© 2002 by the American Diabetes Association, Inc.
A Controlled Evaluation of Staging Dietary Patterns to Reduce the Risk of Diabetes in African-American Women
1 George Warren Brown School of Social Work, Washington University, St. Louis, Missouri
OBJECTIVEThis study evaluated the 3-month follow-up data of the Eat Well, Live Well Nutrition Program, a culturally specific, peer-led dietary change program designed to reduce the risk of type 2 diabetes in low-income African-American women. This peer-led program was delivered in the community and was tailored to the participants stage of change for individual dietary patterns. We report the results of the 3-month intervention and the extent to which dietary changes and other key outcomes were maintained at a 3-month follow-up assessment. RESEARCH DESIGN AND METHODSUsing an experimental control group design, 294 overweight African-American women (ages 2555 years), recruited in collaboration with a neighborhood organization, completed pre- and posttest and 3-month follow-up interviews of dietary behaviors, knowledge, attitudes, fat intake, and weight. RESULTSSignificant reductions were found in fat intake among women in the treatment condition when compared with women in the control group; these reductions were maintained at 3-month follow-up assessment. Likewise, significant changes in dietary patterns were reported after the study and were maintained, except for one dietary pattern (replacement). CONCLUSIONSThis model of health promotion, which individually tailors dietary patterns through staging and use of peer educators, has the potential for decreasing fat intake and increasing and maintaining specific low-fat dietary patterns among overweight African-American women at risk for diabetes.
Abbreviations: EWLW, Eat Well, Live Well Nutrition Program FFQ, food frequency questionnaire
The prevention of type 2 diabetes among African-American women is critical because of the high rates of diabetes-related mortality and morbidity in this population. Among African-American women, diabetes is considered epidemic; the rate is 11.8% among women 20 years of age, and 25% among women >55 years of age. This is nearly twice the rate of Caucasian women (1). In addition, African-Americans experience higher rates of diabetes-related complications than Caucasians, such as eye disease, kidney failure, and lower extremity amputations. For example, the frequency of diabetic retinopathy is 4050% higher, and end-stage renal disease is four times more likely among African- Americans than Caucasians. Moreover, the overall mortality rate among African-American women is 40% higher compared with their Caucasian counterparts (2). One explanation for the higher rates of diabetes in this population is the higher amount of dietary fat consumed by AfricanAmericans when compared with Caucasians (3,4). Dietary patterns have been examined as a major risk factor contributing to type 2 diabetes. For example, in their description of the lifestyle risk factors for type 2 diabetes, Rewers and Hamman (5) indicated that higher dietary fat intake was associated with a higher risk of diabetes, even after adjusting for obesity, age, sex, ethnicity, fat distribution, and fasting insulin levels. Moreover, recent nutrition-related recommendations for diabetes prevention have indicated that reducing intake of total and saturated fat, independent of total calories, may reduce the risk of diabetes (6). This result may be explained by the adverse impact that dietary fat has on insulin sensitivity (6). Thus, changing dietary patterns to reduce fat intake may be important for reducing the risk of diabetes. To address this challenge, a community-based dietary change program, the Eat Well, Live Well Nutrition Program (EWLW), was delivered to African-American women at risk for diabetes. Its primary focus was to reduce dietary fat intake and increase low-fat dietary patterns by tailoring the intervention to participants readiness to make changes in their diet. Although weight reduction was encouraged, healthy eating through lowering fat in the diet was the major emphasis for recruitment and program content. Few dietary change programs use participants readiness to change as a method for individually tailoring program content. The stages of change theory, which guided the delivery of the EWLW program, asserts that change is a dynamic process occurring over these distinct stages (7): 1) precontemplation, the stage at which the person is unaware of the risk of their behavior or aware but unwilling to consider changing a given behavior in the foreseeable future; 2) contemplation, the stage that begins when the individual is thinking about changing a behavior, but is not taking active steps to change; 3) preparation, the stage during which the individual is making definite plans to change a given behavior; 4) action, the stage during which the individual initiates the behavior change by actively modifying habits or environment; and 5) maintenance, the stage during which the individual is sustaining the behavior change and preventing relapse. Individuals may cycle through the stages several times before they maintain a change in behavior (8). This theory has been used to assess and guide intervention programs for a variety of health behaviors, such as smoking cessation (9), exercise (10), and weight control (11). Although recently this theory has been used in cross-sectional studies to predict dietary fat intake among African-American women (12), only a few studies, such as the one by Greene and Rossi (13), have used this theory for intervention in dietary change, and none has staged specific dietary patterns in an attempt to tailor program content among African-American women. The purpose of this study was to evaluate the extent to which African-American women who participated in the EWLW reduced and maintained lower dietary fat intake in a 3-month follow-up period.
