Health disparities stem from structural problems, including relative poverty, social exclusion, and limited opportunity ( ₁₈ ). Poverty rates in this country are higher than for most other industrialized nations, and child poverty rates have continually worsened since 1970 ( ₁₉ , ₂₀ ). Thus, for U.S. public health efforts to be effective, health promotion, not merely health education, must become the standard. The described study was focused on developing and piloting two instruments to explore external factors as variables in households' capacities for optimal nutrition. Measures of U.S. household food security have examined income and marital status, but not education levels, perceived adequacy of nutrition information and cooking skills, or household access to vehicles – all of which might be of interest in determining root causes of food insecurity.

Robertson, Brunner, and Sheiham ( ₂₁ ) argued that improving food choices will involve all aspects of the food system. Unfortunately, as the magnitude of food industry advertising indicates, corporations do everything possible to make unhealthy foods the easy choices. This factor, with the impacts of politics, economics, socioeconomic status, environment, and science and technology, makes it imperative to explore the possibilities for effective nutritional health promotion as they relate to barriers faced by individuals.

New Mexico is among the poorest states in the nation and Doña Ana County is one of its poorest counties ( ₂₂ ). Thus, Foley's and Pollard's ( ₂₃ ) suggestion that health promotion efforts often are least accessible by the poor provides an added incentive for public health professionals in New Mexico to determine other factors and health promotion methods with the potential to affect long-term health outcomes.

Until recently, New Mexico was the most food insecure state in the nation ( ₂₄ , ₂₅ ), and it continues near the worst in child poverty ( ₂₆ , ₂₇ ). Exploring households' food procurement barriers, food security status, and the adequacy of food regularly purchased by local households with children may help health promotion efforts be more responsive to communities' situations, and thus more effective for child health outcomes. Las Cruces' population is the second largest in the state ( ₂₈ ). Knowing the factors influencing food choices for some Las Cruces households might help in exploring these factors for a large proportion of New Mexico's people.

The study was intended to address the following research questions. Is a USDA-adequate diet affordable in Las Cruces? Are there relationships between household food security status and shopper-reported education level, marital status, nutrition-related information, “most important factor” in making food purchasing decisions, and lack of household vehicle? Do shoppers answering one food security scale item positively report foods needed but not purchased more frequently than shoppers who do not? What is the relationship between household food security, income, and dietary variety (indicated by foods purchased Always or Often on the Food Inventory Profile)? Can instruments be designed to explore factors associated with household food security status and food purchasing decisions?

The food cost survey was limited to three Las Cruces stores. It was assumed that current local non-sale prices for a USDA-adequate market basket accurately represented the cost of purchasing these foods. Additionally, it was assumed that persons receiving packets completed the packets; that participants answered questions accurately; that participants had some knowledge of generally available nutrition information; and that participants could read English.

The present study was based on the social ecology model of health and wellness promotion ( ₂₉ ), taking into account individual, interpersonal, community, and societal factors in exploring health problems and their solutions. Green and Kreuter ( ₃₀ ) discussed social ecology as referring “less to the physical environment than to the dynamic social forces operating on the situation and the population” (p. 27), and recognized the reciprocal relationship between person and environment. Ecological approaches move beyond health education, incorporating tools to help people take charge of their own health. Recently, public health efforts have begun to shift from a focus on psychosocial factors to external factors such as availability, accessibility, skills and laws, and attitudes and behaviors of others including peers, health professionals, and employers. The current study was designed to assess the affordability and availability of food and to explore the possibility of creating tools with which to describe the social ecology of household food purchasing decisions in Las Cruces, New Mexico.

The Institutional Review Board at New Mexico State University approved the study protocol. A convenience sample of 98 participants was recruited in February and March, 2003 via intercept interviewing ( ₃₁ ) at two Las Cruces food stores. Price and availability data were collected from the three retailers on February 22 and 23, 2003, and were compared to the Thrifty Food Plan (TFP) index for February 2003.

Instruments were a modified version of the Short Form of the Household Food Security Scale ( ¹⁶ ); a Household Shopping Profile; and a Food Inventory Profile. The last two were new instruments, designed for pilot-testing in the study. As such, their validity and reliability are not known, but face validity was determined by having the instruments reviewed by three faculty members who are proficient in survey research and familiar with nutrition information. Validity was further assessed by the analysis of participant item responses, comments written on the instruments themselves, and comments made on a Participant Feedback form that directly solicited participant input. These comments were used to revise the two instruments. Reliability was assessed by calculating Cronbach's alpha, .65 standardized for the Household Shopping Profile, and by analyzing the comments received regarding the Food Inventory Profile.

