Papas MA, Alberg AJ, Ewing R, Helzlsouer KJ, Gary TL, Klassen AC. The built environment and obesity. Epidemiol Rev. 2007;29:129-43. Epub 2007 May 28. Review.

To examine the published empirical evidence for the influence of the built environment on the risk of obesity.

• a direct measurement of body weight(eg body mass index(BMI)
• at least one objective measure of the built environment
• english articles
• humam population
• January 1, 1966 and February 1, 2007

articles that examined neighborhood characteristics and obesity

Recruitment

A Medline search was conducted using the keywords "obesity" or "overweight" and "neighborhood" or "community".

A second search was conducted using the keyweords "obesity" or "overweight" and "built environment" or "environment"

Design

cross-sectional design (18/20)

longitudinal studies (2)

Blinding used (if applicable)

none

Intervention (if applicable)

none

Statistical Analysis

multilevel modeling

Timing of Measurements

cross section : 1966 to 2007

longitudinal studies: 3yrs, 7yrs

Dependent Variables

• Variable 1: BMI(weight(kg)/height(m)²)

Independent Variables

built environment

Control Variables

age

race/ethnicity

Initial N:

343

Attrition (final N):

20 studies

Age:

children

adolescent

adult

Ethnicity:

non-Hispanic white

African Americans

Hispanic

Other relevant demographics:

income

marital status

Anthropometrics

Adults

BMI > 25 and < 30 = overweight

BMI > 30 = obesity

children/adolescents

BMI > 85th percentile and < 95th percentile = overweight

BMI > 95th percentile = obesity

height

weights

Location:

United States

Australia

Europe

Key Findings

Diet:

• Studies examined access to physical activities opportunities or access to food outlets.
• Three of the four studies that examined density or food prices found positive associations with BMI.
• The number of residents per fast food restaurant and the number of square miles per fast-food restaurant were significantly(p<0.05) associated with the prevalence of obesity at the statewide level.
• Lower area food prices for fruits and vegetables were also associated decreases in BMI over a 3-year period for children aged 4 and 5 years.
• The presence of supermarkets was statistically significant with lower prevalence of obesity (prevalence ratio (PR) = 0.83(CI 0.75,0.92) and overweight (PR = 0.94, CI 0.90,0.98)
• The presence of convenience stores was statistically significantly associated with higher pervalence of obesity (PR=1.16, CI: 1.05, 1.27) and overweight (PR = 1.06, CI 1.02,1.10)
• The density of the food establishment per 1000 residents in each zip code was not associated with BMI for adults in the WISEWOMAN Study, statistical significance not mentioned.
• For adults, distance to the grocery store was associated with obesity; in comparison with persons who grocery store was within their census tract, persons who shopped more than 1.8 miles away had greater BMIs(β=0.78,p<0.05)

Physical Activity:

• There was no association with the distance from the child's residence to the playground and BMI
• Of the two studies in adults that computed the distance from the participants home to the recreational facility there was a positive association with an increase risk of overweight.
• The two studies investigating the number of recreational facilities within a census block in an adolescent population found a positive association with the risk of overweight.
• Mobley found a negative association with density and BMI (β= -1.39)
• Two studies examined measures of transportation found significant positive associations between the measures of use of motorized transportation and the risk of obesity.

17 out of 20 studies found a statistically significant relation between some aspect of built environment and risk of obesity.

Table 1: Summary of the evidence for an association between the built environment and the risk of obesity, by type of exposure measurement

Other Findings

Most articles reported a statistically significant positive association (84%) between some aspect of the built environment and obesity. Several methodological issues were of concern, including the inconsistency of measurements of the built environment across studies, the cross-sectional design of most investigations, and the focus on aspects of either diet or physical activity but not both.

An understanding of the built environment-obesity relation in different racial/ethnic groups may aid in the develpment of culturally specific community-level obesity prevention programs. Conflicting results were evident for the association between land-use mix and risk of obesity. The reasons are unclear.

Two studies reviewed were conducted outside of the US, limiting the generalizability of the findings to the non-US populations. Social patterning of food availability may not be as evident in other developed nations.

More research on the impact of the built environment on obesity is needed.

The review was difficult to conceptualize. The discussion did not follow the table in a systematic way. It was helpful that the author discussed the conflicting results of positive and negative associations within the same built environment. His statement that 17 out of 20 (84%) studies showed a positive association was helpful.

The discussion section concentrated on the study's limitations and did not give a overall summary of the results. It would have been helpful if the author would have given a final summary.