles > 25.5 nm diameter) and B were examined by t-test, Chi-square, or Mann-Whitney test. Relationships between the variables were reported as Pearson correlation coefficients.

RESULTS

Pattern B (PPD of < or = 25.5 nm) prevalence was 7.5% in children and 11% in parents (17% in men and 5% in women). Most of the children (86%) who had PPD < or = 26.0 nm also had parents with PPD in this range. A strong association was found between children's and mother's PPD (r=0.60, P < 0.001), but this was somewhat less with fathers (r=0.40, P=0.02). Children in the lowest tertile of PPD had a tendency towards a higher body mass index, waist, fat mass and insulin.

CONCLUSIONS

The prevalence of small dense LDL is lower in children under 10 years of age than in their parents; fathers had a higher prevalence of pattern B than mothers and there is some evidence of a familial effect in the inheritance of pattern B.

Abdominal fat and birth size in healthy prepubertal children

BACKGROUND

Studies examining the foetal origins hypothesis suggest that small birth size may be a marker of foetal adaptations that programme future propensity to adult disease. We explore the hypothesis that birth size may relate to fat distribution in childhood and that fat distribution may be a link between birth size and adult disease.

OBJECTIVE

To investigate the relationship between birth size and abdominal fat, blood pressure, lipids, insulin and insulin:glucose ratio in prepubertal children.

DESIGN

Cross-sectional study, based on a birth cohort of consecutive full-term births.

SUBJECTS

Two hundred and fifty-five (137 females) healthy, 7- and 8-y-old children.

MEASUREMENTS

Body composition and abdominal fat was measured by dual energy X-ray absorptiometry. Lipid, glucose and insulin profiles were measured after an overnight fast and an automated BP monitor was used for blood pressure measurements.

RESULTS

There was a negative association between abdominal fat and birth weight s.d. score across a range of normal birth weights (beta=-0.18; 95% CI=-0.31 to -0.04, P=0.009) and a positive association with weight s.d. score at 7/8 y (beta=0.35; 95% CI=0.24 to 0.46, P<0.001). Children who were born with the lowest weight s.d. score and had the greatest weight s.d. score at 7/8 y had significantly more (P<0.001) abdominal fat, as a percentage of total fat (6.53+/-1.3%) than those who had the highest birth weight s.d. score and the lowest weight s.d. score at 7/8 y (4.14+/-0.5%). Similar results were seen if head circumference, but not ponderal index, was used as an indicator of birth size. Increased abdominal fat was associated with higher total cholesterol:HDL cholesterol, higher triglyceride concentration and increased diastolic blood pressure.

CONCLUSIONS

Birth weight independently predicted abdominal fat. Children with the highest amount of abdominal fat were those who tended to be born lighter and gained weight centiles. Increased abdominal fat was associated with precursor risk factors for ischaemic heart disease.

Comparison of total energy expenditure and energy intake in children aged 6-9 y

BACKGROUND

The accurate measurement of food intake in children is important for assessing nutritional status.

OBJECTIVE

We sought to both compare measurements of energy intake (EI) from diet records and of total energy expenditure (TEE) by the doubly labeled water (DLW) method and to investigate misreporting of EI.

DESIGN

Forty-seven children (22 boys and 25 girls) aged 7.4 +/- 0.8 y ( +/- SD) were recruited from 25 schools in western Sydney. TEE was measured by DLW over 10 d and EI by use of 3-d food records. Misreporting was defined as [(EI - TEE)/TEE] x 100%.

RESULTS

Girls had a higher (P = 0.02) percentage of body fat (28.2 +/- 7.0%) than did boys (22.9 +/- 8.0%); otherwise there were no differences among sex. Although mean (+/-SD) values for EI (7514 +/- 1260 kJ/d) and TEE (7396 +/- 1281 kJ/d) were not significantly different, there was no significant correlation between EI and TEE. EI and TEE were 9% and 11% lower, respectively, than current World Health Organization recommendations for EI. The relative bias (mean difference, EI - TEE) was low at 118 kJ/d, but the limits of agreement (bias +/- 2 SD of the difference) were wide at 118 +/- 3345 kJ/d. Although the mean percentage of misreporting was low (4 +/- 23%), the high SD indicates large intraindividual differences between EI and TEE. The most significant predictor of misreporting was dietary fat intake (r(2) = 0.45, P < 0.0001). Misreporting was not associated with sex or body composition.

CONCLUSIONS

In this age group, reported EI is not representative of TEE at the individual level. However, at the population level, 3-d food records may be used for surveys of EI by 6-9-y-old children.

Total energy expenditure, body fatness, and physical activity in children aged 6-9 y

BACKGROUND

The recent worldwide increase in the prevalence of childhood obesity may be due in part to a decrease in children's physical activity levels.

OBJECTIVE

The current study of children in the years just before puberty aimed to 1) measure total energy expenditure (TEE) by use of the doubly labeled water (DLW) method, 2) determine the proportion of TEE related to physical activity, 3) investigate the relations between measures of physical activity and body fatness, and 4) investigate possible sex differences in these relations.

DESIGN

The DLW technique was used to measure TEE over 10 d in 106 healthy children (52 boys) aged 7.8 +/- 0.9 y (x +/- SD). Fat-free mass, and hence fat mass, was derived from the (18)O dilution space. Resting energy expenditure (REE) was calculated with use of the Schofield equations. Physical activity level was calculated as TEE/REE.

