Understanding African American Women's Decisions to Buy and Eat Dark Green Leafy Vegetables: An Application of the Reasoned Action Approach

Abstract

Objective

Examine intentions to buy and eat dark green leafy vegetables (DGLV).

Design

Cross-sectional survey assessing demographics, behavior, intention, and Reasoned Action Approach constructs (attitude, perceived norm, self-efficacy).

Setting

Marion County, Indiana.

Participants

African American women responsible for buying and preparing household food.

Main Outcome Measure(s)

Reasoned Action Approach constructs explaining intentions to buy and eat DGLV.

Analysis

Summary statistics, Pearson correlations, and multiple regression analyses.

Results

Among participants (n = 410, mean age = 43 y), 76% and 80%, respectively, reported buying and eating DGLV in the past week. Mean consumption was 1.5 cups in the past 3 days. Intentions to buy (r = 0.20, P < .001) and eat (r = 0.23, P < .001) DGLV were positively associated with consumption. Reasoned Action Approach constructs explained 71.2% of the variance in intention to buy, and 60.9% of the variance in intention to eat DGLV. Attitude (β = .63) and self-efficacy (β = .24) related to buying and attitude (β = .60) and self-efficacy (β = .23) related to eating DGLV explained significant amounts of variance in intentions to buy and eat more DGLV. Perceived norm was unrelated to either intention to buy or eat DGLV.

Conclusions and Implications

Interventions designed for this population of women should aim to improve DGLV-related attitudes and self-efficacy.

Introduction

Increased consumption of fruits and vegetables (FV) may help decrease disparities in diet-related health outcomes.¹ However, vegetable consumption in the US is low, and only 26% of adults meet national recommendations.2, 3 Vegetable consumption is even lower among minority populations (ie, Mexican Americans and African Americans [AA] relative to Whites).⁴ Vegetables in the “dark green” group, as identified by the US Department of Agriculture, are both cruciferous and leafy (eg, spinach, broccoli, romaine lettuce, watercress, Swiss chard, kale, collard, and mustard greens). Although they are the most nutritious group, dark green vegetables are also the least consumed.5, 6, 7 They are rich sources of vitamins A and C, folate, and β-carotene, and they provide numerous health benefits (eg, reduced risk of cardiovascular diseases).7, 8, 9, 10 The importance of consuming dark green leafy vegetables (DGLV) is highlighted in the US Department of Health and Human Services National Healthy People 2020 policy statement (ie, increase the proportion of dark green vegetables consumed by Americans) and the Dietary Guidelines for Americans (ie, women should consume 1.5 cups of DGLV per week, and men should consume 1.5–2 cups per week).5, 8, 11

The diets of AA have been of particular interest to researchers; Kirkpatrick, Dodd, Reedy, and Krebs-Smith posited that such racial minority populations could potentially benefit from eating more DGLV.4, 12, 13, 14, 15 There is no single “typical” eating pattern to which all AA ascribe,¹³ and studies indicate that DGLV are common in the AA culture and have been since the Atlantic slave trade. Specifically, during this time, dark green vegetables (eg, spinach and various types of greens) and other vegetables (eg, sweet potatoes, okra, squash) were brought from Africa to America.16, 17, 18, 19 Although DGLV remain an important and cultural component of some AA diets, determinants of their consumption have yet to be fully understood.20, 21, 22 To identify these determinants, it has been recommended that DGLV be studied separately from fruit and other types of vegetables (eg, red, orange), a practice not often reported in the literature.²³

Although an examination of DGLV eating behaviors is important, there is an expressed need to examine behavioral domains beyond eating,¹⁴ given that eating is the most distal behavior relative to buying and preparing food.²⁴ African American women have been described as being household “gatekeepers” who are primarily responsible for buying and preparing food.²⁵ They often take pride in this role and have intentions to share food among family, friends, and those who are in need.²⁶ These notions support findings that characterize AA women as dietary change agents who influence familial consumption of healthful food such as FV.12, 13, 27, 28 Therefore, the current study sought to expand the DGLV evidence base by using behavior change theory to explore intrapersonal factors associated with intentions to buy and eat more DGLV among a sample of midwestern AA women who buy and prepare household food.

The Reasoned Action Approach (RAA) is a theoretical model of behavior change that has been used to identify beliefs underlying people's behavioral decisions. The theory is the latest formulation of the Theory of Planned Behavior, and it assumes that one's intention is the most immediate predictor of behavior.²⁹ According to the RAA, there are 3 global constructs that determine one's intention to perform a behavior: (1) attitude toward a behavior; (2) perceived norms about performing a behavior; and (3) self-efficacy about performing a behavior.29, 30 The RAA and its constructs have been used to understand behaviors associated with obesity and chronic disease prevention,31, 32 as well as determinants of AA fruit and vegetable consumption.14, 33, 34 Such studies have supported the use of RAA constructs in explaining general variations in FV consumption among AA, but few studies have focused specifically on DGLV in this population.

In this study, the RAA was used to understand a sample of AA women's intentions to perform 2 behaviors: (1) eat more cups of DGLV each week over the next 3 months; and (2) buy more DGLV each week over the next 3 months. When using the RAA, behaviors are defined in terms of the target, action, context, and time.³⁵ Intention to eat and intention to buy are the chosen action elements. “More” (vs a specific number of cups) was selected as the target to reflect Healthy People 2020's recommendation to eat a higher proportion of DGLV.¹¹ Given that DGLV recommendations are based on weekly consumption, “each week” is the context.⁵ “Three months,” which has been used in previous RAA research, was chosen as an appropriate time interval to initiate behavior change.20, 22