Measuring the food service environment: development and implementation of assessment tools.
Minaker, Leia M. ; Raine, Kim D. ; Cash, Sean B. 等
The obesity epidemic is influenced by social, cultural, economic
and physical contexts. (1-4) The accessibility, availability and
affordability of foods have an impact on food purchasing and consumption
behaviours. Access to healthy foods has been related to certain
neighbourhood characteristics. Specifically, access to healthy foods is
increased in higher-income neighbourhoods. (5,6) Conversely,
lower-income neighbourhoods may have increased access to fast food
restaurants. (7,8) Residents' diets have been found to correlate
with their food environment, particularly in lower income and minority
populations. (5,6,9,10) There are few published conceptual models of the
food environment (3,11) and, until recently, even fewer tools to assess
it. (12-14) This paper describes the development and implementation of
food environment assessment tools.
METHODS
Setting
Data were collected between January and May 2006 at the University
of Alberta, which covers 50 square city blocks in a city of
approximately one million people. The campus is workplace, school or
home to at least 45,000 people and thus was deemed an appropriate
setting in which to conduct the current study.
All food service outlets, defined as outlets preparing and serving
food for immediate consumption, within the geographic boundaries of the
campus were defined as the sample. Convenience stores (n=10) were
excluded from the sample as the primary purpose of most convenience
stores was not service of prepared meals. There were no grocery stores
in the geographic area of study.
Measures
Measures were based on Glanz and colleagues' conceptual model
of community nutrition environments. (3)
Community Nutrition Environment
Measures included the type and number of each food outlet in the
community and reflected the accessibility of food service outlets.
Food outlet types were defined as Asian, burger outlets,
cafeterias, coffee shops, pizza places, sandwich shops (main products
are "subs", pitas or sandwiches), sit-down restaurants and
smoothies outlets (i.e., outlets serving mostly dairy-based beverages
blended with fruit or juice). The number of outlets in each category was
tallied.
Consumer Nutrition Environment
Food availability: The number of healthy and unhealthy options of
main meals, snacks and beverages were assessed for each type of food
outlet type described above. "Healthy" and
"unhealthy" foods were defined using the 2005 British Columbia
Ministry of Education and Ministry of Health food classifications, (15)
as at the time of the study these were the only publicly accessible
Canadian food classification guidelines available for educational
institutions. Classifications are based on total energy (kcal) per
serving, amount of processing and key nutrients (including saturated
fat, trans fat, sodium and sugar). Healthy foods and beverages were
considered those in the "Choose Most" or "Choose
Sometimes" categories.
Convenience: Wait times at each establishment and hours of
operation were recorded as measures of convenience. Wait times were
measured by calculating the difference between the time a customer
entered a line-up during the lunch hour and the time the customer was
handed his or her food. Wait times of sit-down restaurants were not
assessed; for these, we assumed a slower service and lower convenience
than fast-food outlets.
Additionally, the mean number and range of weekday and weekend
hours of operation were calculated. Other indicators of convenience,
such as parking and drive-thru service, were not measured, as the
setting of this community (a university) precluded meaningful
assessment. Specifically, the vast majority of outlets were located
within main buildings on campus and thus had neither parking nor
drive-thru service.
Food affordability: "Typical" foods, those predominantly
advertised within an outlet or that were observed as commonly ordered
items, were selected by the first author. Food price, food weight (g)
and energy content were used to determine the energy density
(kilocalories per gram) and energy cost ($Cdn/100 kcal). (16) Details of
these methods, analyses and results are reported elsewhere (unpublished
data: Minaker, Raine, Cash, 2007).
Food promotion: The number and subject of promotions within each
outlet were assessed. Promotions were coded into one of the following
categories: unhealthy, healthy and overeating. The previous definitions
of healthy and unhealthy were used to code the promotions. (15) In
addition, promoting healthier preparation options (defined as any
alternative method of preparing the same food to have a higher
nutritional value or be lower in salt, fat or sugar) also counted as a
"healthy" promotion. Advertising "sizing up" for
value (e.g., "Super-size", "Jumbo", or "All you
can eat" options) was classified as promoting overeating. Each
advertisement was coded in up to two categories (e.g., Super-size
options for burger and fries combinations were coded as both unhealthy
and overeating).
