You will be presented with a collection of medical randomized controlled trial (RCT) reports addressing a shared clinical question -- for instance, the efficacy of a medical intervention on a disease or condition. Given the titles and abstracts of these reports, your task is to generate the conclusion of the systematic review article synthesizing the key findings. Your conclusion should be a few sentences long. In your response, include only the conclusion and no other text. The RCT reports are below.



Title 1:
Neighbourhood differences in diet: the Atherosclerosis Risk in Communities (ARIC) Study.
Abstract 1:
STUDY OBJECTIVE : To investigate whether neighbourhood characteristics are related to dietary patterns independently of individual level variables . DESIGN : A cross sectional analysis of the relation between neighbourhood median household income and food and nutrient intakes , before and after adjustment for individual level variables . SETTING : Four United States communities ( Washington Co , MD ; Suburban Minneapolis , MN ; Forsyth Co , NC , and Jackson , MS ) . PARTICIPANTS : 13,095 adults aged 45 to 64 years participating in the baseline examination of the Atherosclerosis Risk in Communities ( ARIC ) Study , a prospect i ve study of atherosclerosis . MEASUREMENTS AND MAIN RESULTS : Information on diet and individual level income was obtained from the baseline examination of the ARIC Study .  Diet  was assessed using a semi-quantitative food frequency question naire . Information on neighbourhood ( census defined block groups ) median household income was obtained from the 1990 US Census . Multilevel models were used to account for the multilevel structure of the data . Living in lower income neighbourhoods was generally associated with decreased energy adjusted intake of fruits , vegetables , fish , and increased intake of meat . Patterns generally persisted after adjustment for individual level income , but were often not statistically significant . Inconsistent associations were recorded for the intake of saturated fat , polyunsaturated fat , and cholesterol . Overall , individual level income was a more consistent predictor of diet than neighbourhood income . CONCLUSION : Despite limitations in the definition and characterisation of neighbourhoods , this study found consistent ( albeit small ) differences across neighbourhoods in food intake , suggesting that more in depth research into potential neighbourhood level determinants of diet is warranted


Title 2:
Relative validities of 3-day food records and the food frequency questionnaire
Abstract 2:
The food frequency question naire ( FFQ ) has been used as an important dietary assessment tool in epidemiologic studies , but the usefulness of the FFQ has been debated in recent years . This study was performed to evaluate the relative validities of 3-day food records and the semi-quantitative FFQ .  A total of 124 subjects finished 3-day food records ( FRs ) during each of the four seasons , as well as the  FFQ  from December 2002 to May 2004 . The FFQ was a food based semi-quantitative FFQ including 103 items . Three-day FRs from each season and a r and omly selected season were compared with the remaining 9-day FRs . The remaining 9-day FRs , as a reference measurement , were also compared with the FFQ . Pearson 's correlation coefficients between the 3-day FRs and the 9-day FRs were between 0.14 and 0.56 . Pearson 's correlation coefficients between the FFQ and the 9-day FRs ranged between 0.07 and 0.41 . Average proportions of classification into the same quartiles , adjacent quartiles , and distant quartiles between the 3-day FRs and the 9-day FRs were 35.8 % , 40.5 % , and 5.2 % , respectively . On average , the proportions of classification into the same quartiles , adjacent quartiles , and distant quartiles between the FFQ and the 9-day FRs were 31.1 % , 39.4 % , and 6.9 % , respectively . Three-day FRs showed higher correlations and higher agreement proportions of quartile classification with the 9-day FRs than did the FFQ , but both relative validities of 3-day FRs and the FFQ appear to be acceptable as dietary assessment tools . Further studies for validating food intake by reliable biomarkers are necessary


