Fast-food intake and perceived and objective measures of the local fast-food environment in adolescents.

OBJECTIVE: We examined associations between fast-food intake and perceived and objective fast-food outlet exposure. DESIGN: Information from the Health Behaviours in School-aged Children Study was linked to fast-food outlets in seventy-five school neighbourhoods. We used multivariate multilevel logistic regression analyses to examine associations between at least weekly fast-food intake and perceived and objective fast-food outlet measures. SUBJECTS: Data represent 4642 adolescents (aged 11-15 years) in Denmark. RESULTS: Boys reporting two or more fast-food outlets had 34% higher odds consuming fast food at least weekly. We detected higher odds of at least weekly fast-food intake among 15-year-old 9th graders (ORall=1.74; 95% CI 1.40, 2.18; ORboys=2.20; 95% CI 1.66, 2.91; ORgirls=1.41; 95% CI 1.03, 1.92), Danish speakers (ORall=2.32; 95% CI 1.68, 3.19; ORboys=2.58; 95% CI 1.69, 3.93; ORgirls=2.37; 95% CI 1.46, 3.84) and those travelling 15 min or less to school (ORall=1.21; 95% CI 1.00, 1.46; ORgirls=1.44; 95% CI 1.08, 1.93) compared with 11-year-old 5th graders, non-Danish speakers and those with longer travel times. Boys from middle- (OR=1.28; 95% CI 1.00, 1.65) and girls from low-income families (OR=1.46; 95% CI 1.05, 2.04) had higher odds of at least weekly fast-food intake compared with those from high-income backgrounds. Girls attending schools with canteens (OR=1.47; 95% CI 1.00, 2.15) had higher odds of at least weekly fast-food intake than girls at schools without canteens. CONCLUSIONS: The present study demonstrates that perceived food outlets may impact fast-food intake in boys while proximity impacts intake in girls. Public health planning could target food environments that emphasize a better understanding of how adolescents use local resources.

The correlation between supermarket size and national obesity prevalence.

BACKGROUND: Supermarkets provide healthy and affordable food options while simultaneously heavily promoting energy-dense, nutrient-poor foods and drinks. Store size may impact body weight via multiple mechanisms. Large stores encourage purchasing of more food in a single visit, and in larger packages. In addition they provide greater product choice (usually at lower prices) and allow greater exposure to foods of all types. These characteristics may promote purchasing and consumption. Our objective was to assess the relationship between supermarket size and obesity, which has rarely been assessed. RESULTS: Data on supermarket size (measured as total aisle length in metres) was from 170 stores in eight developed countries with Western-style diets. Data for national obesity prevalence was obtained from the UK National Obesity Observatory. We found a strong correlation between average store size and national obesity prevalence (r = 0.96). CONCLUSIONS: Explanations for the association between store size and national obesity prevalence may include larger and less frequent shopping trips and greater choice and exposure to foods in countries with larger stores. Large supermarkets may represent a food system that focuses on quantity ahead of quality and therefore may be an important and novel environmental indicator of a pattern of behaviour that encourages obesity.

Does the availability of snack foods in supermarkets vary internationally?

BACKGROUND: Cross-country differences in dietary behaviours and obesity rates have been previously reported. Consumption of energy-dense snack foods and soft drinks are implicated as contributing to weight gain, however little is known about how the availability of these items within supermarkets varies internationally. This study assessed variations in the display of snack foods and soft drinks within a sample of supermarkets across eight countries. METHODS: Within-store audits were used to evaluate and compare the availability of potato chips (crisps), chocolate, confectionery and soft drinks. Displays measured included shelf length and the proportion of checkouts and end-of-aisle displays containing these products. Audits were conducted in a convenience sample of 170 supermarkets across eight developed nations (Australia, Canada, Denmark, Netherlands, New Zealand, Sweden, United Kingdom (UK), and United States of America (US)). RESULTS: The mean total aisle length of snack foods (adjusted for store size) was greatest in supermarkets from the UK (56.4 m) and lowest in New Zealand (21.7 m). When assessed by individual item, the greatest aisle length devoted to chips, chocolate and confectionery was found in UK supermarkets while the greatest aisle length dedicated to soft drinks was in Australian supermarkets. Only stores from the Netherlands (41%) had less than 70% of checkouts featuring displays of snack foods or soft drinks. CONCLUSION: Whilst between-country variations were observed, overall results indicate high levels of snack food and soft drinks displays within supermarkets across the eight countries. Exposure to snack foods is largely unavoidable within supermarkets, increasing the likelihood of purchases and particularly those made impulsively.