RESULTS

Mean TEE in both boys (7871 +/- 1135 kJ/d) and girls (7512 +/- 1195 kJ/d) was significantly different (P < 0.0001) from FAO/WHO/UNU recommendations (13% and 9% lower, respectively). There was no significant difference in physical activity level between boys (1.69 +/- 0.22) and girls (1.71 +/- 0.23). In boys but not girls, physical activity level was inversely correlated with BMI (r = -0.37, P < 0.01), fat mass (r = -0.46, P < 0.005), and percentage of body fat (r = -0.50, P < 0.0001).

CONCLUSIONS

In boys but not girls, percentage of body fat is inversely associated with physical activity level. Physical activity is one factor contributing to body fatness in boys, but additional factors may influence the size of the fat stores in girls.

Does obesity influence foot structure and plantar pressure patterns in prepubescent children?

OBJECTIVE

This study examined the effects of obesity on plantar pressure distributions in prepubescent children.

DESIGN

Field-based, experimental data on BMI (body mass index), foot structure and plantar pressures were collected for 13 consenting obese children and 13 non-obese controls.

SUBJECTS

Thirteen obese (age 8.1+/-1.2 y; BMI 25.5+/-2.9 kg/m(2)) and 13 non-obese (age 8.4+/-0.9 y; BMI 16.9+/-1.2 kg/m(2)) prepubescent children, matched to the obese children for gender, age and height.

MEASUREMENTS

Height and weight were measured to calculate BMI. Static weight-bearing footprints for the right and left foot of each subject were recorded using a pedograph to calculate the footprint angle and the Chippaux-Smirak index as representative measures of the surface area of the foot in contact with the ground. Right and left foot plantar pressures were then obtained using a mini-emed(R) pressure platform to calculate the force and pressure experienced under each child's foot during static and dynamic loaded and unloaded conditions.

RESULTS

Obese subjects displayed significantly lower footprint angle (t=4.107; P=<0.001) values and higher Chippaux-Smirak index values (t=-6.176; P=<0.001) compared to their non-obese counterparts. These structural foot changes were associated with differences in plantar pressures between the two subject groups. That is, although rearfoot dynamic forces generated by the obese subjects were significantly higher than those generated by the non-obese subjects, these forces were experienced over significantly higher mean peak areas of contact with the mini-emed(R) system. Therefore, rearfoot pressures experienced by the two subject groups did not differ. However, the mean peak dynamic forefoot pressures generated by the obese subjects (39.3+/-15.7 N.cm(-2); q=3.969) were significantly higher than those generated by the non-obese subjects (32.3+/-9.2 N.cm(-2)).

CONCLUSIONS

It is postulated that foot discomfort-associated structural changes and increased forefoot plantar pressures in the obese foot may hinder obese children from participating in physical activity and therefore warrants immediate further investigation.

Preliminary report: skeletal muscle cell lipid and oxygen supply

In a group of 12 normal-weight, normotensive, nondiabetic adult females, the intramyocellular lipid (IMCL) to creatine ratio of the soleus muscle was determined using localized (1)H-magnetic resonance spectroscopy ((1)H-MRS) and related to skeletal muscle blood (and oxygen) supply (as assessed by near infrared spectroscopy [NIRS] of the forearm). A significant positive association was found between IMCL content and reoxygenation rate of forearm muscle hemoglobin (Hb) after 1 minute of ischemic exercise (r = .70, P = .01). The relative efficiency of skeletal muscle oxygen supply may be a determining factor of IMCL content in skeletal muscle.

Fracture of the first rib as a consequence of pertussis infection

We report the first described case of a first rib fracture secondary to pertussis infection. An 11-year-old boy presented with sudden onset of severe right-sided pleuritic chest pain on a background of a 6 week history of a coughing illness and considerable weight loss. Pertussis was clinically suspected and proven on serology. A cause for the severe pain was initially difficult to confirm, causing some concern regarding possible underlying pathology, but was later demonstrated to be due to a first rib fracture. The anatomy of the first rib, and the biomechanical forces placed upon it that are exacerbated during a coughing illness are described.

Altered energy metabolism in anorexia nervosa

Optimal nutritional rehabilitation of anorexia nervosa requires more information concerning actual energy and substrate requirements. To this end, indirect calorimetry was performed in female patients (n=34, age 20.9+/-1.2 yr, body mass index [BMI] 15.6+/-0.2 kg/m(2); mean+/-SEM) soon after commencement of refeeding and at the time of discharge from hospital (n=18, BMI 19.0+/-0.3 kg/m(2)). Healthy female controls (n=18, age 24.6+/-1.3 yr, BMI 21.6+/-0.6 kg/m(2)) were also tested. Resting energy expenditure (REE) and respiratory quotient (RQ) were measured in the fasting state, followed by diet-induced thermogenesis (DIT) and RQ over a 4 h period following a 100 g oral glucose load. Compared with post-refeeding patients and controls, pre-refeeding patients had a high basal RQ and a low REE, with a paradoxically higher DIT (13.2+/-0.9% of REE vs. 8.3+/-1.2% and 8.6+/-0.9% in post-refeeding patients and controls, respectively). RQ values in pre-refeeding patients exceeded unity following the glucose load, probably reflecting net lipogenesis, whereas in the post-refeeding patients, post-glucose RQ was similar to that of controls, suggesting premature curtailment of lipogenesis. These data demonstrate energy wasting in emaciated patients with anorexia nervosa. Biological repair processes could account for disproportionate energy loss early in refeeding and there may be some later impediment to full restoration of fat stores.