Procedures Participants in the EWLW were recruited individually through a social service agency that served as the programs sponsor and through advertisements in neighborhood newspapers that targeted African-American audiences. African-American women ages 2555 years and living in the neighborhoods were eligible for the study if they did not have diabetes, were not pregnant, and were >20% over ideal body weight, as determined by self-report (BMI >27). Eligible subjects were randomly assigned to a treatment or control group. Baseline data were collected before the intervention, at posttest intervals (immediately after the 3-month program), and at a 3-month follow-up assessment. The total study time period was 6 months. There was no further intervention during the posttreatment period for the treatment group. Participants in the control group did not receive any intervention during the treatment or follow-up phases, but were given a self-help workbook that reflected the content of the program and were offered a half-day workshop on healthy, low-fat eating after their follow-up assessment.
Description of program, integrity, and peer educator training The manual-based program consisted of six group sessions (approximately six to eight participants per group) and six individual sessions with a peer educator, integrated over the 3-month intervention phase. Participants met weekly with the peer educator. Each individual session focused on a dietary pattern that represented a way to reduce fat in the diet, including "avoid fat as seasoning," "substitution" of specially manufactured foods for higher fat counterparts, "modify meat" or removing fat and skin from meat, "avoid fried foods," and "replacement" or replacing high-fat foods with fruits, vegetables, grains, and bread. During the individual sessions, the peer educator assessed each participants stage or readiness to change each of the five dietary patterns, and then tailored the session content to that stage. The content of the six group sessions focused on specific skill areas that included the following: 1) "rate your plate" (participants learned how to assess the fat in their diet and target areas for change, 2) label reading (emphasizing portion size and the total fat and saturated fat content of food), 3) comparison shopping (emphasizing skills to purchase low-fat foods on a budget), 4) recipe modification (keeping culturally rich recipes in the diet while reducing fat content), 5) eating out (making healthy food choices in fast food and other restaurants), and 6) coping with high-risk situations. To assess program integrity, sessions were randomly audiotaped and scored by independent raters using detailed session checklists. Results of the process evaluation indicated that the peer educators delivered 91.42% of the content across 12 sessions and that the overall accuracy of information delivered was 88.52% (averaged across the three peer educators). The EWLW process evaluation methods and results are discussed in more detail elsewhere (16).
Variables
Dietary knowledge.
Label-reading knowledge.
Attitudes about diet and health.
Dietary patterns.
Readiness to change dietary patterns.
Fat and daily energy intake.
Height and weight.
Data analysis
Subject characteristics and participation
Readiness To Change Dietary Patterns Overall, participants in the treatment group reported a greater readiness to change their dietary patterns than those in the control group at the posttest assessment. Table 2 shows the percent of participants who reported being in the action stages (versus the pre-action stages) to perform each low-fat dietary pattern. 2 tests of the treatment effect, controlling for pretest scores via logistic regression, were significant for all dietary patterns. These significant differences were maintained at follow-up assessment.
Dietary knowledge and attitudes As shown in Table 3, between-group comparisons of the knowledge of fat in diet at the posttest assessment revealed that there was a significant difference between the treatment and control groups (F[2,289] = 58.38, P < 0.0001). The treatment group had significantly higher scores than the control group, after adjusting for the baseline scores. This difference remained significant at the 3-month follow-up assessment (F[2,290] = 76.26, P < 0.0001). Skill-based knowledge as measured by the Knowledge of Label Reading Questionnaire also showed significant differences between groups at the posttest assessment (F[2,290] = 141.71, P < 0.0001) and remained significant at the follow-up assessment (F[2,291] = 133.49, P < 0.0001). Comparisons of the participants attitudes about diet and health revealed that there were no significant differences between the treatment and control groups at the postintervention or 3-month follow-up assessments.
Actual dietary patterns The impact of the intervention indicated significant differences in the participants actual dietary behaviors (Table 3). Assessment of the participants dietary behaviors showed that the treatment group reported significantly more low-fat dietary patterns (total score) compared with the control group at the posttest (F[2,286] = 97.71, P < 0.0001) and follow-up assessments (F[2,290] = 57.38, P < 0.0001). Analyses of the separate dietary patterns were consistent with the results of the total scale, except for one pattern: there was no significant difference between the treatment and control groups in "replacement" at the posttreatment and follow-up assessments.
Dietary fat intake and weight Fat intake, as measured by the percent of calories from saturated fat, was also significantly reduced in the treatment group from pre- to posttest assessment (F[2,290] = 30.85, P < 0.0001). The post hoc t tests showed that the treatment group reported significantly less fat intake than the control group and that these differences were maintained at follow-up (F[2,291] = 25.59, P < 0.0001). The total daily energy intake of the treatment group was significantly lower than that of the control group from the pre- to posttest assessment (F[2,290] = 46.96, P < 0.0001) and at follow-up (F[2,291] = 30.75, P < 0.0001). Despite significant reductions in fat intake, results indicated that no significant group differences were detected in the weight and BMI of the participants.