To assess local food affordability, food costs at three retailers were surveyed using the Food Store Survey Instrument (FSSI) ( ₃₂ ), a list of 87 foods in 14 categories designed to reflect a “market basket” related to the Thrifty Food Plan. Using this instrument provides a snapshot of food affordability and access as indicators of community food security ( ³² ).

The Household Shopping Profile (HSP) contained 21 items to assess household demographic factors possibly associated with food purchasing decisions and food security status. Based upon a review of the literature, household size, household income level, vehicle access, nutrition knowledge and cooking skills, and kitchen facilities appeared to be relevant factors.

The Food Inventory Profile (FIP) is designed to assess household shoppers' estimates of their food purchases. FIP foods and categories are representative of the Food Guide Pyramid, and might be more similar to an everyday shopping list than FSSI foods. For example, the FSSI includes baking powder, reflecting the USDA's assumption that families shopping within the constraints of the TFP will prepare all meals, desserts, and snacks at home ( ¹⁷ ). In contrast, FIP foods were chosen based upon the assumption that families purchase prepared snacks and desserts more often than they prepare these foods. For families experiencing constrained food choices due to financial considerations or otherwise, time available for baking may be limited. Thus, items such as baking powder, sugar, and spices were not included in the FIP. It was hoped that making these changes would result in an instrument that would more closely reflect participants' practices.

The 6-item short form of the Household Food Security Scale (hereafter food security scale), ( ¹⁶ ) was chosen to lessen respondent burden and facilitate self-administration. Its reliability in measuring household level food insecurity is very similar to that of the long form ( ¹⁶ ). Permission to reformat the instrument for ease of self-administration was obtained (M. Nord, personal correspondence, January 24, 2003). The short form contains six items regarding households' access to adequate food. Response choices are, depending upon the question, “Always True,” “Sometimes true,” “Never true,” or “Don't know/Refuse to answer;” “Yes,” “No,” or “Don't know/Refuse to answer;” or “Almost every month,” “Some months, but not every month,” “Only one or two months,” or “Don't know/Refuse to answer.”

Of 98 participants recruited, 67 returned survey packets. Analyses were conducted using SAS version 8 (SAS Institute Inc. Cary, North Carolina). Fisher's Exact test was used to determine independence of food security status in relation to each variable of interest.

A study limitation was that income was reported as a household size and income category combined choice, and that the income categories in the response choices (HSP question 4) were broad. The decision to offer category choices was made to increase income item response. Income categories were based upon the 2003 Federal Poverty Guidelines ( ₃₃ ). Based upon these guidelines, categories represented incomes from (1) poverty level to (5) 300% of the poverty level or higher.

Because some participants did not answer all items, counts and percentages may vary. All counts, percentages, and statistics were calculated on an item-by-item basis, and thus may or may not represent the total sample of 67 participants. Additionally, ethnicity and gender were not used as variables for analysis.

Participants were 49 females and 18 males stating that they had primary food shopping responsibility for their households. Ten were single, 13 reported living with someone, 33 were married, 8 were divorced, and two widowed. One participant did not report marital status. Seven participants lived alone, 25 in 2-person households, 16 in 3-person households, 10 in 4-person households, and 9 in households with five or more members. Twenty-three were college graduates, 21 had completed some college, 16 were high school graduates, 5 had not completed high school, and 2 had not attended high school. Fourteen participants reported income category 1, five category 2, nine category 3, fourteen category 4, and 17 category five.

Data were collected from the three retailers on February 22 and 23, 2003, and were compared to the Thrifty Food Plan (TFP) index for February 2003. Store 1 is a large discount retailer, and Stores 2 and 3 are supermarket chains. The weekly TFP budget, during February 2003, of a USDA-adequate diet for a family of four (children aged 2 to 5 years) was $93 ( ¹⁷ ). For a family of four with children 6 to 11 years old, the weekly budget for this diet increased to $107.70 ( ¹⁷ ).

The cost of TFP-recommended food at Store 1 was $87.31. At Store 2, the total cost was $94.23, and at Store 3, the total was $111.57. Thus, for a family with children under the age of 6, Store 1 was the only affordable option based upon the February 2003 TFP index. A family of four with children aged six to eleven could afford the recommended foods at stores 1 and 2, but not at Store 3. Cost differences by store were found within food categories, and for some categories Store 3's costs were lower than at stores 1 and 2. However, overall higher food costs at Store 3 resulted in higher total food cost for the TFP market basket.