Fruit and vegetable intake in adolescents: association with socioeconomic status and exposure to supermarkets and fast food outlets.

Background. We investigated differences in family social class associations between food outlet exposure and fruit and vegetable intake. Methods. We supplemented data from the 2006 Health Behavior in School Aged Children Study (n = 6, 096) with geocoded food outlet information surrounding schools (n = 80). We used multilevel logistic regression to examine associations between infrequent fruit and vegetable intake and supermarket and fast food outlet concentration, stratified by family social class. Results. Boys and older children were most likely to eat fruit and vegetables infrequently. High fast food outlet exposure was marginally significant for low fruit intake in low social class children only. Children from middle and low social class backgrounds attending schools with combined high fast food outlet/low supermarket exposure were most likely to report infrequent fruit intake (OR(low) = 1.60; CI: 1.02-2.45; OR(mid) = 1.40; CI: 1.03-190). Children from low social class backgrounds were also likely to report infrequent vegetable intake, given low supermarket and high fast food outlet exposure (OR = 1.79; CI: 0.99-3.21). Conclusion. Our findings suggest social class modifies the relationship between intake and food outlet concentration. School interventions improving fruit and vegetable intake should consider neighborhood surroundings, targetting older children from low social class backgrounds.

Validation of presence of supermarkets and fast-food outlets in Copenhagen: case study comparison of multiple sources of secondary data.

OBJECTIVE: We examined the quality of food outlet addresses provided by secondary sources and determined whether they could be physically located in the field. DESIGN: Addresses of food outlets in fourteen school districts in the northern part of Copenhagen were obtained from multiple business locators. We geocoded 202 addresses using a geographic information system and cross-referenced the sources against each other using a validation grid. Physical presence was determined via street survey. We applied gamma statistics and calculated positive predictive value, sensitivity and percentage agreement to assess the overall correspondence between our test of physical presence and each source of secondary information. SETTING: The study took place within city boundaries of Copenhagen, Denmark. SUBJECTS: Food outlets within fourteen school districts within Copenhagen. RESULTS: Positive predictive value between field results and secondary sources indicated good to excellent correspondence (range: 0·81-0·98), comparable with other studies. Gamma coefficients indicated low to high positive correspondence (range: 0·23-0·98). CONCLUSIONS: Despite moderately high correspondence between secondary sources of address information and field observation, the findings illustrate that the use of combined sources is recommended.

Exposure to physical activity resources by neighborhood sociodemographic characteristics in Copenhagen.

BACKGROUND: To investigate socioeconomic patterning of physical activity resources in Copenhagen. METHODS: We used multivariate logistic regression analysis to examine the association between physical activity-supportive resources [public open space (POS), cycling and walking paths, sports facilities, and intersection density] and neighborhood sociodemographic indicators (low education, recent immigrants, children under 15 yr, and household income). RESULTS: Neighborhoods with high proportions of residents with low education were most likely to have POS (OR = 2.63; CI: 2.10-3.29), paths (OR = 3.60; CI: 2.84-4.56) and sports facilities (OR = 5.96; CI: 4.31-8.24). Mid-to-low income areas were less likely to contain POS (OR = 67; CI: 0.49-0.90), paths (OR = 0.36; CI: 0.26-0.50), and sports facilities (OR = 0.48; CI: 0.30-0.77). Areas with children were less likely to have connected streets (OR = 0.51; CI: 0.31-0.83) but more likely to have POS (OR = 1.40; CI: 1.15-1.70) and paths (OR = 1.52; CI: 1.25-1.85). CONCLUSIONS: Residents living in areas with high proportions of low education or young children are likely to have high exposure to physical activity resources. Exposure to physical activity resources in Copenhagen may not explain the inequalities in physical activity behavior. Further examination of exposure to built environment resources is warranted.

