A cross-sectional study examining the pattern of childhood obesity in Leeds: affluence is not protective.

BACKGROUND: The aim of this paper was to investigate variations in childhood obesity globally and spatially at the micro-level across Leeds. METHODS: Body mass index data from three sources were used. Children were aged 3-13 years. Obesity was defined as above the 98th centile (British reference dataset). The data were analysed by age group and gender, then tested for significant micro-level hot spots of childhood obesity using a spatial scan statistic and a two-level multilevel model. RESULTS: Older children (13 years) were 2.5 times (95% CI 2.1 to 3.1) more likely to be obese than younger children (3 years). Childhood obesity was significantly associated with deprived and affluent areas. 'Blue collar communities,' 'Constrained by circumstances' and 'Multicultural' had significantly higher (relative risk (RR): 1.1, 1.2, 1.2; 95% CI 1.0 to 1.2, 1.1 to 1.2, 1.1 to 1.3, respectively) obesity levels, and 'Typical traits' and 'Prospering suburbs' had significantly lower (RR: 0.9, 0.8; 95% CI 0.8 to 1.0, 0.7 to 0.9, respectively) obesity levels. In the unadjusted model, obesity 'hot spots' were found in deprived (RR 1.5) and affluent (RR 6.1) areas. After adjusting for demographic covariates, hot spots were found only in affluent areas (RR 1.6 to 1.9), and cold spots in affluent (RR 1.3 to 4.4) and deprived (RR up to 1.1) areas. CONCLUSION: These results suggest there is either a spread of obesity across socio-economic groups and/or something special about the high-/low-prevalence areas that affects the likelihood of obesity. The microlevel spatial analyses displayed the variations in obesity across Leeds thoroughly, identifying high-risk populations.

The neighbourhood matters: studying exposures relevant to childhood obesity and the policy implications in Leeds, UK.

BACKGROUND: Reducing childhood obesity is a key UK government target. Obesogenic environments are one of the major explanations for the rising prevalence and thus a constructive focus for preventive strategies. Spatial analysis techniques are used to provide more information about obesity at the neighbourhood level in order to help to shape local obesity-prevention policies. METHODS: Childhood obesity was defined by body mass index, using cross-sectional height and weight data for children aged 3-13 years (obesity>98th centile; British reference dataset). Relationships between childhood obesity and 12 simulated obesogenic variables were assessed using geographically weighted regression. These results were applied to three wards with different socio-economic backgrounds, tailoring local obesity-prevention policy. RESULTS: The spatial distribution of childhood obesity varied, with high prevalence in deprived and affluent areas. Key local covariates strongly associated with childhood obesity differed: in the affluent ward, they were perceived neighbourhood safety and fruit and vegetable consumption; in the deprived ward, expenditure on food, purchasing school meals, multiple television ownership and internet access; in all wards, perceived access to supermarkets and leisure facilities. Accordingly, different interventions/strategies may be more appropriate/effective in different areas. CONCLUSIONS: These analyses identify the covariates with the strongest local relationships with obesity and suggest how policy can be tailored to the specific needs of each micro-area: solutions need to be tailored to the locality to be most effective. This paper demonstrates the importance of small-area analysis in order to provide health planners with detailed information that may help them to prioritise interventions for maximum benefit.

Does the school fruit and vegetable scheme improve children's diet? A non-randomised controlled trial.

OBJECTIVE: Evaluation of the impact on diet of the school fruit and vegetable scheme (SFVS). DESIGN: Non-randomised controlled trial. SETTING: Infant and primary schools in the north of England. PARTICIPANTS: 3,703 children aged four to six years (reception, year 1, and year 2). INTERVENTION: One portion of fruit or vegetable provided per child on each school day between February and December 2004. MAIN OUTCOME MEASURES: Fruit and vegetables consumed and intake of nutrients. RESULTS: The SFVS was associated with an increase in fruit intake across reception and year 1 pupils of 0.4 portions (95% confidence interval, 0.2 to 0.5) and 0.6 portions (0.4 to 0.9), respectively, at three months, which fell to 0.2 (0.1 to 0.4) and 0.3 (0.1 to 0.6) at seven months. In year 2 it was associated with an increase of 0.5 portions (0.2 to 0.7) of fruit at three months, which fell to baseline values at seven months when these children were no longer eligible for the scheme. Overall, at seven months there were no changes in vegetable consumption, no associations between the SFVS and energy, fat, or salt intake, and small changes in carotene and vitamin C intake. CONCLUSIONS: The SFVS promoted an increase in fruit intake after three months. At seven months the effect remained significant but reduced, and it returned to baseline in year 2 when pupils were no longer part of the scheme. There was a small impact on the intake of some nutrients across the children surveyed.