This study addressed the following question: To what extent does a peer-led program that tailors content to participants readiness to make dietary changes reduce fat intake and increase low-fat dietary patterns, and maintain these changes over a follow-up phase? Other intermediate outcomes of interest included increasing skill-based knowledge (e.g., label reading) and knowledge and attitudes about dietary fat. The EWLW was evaluated using an experimental design with 3-month intervals between pre- and posttest assessments and posttest and follow-up assessments.
A critical finding in this study was that greater reductions were seen in fat intake of the EWLW group when compared with the control group and that the reductions were maintained at the 3-month follow-up assessment. At the posttest assessment, women in the EWLW condition had reduced their fat intake by 3.8% vs. 0.4% for the control group. At follow-up, fat intake remained significantly lower in the EWLW than in the control group (32.3 vs. 34.5%), which brought the former group closer to the public health goal of A second finding was the significant increases in low-fat dietary patterns among the EWLW group compared with the control group at posttest and follow-up assessments. It is likely that changes in dietary patterns led to the reduction of total fat intake. This was true across all dietary patterns except for "replacement" (replacing high-fat foods with fruits, vegetables, grains, and bread). Several explanations for why participants did not make significant changes in this dietary pattern are possible: 1) content on "replacement" was delivered in the 11th session (out of 12 sessions), and 38.7% did not receive the content on "replacement" because of attrition; 2) the program did not emphasize increasing intake of fiber (i.e., fruits and vegetables), but rather focused on reducing total fat; and 3) this pattern may involve a greater change in cuisine in that the replacement food looks and tastes different than the high-fat food. The data on increasing participants readiness to change dietary patterns is consistent with the above-mentioned findings on dietary patterns. A greater percentage of participants in the treatment group moved from pre-action to action stages across all dietary patterns, and maintained their significant gains at the follow-up assessment.
Intermediate outcomes, such as knowledge of fat in foods and reading and interpreting food labels, were increased and maintained for the participants in the treatment group when compared with the control group. Attitudinal change was not influenced by the intervention. This may be in part have been because of the low-to-fair reliability of the total attitudinal scale ( There was no significant weight loss among participants at the follow-up assessment. The reasons for the lack of weight loss are unclear. This finding may be attributable to measurement problems associated with dietary assessment. Specifically, it is possible that the women in both conditions, either through social desirability or difficulty in recalling intake over the previous month, underreported their intake. However, there was consistency in underreporting across pre- and posttest and follow-up assessments and across conditions, which lends some support to the suggestion that the differences between groups may have been real. It is important to note that the objective of the EWLW was not to lower caloric intake but to lower fat intake and change dietary patterns, a recognized strategy for reducing the risk of diabetes (5,6). This focus, which proved effective, was culturally appropriate, as African-American women are not generally as concerned about weight loss as their Caucasian counterparts (2224). Also, changing dietary patterns may be a first step toward other diabetes risk-reduction strategies, as successful attainment of more immediate goals holds relevance as a motivating factor for more long-term prevention goals (e.g., maintaining weight loss). Finally, these findings do not negate the importance of weight reduction in diabetes prevention, but rather suggest what strategies might work for certain outcomes in this population. Reduction in fat intake alone does not necessarily result in a reduction of weight. Future programs that emphasize increases in fiber (fruits and vegetables) and physical activity, in addition to decreases in fat intake, may be more effective in decreasing weight and BMI than the EWLW. In conclusion, the gathered data indicated that a stage-based intervention conducted by trained peer leaders in the community is effective in changing dietary patterns and reducing fat intake among low-income African-American women. The EWLW program uses strategies that could be expanded to include a greater emphasis on physical activity and increased fiber intake. A peer-led approach with the collaboration of a community organization that is located in the target neighborhoods holds promise for reducing the risk of diabetes among lower-income African-American women.
This work was supported by grant no. RO1-DK-48143 from the National Institutes of Diabetes and Digestive and Kidney Diseases, and the Office of Research on Minority Health of the National Institutes of Health to the George Warren Brown School of Social Work of Washington University. We would like to thank the following individuals for their contribution to this project: the staff of the Wellness Initiative of Grace Hill Neighborhood Services; Hope Krebill, BSN, RN; and Alan Kristal, PhD.
Address correspondence and reprint requests to Wendy Auslander, PhD, George Warren Brown School of Social Work, Washington University, Campus Box 1196, St. Louis, MO 63130. E-mail: wendyaus{at}gwbmail.wustl.edu. Received for publication 25 October 2001 and accepted in revised form 31 January 2002. A table elsewhere in this issue shows conventional and Système International (SI) units and conversion factors for many substances.
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