Michelle Jackson

Foods prepared outside the home: association with selected nutrients and body mass index in adult Australians

OBJECTIVE To determine the proportion of energy from foods prepared outside the home (FPOH) and the relationships with energy and nutrient intakes and body mass index (BMI). DESIGN A nutrition survey of a representative sample of the Australian population aged 18 years and over Measure used was a 24-hour dietary recall. Underreporters (energy intake/estimated basal metabolic rate (EI/BMR) <0.9) were excluded from analysis. Daily energy and selected nutrient intakes were calculated using a 1996 nutrient composition database for all foods/beverages during the 24-hour period. RESULTS On average FPOH contributed a significant 13% to total energy intake. About a third of the sample had consumed FPOH in the last 24 hours and on average this group consumed a third of their total energy as FPOH. The relative contributions of fat (for men and women) and alcohol (for women) were significantly higher for those in the top tertile of FPOH consumers. The intakes of fibre and selected micronutrients (calcium, iron, zinc, folate and vitamin C) were significantly lower in this group. After adjustment for age and income no relationship between FPOH and BMI was observed. CONCLUSIONS FPOH make a significant contribution to the energy intake of a third of the Australian population. FPOH contribute to poor nutritional intakes. Altering the supply of FPOH may be an effective means of improving diets at a population level.

Family physical activity and sedentary environments and weight change in children

OBJECTIVE To examine associations between family physical activity and sedentary environment and changes in body mass index (BMI) z-scores among 10-12-year-old children over three years. METHOD Design. Longitudinal (three-year follow-up). Subjects. In total, 152 boys and 192 girls aged 10-12 years at baseline. MEASUREMENTS Measured height and weight at baseline and follow-up (weight status, BMI z-scores); aspects of the family physical activity and sedentary environment (parental and sibling modelling, reinforcement, social support, family-related barriers, rules/restrictions, home physical environment) measured with a questionnaire completed by parents at baseline. RESULTS At baseline, 29.6% of boys and 21.9% of girls were overweight or obese, and mean (standard deviation, SD) BMI z-scores were 0.44 (0.99) and 0.28 (0.89), respectively. There was a significant change in BMI z-score among girls (mean change = 0.19, SD = 0.55, p < 0.001), but not boys. Among boys, the number of items at home able to be used for sedentary behaviour (B = 0.11, p = 0.037) was associated with relatively greater increases in BMI z-score. Among girls, sibling engagement in physical activity at least three times/wk (B = -0.17, p = 0.010) and the number of physical activity equipment items at home (B = -0.05, p = 0.018) were associated with relatively greater decreases in BMI z-score. CONCLUSION Sibling physical activity and environmental stimuli for sedentary behaviours and physical activity within the home may be important targets for prevention of weight gain during the transition from childhood to adolescence.

Associations between family circumstance and weight status of Australian children

OBJECTIVE To examine associations between weight status and multiple indicators of family circumstance in Australian elementary school children. METHODS Data were combined from the 2001 Childrens Leisure Activities Study (CLAS Study) and 2002/3 Health, Eating and Play Study (HEAP Study), involving 2520 children in Grades Prep (mean age 6 years) and 5-6 (mean age 11 years) in Melbourne, Australia. Childrens body mass index (BMI) was calculated from measured height and weight. Weight status (non-overweight or overweight) was determined according to International Obesity Taskforce cut-off points and BMI was transformed to z-scores based on the 2000 US growth chart data. Parents reported family circumstance (number of parents in the home, marital status, presence of siblings, parental education, parental employment status, parental work hours [HEAP Study only]) and parental BMI. Regression analyses were conducted for the sample overall and separately for young girls, young boys, older girls and older boys. RESULTS Children in single-parent homes, those without siblings, and those with less educated mothers and fathers tended to have higher z-BMIs (p=0.002, p=0.003, p<0.001 and p<0.001, respectively) and were more likely to be overweight (p=0.003, p<0.001, p<0.001 and p=0.02, respectively). Associations were stronger for older children. Parental employment and work hours were not consistently associated with child weight status. The multivariable models did not demonstrate a cumulative explanatory effect (R(2)=0.02), except when maternal BMI was included (R(2)=0.07). CONCLUSIONS Individual measures of family circumstance were differentially associated with child weight status and appeared to be largely independent of other measures of family circumstance. Childhood overweight interventions may need to be tailored based on the age, gender, maternal BMI and family circumstances of the target group.

Beliefs about the causes of weight change in the Australian population

OBJECTIVE: To describe self-reported weight change and beliefs about the causes of weight change and to examine whether these vary by sex and weight status.DESIGN: This cross-sectional population study examined data from the 1995 Australian National Health and Nutrition Surveys.SUBJECTS: A total of 10 624 randomly-selected adults provided data.MEASURES: Objectively measured height and weight, perceptions of current weight status, self-reported weight change over the past year, and reasons for weight change.RESULTS: Thirty-five percent of participants reported a weight gain in the last 12 months, with females, and those already overweight more likely to report a recent increase in weight. Approximately one in five participants reported a recent weight loss. Those who had recently gained weight were more likely to perceive themselves as overweight regardless of actual weight status. Commonly reported reasons for weight gain included a change in physical activity level (52% males and 35% females) and a change in the amount of food/drink consumed (30% males, 27% females). Similar reasons were given for weight loss.CONCLUSIONS: Findings of widespread reported weight gain, particularly among those already overweight, suggest Australias obesity epidemic may be worsening. Strategies are urgently required to better inform individuals about the factors impacting on their weight in order to prevent further weight gain.

Are Parental Concerns About Children's Inactivity Warranted, and Are They Associated With a Supportive Home Environment?

This paper explores parental concern about childrens activity levels and whether parents who are concerned about their childs activity provide a supportive environment. A sample of 615 parents of 5–6-year-old children and 947 parents of 10–12-year-old children completed a questionnaire. Just over 50% of parents reported they were concerned their child was not getting enough activity. Children of concerned parents were less active than those whose parents were not concerned. These findings suggest that parents who are concerned about their childs physical activity levels provided a less supportive environment for physical activity than parents who are not concerned. The challenge for public health will be to harness parental concerns and translate them into action.