Nutrition information: Nutrition information, information about the
nutritional content of the food, was considered "available" if
it could be found online or within the food outlet. The number of items
with health-related labels on the menu was also recorded.
Analysis
Quantitative data were analysed using SPSS 12.0 for Windows (SPSS
Inc., Chicago, IL, 2003). For each inferential statistical test, a
p-value of [less than or equal to] 0.05 represented statistical
significance.
Consumer Nutrition Environment
Food availability: Means and ranges of food availability data were
reported where appropriate. In addition, the mean proportions of healthy
main meals, snacks and beverages and specific food availability were
regressed on categorical "dummy" variables representing each
outlet type minus one "base case" that was varied to provide a
complete set of pairwise comparisons. This form of dummy variable
regression is equivalent to the use of a one-way ANOVA comparing all
outlet types.
Convenience: To establish whether the hours of operation differed
across outlet type, linear regressions were performed between weekday or
weekend hours of operation and outlet type. Wait times were also
regressed on outlet type.
Food promotion within food outlets: The number of advertisements
and the corresponding proportion of each advertisement type were
calculated. The mean proportions of the subject matter categories were
regressed on outlet type.
Nutrition information: The proportions of outlets with
health-related menu labels, the mean proportion of items labelled and
the proportion of outlets with available nutrition information were each
regressed on outlet type.
Composite rankings: To assess how these different food outlets were
related to food choice constructs at an environmental level, measures
developed to assess the nutrition environment were grouped into
categories reflecting overall convenience, cost/value, health and
health-promoting food advertising within outlets. Because of the diverse
units of measurement used for the various observed measures, outlet
types were ranked in each category. Ranks of each column were averaged
to obtain the final rank of each outlet type. Where averages were
identical, the same rank was given. Measures related to convenience were
the number of outlets, hours of operation and wait times, and they were
ranked such that the most convenient situations were ranked before less
convenient situations. Measures in the cost/value grouping were
super-size options, mean energy cost and mean energy density of typical
foods. Outlets were ranked such that situations of higher value (in
terms of energy) for the dollar were ranked before lower value
situations. Measures related to health were the proportion of healthy
food options available, healthier preparation options, specific healthy
item availability, health-related food labels and availability of
nutrition information; these were ranked such that healthier situations
were ranked before less healthy situations. Finally, outlet types were
ranked according to the three categories of promotions found within food
outlets. Outlets were ranked such that more healthful promotions were
ranked before less healthful promotions. Spearman's rho was used to
formally investigate this hypothesis.
RESULTS
Community Nutrition Environment
There were 75 food outlets within the geographic boundaries. Table
1 shows the number and proportion of total for each outlet type.
Consumer Nutrition Environment
Food availability: Seven of 75 food outlets offered super-size
options. Burger outlets were significantly more likely to super-size
than all other types of outlet (data not shown). Burger outlets and
pizza places had lower proportions of healthy main meals than all other
outlet types (range: p=0.000 when compared with Asian outlets to p=0.015
when compared with sit-down restaurants). Smoothies outlets had a higher
mean proportion of healthy main meals than coffee shops (p=0.006),
sandwich shops (p=0.006), and sit-down restaurants (p=0.008) (see Table
2 for number of outlets offering healthy main meals and proportion of
healthy items assessed).
Sandwich shops had a higher mean proportion of healthy sides and
snacks than coffee shops (p=0.034). All other comparisons were not
statistically significant (see Table 2). Of the 18 sandwich shops, 12
(67%) allowed whole-wheat bread choices instead of white bread, and did
so at no extra cost. Of the 10 cafeterias, 4 (40%) allowed whole-wheat
bread choices instead of white bread. One of the five burger shops
offered baked potatoes instead of French fries for no additional cost.
No other healthier preparation options were found on campus (data not
shown).