Supermarket and fast-food outlet exposure in Copenhagen: associations with socio-economic and demographic characteristics.

OBJECTIVE: To investigate whether exposure to fast-food outlets and supermarkets is socio-economically patterned in the city of Copenhagen. DESIGN: The study was based on a cross-sectional multivariate approach to examine the association between the number of fast-food outlets and supermarkets and neighbourhood-level socio-economic indicators. Food business addresses were obtained from commercial and public business locators and geocoded using a geographic information system for all neighbourhoods in the city of Copenhagen (n 400). The regression of counts of fast-food outlets and supermarkets v. indicators of socio-economic status (percentage of recent immigrants, percentage without a high-school diploma, percentage of the population under 35 years of age and average household income in Euros) was performed using negative binomial analysis. SETTING: Copenhagen, Denmark. SUBJECTS: The unit of analysis was neighbourhood (n 400). RESULTS: In the fully adjusted models, income was not a significant predictor for supermarket exposure. However, neighbourhoods with low and mid-low income were associated with significantly fewer fast-food outlets. Using backwise deletion from the fully adjusted models, low income remained significantly associated with fast-food outlet exposure (rate ratio = 0·66-0·80) in the final model. CONCLUSIONS: In the city of Copenhagen, there was no evidence of spatial patterning of supermarkets by income. However, we detected a trend in the exposure to fast-food outlets, such that neighbourhoods in the lowest income quartile had fewer fast-food outlets than higher-income neighbourhoods. These findings have similarities with studies conducted in the UK, but not in the USA. The results suggest there may be socio-economic factors other than income associated with food exposure in Europe.

Secular trends in fruit intake among Danish schoolchildren, 1988 to 2006: changing habits or methodological artefacts?

BACKGROUND: Intermittent monitoring of fruit and vegetable intake at the population level is essential for the evaluation and planning of national dietary interventions. Yet, only a limited number of studies on time trends in fruit and vegetable intake among children and adolescents have been published internationally. In Denmark, national comprehensive campaigns to enhance fruit and vegetable consumption were initiated in 2001. This paper describes secular trends in fruit intake among Danish adolescents by six comparable school surveys from 1988 to 2006. The paper demonstrates and discusses the consequences of measurement changes introduced in long-term trend analyses. METHODS: We used Danish data from the international Health Behaviour in School-aged Children (HBSC) study collected in 1988, 1991, 1994, 1998, 2002 and 2006. Analyses were conducted on comparable questionnaire-based data from students aged 11, 13 and 15 total (n = 23,871) from a random sample of schools. Data on fruit intake were measured by a food frequency questionnaire. Due to changes in number of response categories beween surveys, different cut-points were analysed. RESULTS: The prevalence of students eating fruit at least once daily ranged from 78.3% among 13-year-old girls in 1988 to 17.3% among 15-year-old boys in 2002. Based on the six data collections, analyses of trends showed a significant decrease in prevalence of students eating fruit at least once daily from 1988 to 2002 (all p-values < 0.0001). In all age and gender groups, a significant increase in intake occurred between 2002 and 2006 (all p-values < 0.0065). Analyses of alternative cut-points revealed similar results. CONCLUSION: Fruit consumption among Danish schoolchildren decreased from 1988 to 2002 with an increase since 2002. We suggest that the increase may be attributable to a nation-wide initiative conducted in Denmark since 2001 to increase the intake of fruit and vegetables in the population. Still, the results imply that a substantial proportion of Danish schoolchildren do not meet the nationally recommended daily intake of fruit. Our analyses indicate that the observed trends are not solely caused by methodological biases related to changes in measurements.