Obesity in pre-school children: Issues and challenges for community based child health nurses

Childhood obesity is becoming a topical issue in both the health literature and the popular media and increasingly child health nurses are observing preschool children who appear to be disproportionately heavy for their height when plotted on standardised growth charts. In this paper literature related to childhood obesity in New Zealand and internationally is explored to identify current issues, and the implications of these issues for nurses in community based child health practice are discussed. Themes that emerged from the literature relate to the measurement of obesity, links between childhood and adult obesity and issues for families. A theme in the literature around maternal perception was of particular interest. Studies that investigated maternal perceptions of childhood obesity found that mothers identified their child as being overweight or obese only when it imposed limitations on physical activity or when the children were teased rather than by referring to individual growth graphs. The implications for nursing in the area of child health practice is discussed as nurses working in this area need an understanding of the complex and often emotive issues surrounding childhood obesity and an awareness of the reality of people's lives when devising health promotion strategies.

Validity of BMI as a measure of obesity in Australian white Caucasian and Australian Sri lankan children

Background: Body mass index ( BMI) is used to diagnose obesity. However, its ability to predict the percentage fat mass (% FM) reliably is doubtful. Therefore validity of BMI as a diagnostic tool of obesity is questioned. Aim: This study is focused on determining the ability of BMI- based cut- off values in diagnosing obesity among Australian children of white Caucasian and Sri Lankan origin. Subjects and methods: Height and weight was measured and BMI ( W/H-2) calculated. Total body water was determined by deuterium dilution technique and fat free mass and hence fat mass derived using age- and gender- specific constants. A % FM of 30% for girls and 20% for boys was considered as the criterion cut- off level for obesity. BMI- based obesity cut- offs described by the International Obesity Task Force ( IOTF), CDC/ NCHS centile charts and BMI- Z were validated against the criterion method. Results: There were 96 white Caucasian and 42 Sri Lankan children. Of the white Caucasians, 19 ( 36%) girls and 29 ( 66%) boys, and of the Sri Lankans 7 ( 46%) girls and 16 ( 63%) boys, were obese based on % FM. The FM and BMI were closely associated in both Caucasians ( r = 0.81, P < 0.001) and Sri Lankans ( r = 0.92, P< 0.001). Percentage FM and BMI also had a lower but significant association. Obesity cut- off values recommended by IOTF failed to detect a single case of obesity in either group. However, NCHS and BMI- Z cut- offs detected cases of obesity with low sensitivity. Conclusions: BMI is a poor indicator of percentage fat and the commonly used cut- off values were not sensitive enough to detect cases of childhood obesity in this study. In order to improve the diagnosis of obesity, either BMI cut- off values should be revised to increase the sensitivity or the possibility of using other indirect methods of estimating the % FM should be explored.

Breastfeeding and obesity at 14 years: A cohort study

Aim: To determine the influence of breastfeeding on overweight and obesity in early adolescence. Methods: Data about breastfeeding duration, BMI of children at 14 years, and confounding variables, were collected from an ongoing longitudinal study of a birth cohort of 7776 children in Brisbane. Prevalence of overweight and obesity at 14 years was assessed according to duration of breastfeeding, with logistic regression being used to adjust for the influence of confounders. Results: Data were available for 3698 children, and those not included were significantly different in age, educational level, income, race, birthweight, and small-for-gestational-age status. Breastfeeding for longer than six months was protective of obesity (OR 0.6, 95% CI 0.4, 0.96) though not of overweight. When confounding variables were considered the effect size diminished and lost statistical significance OR 0.8 (95% CI 0.5, 1.3). Breastfeeding for less than 6 months had no effect on either obesity or overweight though a trend was found for increased prevalence of overweight at 14 years with shorter periods of breastfeeding. Conclusion: This investigation contributes to the gathering body of evidence that breastfeeding for longer than 6 months has a modest protective effect against obesity in adolescence.

The prevalence and impact of overweight and obesity in an Australian obstetric population

Objective: To assess the prevalence and impact of overweight and obesity in an Australian obstetric population. Design, setting and participants: The Mater Mother's Hospital (MMH), South Brisbane, is an urban tertiary referral maternity hospital. We reviewed data for the 18401 women who were booked for antenatal care at the MMH, delivered between January 1998 and December 2002, and had a singleton pregnancy. Of those women, 14 230 had an estimated pre-pregnancy body mass index (BMI) noted in their record; 2978 women with BMI 40 kg/m(2)). Main outcome measures: Prevalence of overweight and obesity in an obstetric population; maternal, peripartum and neonatal outcomes associated with raised BMI. Results: Of the 14230 women, 6443 (45%) were of normal weight, and 4809 (34%) were overweight, obese or morbidly obese. Overweight, obese and morbidly obese women were at increased risk of adverse outcomes (figures represent adjusted odds ratio [AOR] [95% Cl]): hypertensive disorders of pregnancy (overweight 1.74 [1.45-2.15], obese 3.00 [2.40-3.74], morbidly obese 4.87 [3.27-7.24]); gestational diabetes (overweight 1.78 [1.25-2.52], obese 2.95 [2.05-4.25], morbidly obese 7.44 [4.42-12.54]); hospital admission longer than 5 days (overweight 1.36 [1.13-1.63], obese 1.49 [1.21-1.86], morbidly obese 3.18 [2.19-4.61]); and caesarean section (overweight 1.50 [1.36-1.66], obese 2.02 [1.79-2.29], morbidly obese 2.54 [1.94-3.321). Neonates born to obese and morbidly obese women had an increased risk of birth defects (obese 1.58 (1.02-2.46], morbidly obese 3.41 [1.67-6.94]); and hypoglycaemia (obese 2.57 [1.39-4.78], morbidly obese 7.14 [3.04-16.74]). Neonates born to morbidly obese women were at increased risk of admission to intensive care (2.77 [1.81-4.25]); premature delivery (< 34 weeks' gestation) (2.13 [1.13-4.01]); and jaundice (1.44 [1.09-1.89]). Conclusions: Overweight and obesity are common in pregnant women. Increasing BMI is associated with maternal and neonatal outcomes that may increase the costs of obstetric care. To assist in planning health service delivery, we believe that BMI should be routinely recorded on perinatal data collection sheets