Convenience: Table 1 describes the mean wait times and hours of
operation associated with each outlet type. Cafeterias had longer wait
times than coffee shops (p=0.035). All other comparisons were
non-significant.
Food promotion within food service outlets: Table 3 compares
advertisements by food outlet types. All overeating advertisements also
advertised unhealthy foods. Pizza places had higher proportions of
unhealthy advertisements than all other outlet types. Smoothies outlets
had a lower mean proportion of unhealthy advertisements and a higher
mean proportion of healthy advertisements than all other outlet types.
Burger outlets had more overeating advertisements than all other outlet
types.
Nutrition information: Smoothies outlets were more likely to label
food on menus according to health or food content than Asian outlets
(p=0.002), burger outlets (p=0.021), cafeterias (p=0.019), pizza places
(p=0.012) and sit-down restaurants (p=0.017) (data not shown). Burger
outlets were more likely to provide nutrition information than Asian
outlets (p=0.025), cafeterias (p=0.001), coffee shops (p=0.030) and
sit-down restaurants (p=0.003). Sandwich shops were more likely to
provide nutrition information than were cafeterias (p=0.000) and
sit-down restaurants (p=0.005). Pizza places were more likely to provide
nutrition information than sit-down restaurants (p=0.032) and cafeterias
(p=0.009). All other comparisons were not significant (data not shown).
Composite rankings: As presented in Table 4, composite rankings of
outlet types that ranked higher in convenience and cost/value tended to
rank lower in health and healthy food promotions. There was a positive
correlation between convenience measures and cost/value measures
(r=0.67, n=8, p<0.10). There was a negative correlation between
cost/value measures and health (r=-0.74, n=8, p<0.05) and between
cost/value measures and healthy food promotions (r=-0.80, n=8,
p<0.05).
DISCUSSION
The measures developed, based on the literature to date and
consistent with recently published nutrition environment measures, (12)
yielded results consistent with expected outcomes, with some limitations
(discussed below). The logic of the findings suggests both face and
content validity. Future research is necessary to refine instruments, to
address identified limitations (minor) and to assess reliability.
The most common reasons why frequent patrons of fast-food
restaurants choose to patronize these restaurants are that they are
quick, convenient, inexpensive and sell tasty food. (17) People may also
consider health when making food choices, even when eating out. (18,19)
The vast majority of the food outlets in the current study were
fast-food restaurants--a broad category under which all outlet types in
the current study other than cafeterias and sit-down restaurants fell.
Although the current study did not address the "tastiness" of
the food across outlet types, other reasons given by consumers in making
food outlet choices were evaluated, including convenience, cost and
health. Using composite rankings of convenience, cost and health, this
study is the first to our knowledge to empirically show the relations
among convenience, cost and health for different types of food outlet.
The current study distinguished between types of fast-food outlet
with respect to the "health" of the outlets' food
environments. In other studies (12) fast-food outlets have been thought
to represent unhealthy food environments, and living in proximity to
such outlets has been related to obesity (20) and cardiovascular
outcomes. (21) Although the assumption that fast-food outlets represent
unhealthy food environments is reasonable, based on the evidence that
fast-food consumption is related to increased body mass index, (22-24)
the current study indicates that fast-food outlets are variable in the
health of their food environments. For example, burger outlets ranked
low in measures of health and healthy food promotions and higher in
convenience and cost/value. On the other hand, fast-food smoothies
outlets and sandwich shops ranked highly in health and healthy food
promotions and lower in convenience and cost/value. To further
illustrate the difference between types of fast-food outlets, burger
outlets had the lowest mean proportion of healthy main meal options (9%)
and smoothies outlets had the highest (96%). To include all types of
fast-food outlets under one definition or construct may be less precise
than specifying the type of fast-food outlet.
Following completion of this research, in 2007, the BC guidelines
used to define healthy vs. unhealthy foods (the key measure used in
assessing food availability within the consumer nutrition environment)
were revised to reflect the updated Canada's Food Guide. Major
revisions include further restricting the sodium and fat content of many
foods. This revision would likely alter the findings of this study
slightly by reclassifying certain foods as unhealthy rather than
healthy. Our findings could, therefore, be conservative.