Of 67 survey packets returned, 5 food security instruments were not completed. According to USDA protocol, households with zero or one positive response were scored FS (Food Secure), households with two or three positive responses were scored FI (Food Insecure), and households with four or more positive responses were scored FIH (Food Insecure with Hunger) ( ¹⁶ ). Of 33 food security scales received from Hispanic participants, 21 (63.6%) were coded as FS, 7 (21.2%) as FI, and 5 (15.2%) as FIH. Of 29 received from non-Hispanic participants, 19 (65.5%) were coded as FS, 8 (27.6%) as FI, and 2 (6.9%) as FIH. Overall, of 62 SFHFSS received, 40 (64.5%) were coded as FS, 15 (24.2%) as FI, and 7 (11.3%) as FIH.

To explore the relationship between food security, income, and food purchasing decisions, variety of food purchased was compared for participants coded as high income, food secure; high income, food insecure; low income, food secure; and low income, food insecure. Table 1 presents food security status by income category, and Table 2 presents variety of foods purchased by food security and income categories.

Figure 1

Table 1: Food Security Score by Lower- and Higher-Income Categories

Figure 2

Table 2 : Variety of Food Purchased by Income and Food Security Category

While a household scoring 1 is considered food secure, a positive response means choosing “Sometimes True” or “Often True.” Thus, it is doubtful whether a participant answering even one item positively would consider his or her household food secure. Given this potential discrepancy between official food security status and household reality, it was thought that households with one positive response might differ from households with none, even while being deemed officially food secure. Fisher's Exact test was used to determine if participants answering one food security item positively reported foods needed but not purchased due to cost more frequently than participants answering zero items positively. Of the 40 households coded as FS, 10 (25%) had responded positively to one food security item.

The Fisher's Exact score for the above research question was <.01, when food insecure households were included. The difference was seen between households scoring 0 and households scoring 2 or greater, with no difference detected between households scoring 0 and households scoring 1. Thus, not purchasing needed foods because of cost was independent of a food security scale score of 1. However, as shown in Table 3, 60% of households with a score of 1 reported not purchasing needed foods due to cost.

Figure 3

Table 3 : Food Security Score by Foods Needed but not Purchased

Only 16.7% of households with a score of 0 reported this experience. Similarly, 40% of households scoring 1 reported that they purchased all needed foods, while 83.3% of households scoring 0 reported that they purchased all needed foods. Thus, a case may reasonably be made for examining further the appropriateness of categorizing households with a score of 1 as food secure.

All returned packets contained HSPs that were complete, or nearly complete. Of its 21 items, six addressed variables (education, marital status, nutrition information, most important factor in food purchasing, foods needed but not purchased, and vehicle availability) thought to be of interest in relation to food security score. Fisher's Exact Test (p<.01) indicated a relationship between marital status and food insecurity, as shown in Table 4.

Figure 4

Table 4 : Food Security Score by Marital Status

Food security status was found, for this sample, to be independent of the 5 other variables.

Food insecurity in a wealthy society such as the United States is a complex, multi-factorial problem, and one that should be addressed by strategies that take into account the various levels and settings within which it occurs. An effective health promotion campaign surrounding food choices might take into account such ecological factors as price, availability, transportation access, food preparation and preservation skills and facilities, literacy, and time not devoted to the pursuit of paid employment ( ₃₅ ). Such a campaign might teach its audience quick, easy, and healthy food preparation, as well as advocacy skills necessary to exercise community power and enter into dialog with local stores, and work with neighborhoods to develop systems of social support. While health education campaigns assume complexity based on “market segmentation” but simultaneously aim to generalize strategies across various regions, nutrition-oriented health promotion efforts might be more likely to succeed if tailored to specific communities and even neighborhoods.

Health promotion efforts may need to include situation-specific approaches as a matter of course, rather than as exceptions to general practice. Schorr ( ₃₆ ) cited research into “best practices” of antipoverty programs:

the working group found very little that held true regardless of context. At their core, “successful programs recognize and respond to the needs of the community; they reflect the character of its people; . . . they build capacity in people and in neighborhoods . . . .” The council concluded “best practices are whatever works in a given context.” (pp. 7-8)

Such programs would necessarily entail complicated assessment and planning stages, but would likely produce long-term, sustainable food security solutions.