Use of itemized Till receipts to adjust for correlated dietary measurement error.

Recent studies suggest that measurement error in food frequency questionnaires includes a person-specific component correlated with that of other self-reported dietary assessments. Use of biomarkers has been recommended to adequately calibrate dietary assessment tools for unbiased estimation of associations between diet and disease. Data on biomarkers of intake are often collected only in small subsamples, because collection of biomarker data can be expensive and inconvenient for participants. In this paper, the authors propose a novel approach using itemized household grocery till receipts to calibrate dietary assessment. Till receipts are not self-recorded and the data obtained from them are not subject to person-specific bias, but the data need to be supported by self-completed diaries for foods eaten away from home. Till receipts may also prove cheaper to collect in larger samples. The authors discuss the many methodological challenges of using household-level data and discuss how till receipts might be used in practice, with or without the use of biomarkers.

Use of supermarket receipts to estimate energy and fat content of food purchased by lean and overweight families.

The aim of this study was to compare the energy and fat content of food purchased for home consumption by households comprising mainly overweight individuals (OH), with those comprising mainly lean individuals (LH). 214 supermarket shoppers and their household were recruited from a Tesco supermarket in Leeds (UK). Households collected supermarket receipts and completed a shopping diary for 28-days, and each member of the household completed a 4-day food record. OH purchased food higher in fat (38% total energy from fat) than LH, (34.9%: p=0.001) and they purchased more energy and fat per adult equivalent, per day than LH (10.05 MJ compared to 9.15 MJ: p=0.01 and 103 g compared to 86 g:p=0.001). Households were 15% more likely to be classified as OH for each additional MJ of energy purchased per person, per day, after adjusting for number of children, household size, age, sex and social class. It was concluded that food purchasing behaviour may be linked to the prevalence of obesity in households who shop at supermarkets.

The use of supermarket till receipts to determine the fat and energy intake in a UK population.

OBJECTIVES: To validate the use of supermarket receipts as an index of fat and energy intake in a population that buys most of its food from supermarkets. DESIGN: Cross-sectional, prospective dietary survey - feasibility study. SETTING: Households situated within a 20-mile radius of a large (Tesco) supermarket in Leeds. SUBJECTS: Two hundred and fourteen households who spend >or=60% of their food purse in (Tesco and other) supermarkets. RESULTS: Mean daily household purchase of fat, energy and percentage energy from fat contained in food from supermarkets were 185 g, 19.2 MJ and 35.9%. Mean daily household intakes of fat and energy were 190 g and 20.7 MJ, and 35% of energy was derived from fat. Mean household size was 2.4 persons. The association between the amount of fat and energy purchased from supermarkets and the amount of fat and energy consumed by households was strong. 0.90 MJ (95% confidence interval (CI): 0.8-1.0) of energy were consumed for every 1 MJ purchased from supermarkets and 0.76 g (95% CI: 0.64-0.87) of fat were consumed for every 1 g of fat purchased. CONCLUSIONS: The results show a strong association between estimates of the intakes of fat and energy and percentage energy from fat using 4-day food diaries and 28 days of receipts, in populations who buy most of their food from supermarkets. They also show that the fat content of total food purchases from supermarkets is 35.9% energy from fat compared with 33% energy from fat recommended by the Department of Health. This preliminary research indicates the feasibility of and potential for utilising large quantities of readily available data generated from supermarket checkouts in dietary surveys.