Two measures developed in the current study--observing the
availability of super-size options and nutrition information--may be
less meaningful than originally thought. Every outlet that offered
super-size options (eight outlets) and/or nutrition information (26
outlets) were corporate franchises. The availability of nutrition
information may be more indicative of the company's resources to
have the nutrition content of food products evaluated than of whether
the foods served are healthy. Larger chains may be under more external
pressure to provide nutrition information.
Assessing the availability of nutrition information may not be a
useful expenditure of time or resources when assessing the food
environment, particularly given recent findings indicating that
consumers may not use or even understand nutrition information. (25,26)
Future research to refine the scoring system could address these
limitations.
Unhealthy food promotion was far more prevalent than healthy food
promotion. Of all outlet types, smoothies outlets advertised unhealthy
items least (25% of advertisements) and healthy items most (47% of
advertisements). Conversely, pizza places advertised unhealthy options
more (86% of advertisements) and healthy options very infrequently (only
3% of advertisements). Advertisements in food outlets may merely reflect
the food sold within the outlets. Indeed, it seems intuitive that the
proportion of healthy advertisements would reflect the proportion of
healthy items available. This measure may therefore be considered
redundant and thus a limitation in the scoring system. Alternatively, it
could be an easily applied proxy for the overall healthfulness of the
outlet. Further, it is possible that despite the availability of healthy
foods at fast food outlets, the promotion of even healthy foods could
contribute to over-consumption. Further research could investigate the
context of people's food choices in a variety of food service
settings.
This study attempted to comprehensively evaluate the food service
environment of a small community. It appeared that the current tool had
some redundancies and that certain components of the tool were less
useful than others. More research is needed to evaluate the worth of
each of the tools described here and to explicate the relation between
the food environment and residents' diets.
Acknowledgements: This research was supported by a scholarship to
Leia Minaker from the Social Sciences and Humanities Research Council
and funding support by POWER (Promoting Optimal Weights through
Ecological Research), a New Emerging Team in the Study of Obesity and
Healthy Body Weight, Canadian Institutes of Health Research (CIHR)/Heart
and Stroke Foundation of Canada (HSFC). Kim Raine acknowledges salary
support from the Alberta Heritage Foundation for Medical Research, CIHR
and HSFC.
Received: February 17, 2009
Accepted: August 15, 2009
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Leia M. Minaker, MSc, [1] Kim D. Raine, PhD, RD, [1] Sean B. Cash,
PhD [2]
Author Affiliations
[1.] Centre for Health Promotion Studies, School of Public Health,
University of Alberta, Edmonton, AB
[2.] Department of Rural Economy, University of Alberta, Edmonton;
Department of Consumer Science, University of Wisconsin--Madison,
Madison, WI
Correspondence and reprint requests: Kim D. Raine, PhD, RD, Centre
for Health Promotion Studies, School of Public Health, University of
Alberta, 5-10 University Terrace, 8303-112 St., Edmonton, AB T6G 2T4,
Tel: 780-492-4039, Fax: 780-4929579, E-mail: kim.raine@ualberta.ca
Table 1. Convenience of Accessing Food from Different Outlet Types
Type of Outlet Number Proportion of Mean Number
Total (%) of Weekday Hours
(SD)
Asian outlet 8 10.7 53 (13.1)
Burger outlet 5 6.7 65 (12.3) *
Cafeteria 13 17.3 39 (14.1)
Coffee shop 12 16.0 67 (20.3) *
Pizza place 8 10.7 55 (14.8) *
Sandwich shop 18 24.0 55 (18.1) *
Sit-down restaurant 6 8.0 65 (10.3) *
Smoothies outlet 5 6.7 34 (17.0)
Type of Outlet Weekday Mean Wait Wait Time
Hour Range Time in Range (min)
Minutes (SD)
Asian outlet 33-75 3.5 (3.3) 1-8
Burger outlet 53-86 2.7 (1.8) 1-4
Cafeteria 18-64 5.9 (4.0) 1-11
Coffee shop 38-120 2.8 (3.1) 0-8
([dagger])
Pizza place 25-75 3.8 (4.3) 0-11
Sandwich shop 20-80 4.2 (2.4) 1-10
Sit-down restaurant 55-81 n/a n/a
Smoothies outlet 30-70 2.3 (1.7) 0-4
* Indicates statistically significantly (p<0.05) longer mean
number of hours of operation than cafeterias, using regression
analysis with categorical independent variables.