Title 3:
Out and about: association of the built environment with physical activity behaviors of adolescent females.
Abstract 3:
Locational data , logged on portable GPS units and matched with accelerometer data , was used to examine associations of the built environment with physical activity and  sedentary behaviors of adolescent females . In a sample of 293 adolescent females aged 15 to 18 years old in Minneapolis and San Diego , the built environment around each GPS point and its corresponding sedentary , light , and moderate-to-vigorous intensity physical activity was examined using r and om intercept multinomial logistic regression models . The odds of higher physical activity intensity ( 3-level outcome : sedentary , light , MVPA ) were higher in places with parks , schools , and high population density , during weekdays , and lower in places with more roads and food outlets . Underst and ing the places where physical activity and sedentary behaviors occur appears to be a promising strategy to clarify relationships and inform policy aim ed at increasing physical activity and reducing sedentary behaviors


Title 4:
Choice and availability of takeaway and restaurant food is not related to the prevalence of adult obesity in rural communities in Australia
Abstract 4:
OBJECTIVES : To establish whether choice and availability of takeaway and restaurant food consumption are associated with increased obesity .  DESIGN : Crossroads Undiagnosed Disease Study : a cross-sectional study undertaken between June 2001 and March 2003 . SETTING : A regional centre and six shire capitals of variables size in rural Victoria , Australia . PARTICIPANTS : In total , 1454 residents of r and omly selected households . MEASUREMENTS : Obesity ( by body mass index ( BMI ) or waist circumference ) , weekly recreational activity , self-reported frequency of takeaway consumption , number of local takeaway and restaurant food outlets in the area . RESULTS : The prevalence of obesity ranged from 25.5–30.8 % and was higher than the general Australian population among both men and women . Those in the regional centre were less likely than those in large and small shire capitals to participate in recreational activity of 150 min or more ( 39.7 vs 48.4 % , 46.0 % respectively , P=0.023 ) and yet reported better access to facilities and amenities for physical activity . Recreational activity of ≥150 min/week was associated with 0.75 ( 0.58–0.97 ) fold less risk of obesity . BMI was unrelated to takeaway consumption . Waist circumference was significantly lower among those eating no takeaways , but similar whether takeaways were consumed < 1/month or ≥1/week . Increased takeaway consumption was associated with increased consumption of higher fat preparations of dairy and meat products . Availability of takeaway outlets and restaurants was unrelated to obesity . CONCLUSION : The obesity epidemic exists among those without significant consumption of or availability to takeaway foods . In a setting of easy availability of food , the obesity epidemic relates strongly to reduced physical activity , but not to consumption of takeaway food


Title 5:
Body mass index in elementary school children, metropolitan area food prices and food outlet density.
Abstract 5:
OBJECTIVE The aim of this study was to examine the association between food prices and food outlet density and changes in the body mass index ( BMI ) among elementary school children in the USA . METHODS The Early Childhood Longitudinal Study followed a nationally representative sample of kindergarten children over 4 years . We merged  individual-level data to ( a ) metropolitan data on food prices and ( b ) per capita number of restaurants , grocery stores and convenience stores in the child 's home and school zip code . The dependent variables were BMI changes over 1 and 3 years . We analysed mean changes with least-squares regression , and median changes and 85th percentile changes with quantile regression . We controlled for baseline BMI , age , real family income and sociodemographic characteristics . RESULTS Lower real prices for vegetables and fruits were found to predict a significantly lower gain in BMI between kindergarten and third grade ; half of that effect was found between kindergarten and first grade . Lower meat prices had the opposite effect , although this effect was generally smaller in magnitude and was insignificant for BMI gain over 3 years . Differences across subgroups were not statistically significant due to smaller sample sizes in subgroup analyses , but the estimated effects were meaningfully larger for children in poverty , children already at risk for overweight or overweight in kindergarten , and Asian and Hispanic children . There were no significant effects for dairy or fast-food prices , nor for outlet density , once we had controlled for individual characteristics and r and om intercepts to adjust st and ard errors for the sampling design . DISCUSSION The geographic variation in fruit and vegetable prices is large enough to explain a meaningful amount of the differential gain in BMI among elementary school children across metropolitan areas . However , as consumption information was not available , we can not confirm that this is the actual pathway . We found no effects of food outlet density at the neighbourhood level , possibly because availability is not an issue in metropolitan areas
Associations between observed mobility patterns in the food environment and diet related outcomes were equivocal .
Findings agreed that traditional food exposure measures overestimate the importance of the home food environment .