([dagger]) Indicates statistically significantly (p<0.05) shorter
mean wait time than cafeterias, using regression analysis.
Table 2. Proportion of Healthy Meals, Sides and Beverages by Type
of Outlet
Type of Outlet Number * Mean % Healthy Number
Main Meals ([dagger])
Asian outlet 8 68 7
Burger outlet 5 9 5
Cafeteria 10 65 7
Coffee shop 5 47 12
Pizza place 7 12 5
Sandwich shop 18 53 16
Sit-down restaurant 5 47 5
Smoothies outlet 3 96 4
Type of Outlet Mean % Healthy Number Mean % Healthy
Sides or Snacks ([double Beverages
dagger])
Asian outlet 15 7 28
Burger outlet 14 4 28
Cafeteria 20 8 53
Coffee shop 11 12 32
Pizza place 21 6 22
Sandwich shop 32 17 29
Sit-down restaurant 27 5 24
Smoothies outlet 23 4 45
* Includes all establishments that serve main meals.
([dagger]) Includes all establishments that serve sides or snacks.
([double dagger]) Includes all establishments that serve beverages.
Table 3. Number and Proportion of Different Advertisement
Types * by Type of Outlet
Type of Outlet Number % Unhealthy
of Ads Ads ([dagger])
Asian outlets 40 65
Burger outlets 44 64
Cafeterias 141 60
Coffee shop 63 48
Pizza place 35 86
Sandwich shop 114 50
Sit-down restaurants 7 29
Smoothies outlets 55 25
Type of Outlet % Healthy % Overeating
Ads ([double Ads ([section])
dagger])
Asian outlets 20 10
Burger outlets 2 18
Cafeterias 25 1
Coffee shop 10 2
Pizza place 3 6
Sandwich shop 25 5
Sit-down restaurants 14 0
Smoothies outlets 47 0
* The percentage of each type of advertisement may not add up to
100% because the subject matter of some ads fell beyond the scope
of the four categories (e.g., ads for a contest). Alternatively,
the percentage of each type of ad may add up to more than 100%
because the subject matter of some ads was coded in up to two
groups (e.g., 12 ads focused on both unhealthy food and
overeating).
([dagger]) All outlets had a statistically significantly lower
mean proportion of unhealthy ads than pizza places; except for
sit-down restaurants, all outlets had a statistically
significantly higher mean proportion of unhealthy ads than
smoothies outlets.
([double dagger]) All outlets had a statistically significantly
lower mean proportion of healthy ads than smoothies outlets;
except for sit-down restaurants, all outlets had a statistically
significantly higher mean proportion of healthy ads than burger
outlets and pizza places; coffee shops had a statistically
significantly lower mean proportion of healthy ads than
cafeterias and sandwich shops.
([section]) All outlets had a statistically significantly lower
mean proportion of overeating ads than burger outlets;
cafeterias, coffee shops and smoothies outlets had a
statistically significantly lower mean proportion of overeating
ads than Asian outlets.
Table 4. Summary of Outlet Type Characteristics *
Outlet Type Convenience Cost/Value Health Healthy Food
Promotion
Asian outlet 3 4 7 6
Burger outlet 2 1 8 7
Cafeteria 5 6 4 3
Coffee outlet 1 2 5 5
Pizza place 3 3 6 6
Sandwich outlet 3 5 1 4
Sit-down restaurant 4 4 3 2
Smoothies outlet 3 7 2 1
* Rankings as noted in the text
