Isobel R. Contento

Review and Analysis of Evaluation Measures Used in Nutrition Education Intervention Research

The purpose of this review is to provide a summary of the kinds of evaluation measures used in 265 nutrition education intervention studies conducted between 1980 and 1999 and an analysis of psychometric issues arising from such a review. The data are summarized in terms of tables for interventions with each of six key population groups: preschool children, school-aged children, adults, pregnant women and breast-feeding promotion, older adults, and inservice preparation of professionals and paraprofessionals. Measures evaluating knowledge and skills or behavioral capabilities were most widely used in studies with preschool, school-aged, and inservice populations (50%-85%) and less widely used in studies with the other groups, particularly breast-feeding promotion (5%). Measures of potential psychosocial mediators or correlates of behavior such as outcome expectancies, self-efficacy, or behavioral intention were used in 90% of behaviorally focused studies with school-aged children and in about 20% of studies with adults. Dietary intake measures were used in almost all studies, primarily food recalls, records, and quantitative food frequency questionnaires. Short frequency instruments involving only foods targeted in the intervention such as fruits and vegetables are increasingly being used. Measures of specific observable behaviors are also increasingly being used. Physiologic parameters were used in about 33% of behaviorally focused interventions with school-aged children and adults, 20% with older adults, and 65% with pregnant women and/or their infants. Criterion validity of newly developed intake instruments and content validity of instruments measuring mediating variables were reported in the majority (range 50%-90%) of studies. Reliability and stability of measures of mediating variables were reported in 50% to 75% of studies, with reliability coefficients mostly about .6 to .7. Two major conclusions from this review are that evaluation measures should be appropriate to the purpose, duration, and power of the intervention and that measures should have adequate validity and reliability in relation to both the outcomes and characteristics of the target audience. Major implications are that considerable preliminary work needs to be done before any intervention study to develop and test evaluation instruments so that they are appropriate and have adequate psychometric properties, and cognitive testing of published instruments with each new target audience is essential. We will then be better able to make judgments about the effectiveness of nutrition education.

Resting metabolic rate and energy balance in amenorrheic and eumenorrheic runners

This study investigated metabolic and nutritional factors in association with athletic menstrual dysfunction (AMD). Three groups of women were studied: amenorrheic runners (amenorrheic), eumenorrheic runners (eumenorrheic), and eumenorrheic sedentary controls (sedentary). Amenorrheic and eumenorrheic were similar in age, weight, percent body fat by hydrodensitometry, training pace and mileage, best 10 km race time, years running, and maximal oxygen consumption. When adjusted for body weight or for fat-free mass by analysis of covariance, RMR was significantly lower in amenorrheic than in eumenorrheic and sedentary. The daily caloric intakes of the groups did not differ significantly, but the amenorrheic scored significantly higher than the eumenorrheic and sedentary on a scale of aberrant eating patterns. Amenorrheic high mileage runners seem to have a less adequate diet than eumenorrheic runners but appear to maintain energy balance and stable weight through a reduction in RMR.

Food Label Use and Its Relation to Dietary Intake among US Adults

Rates of diet-related chronic disease combined with the lack of current data on patterns of food label use by the US population warrant re-examination of the use and potential influence of this public health tool. The purpose of this study was to describe the prevalence of food label use and the association between food label use and nutrient intake in a nationally representative sample of US adults who participated in the 2005-2006 National Health and Nutrition Examination Survey. Data on food label use were collected during the interview portion of the survey, and nutrient intake was estimated using the average of two 24-hour dietary recalls. In this sample, 61.6% of participants reported using the Nutrition Facts panel, 51.6% looked at the list of ingredients, 47.2% looked at serving size, and 43.8% reviewed health claims at least sometimes when deciding to purchase a food product. There were significant differences (P<0.05) in food label use across all demographic characteristics examined. Significant differences (P<0.05) in mean nutrient intake of total energy, total fat, saturated fat, cholesterol, sodium, dietary fiber, and sugars were observed between food label users and non-users with label users reporting healthier nutrient consumption. The greatest differences observed were for total energy and fat and for use of specific nutrient information on the food label. Despite food label use being associated with improved dietary factors, label use alone is not expected to be sufficient in modifying behavior ultimately leading to improved health outcomes.

Research perspective on school-based nutrition education

Abstract This review examined the major school-based nutrition education research studies conducted during the decade of the 1980s. General nutrition education studies were based primarily on a knowledge-attitude-behavior approach, while disease reduction/health enhancement studies were behaviorally oriented and generally based on social learning theory. Research designs and methodologies have been greatly improved, compared with previous reviews. A major finding was that most studies involved only 10-15 hours of instruction over a 3-15 week period. These short studies resulted in a positive effect on cognitive outcomes such as nutrition knowledge, diet-related skills, behavioral expectations, and self-efficacy. The effect on attitudes was inconsistent but generally positive. The impact of general nutrition education programs on behavior was minimal. The impact of the more specifically targeted behavioral programs was slightly more positive but still inconsistent. Programs that were several years in duration resulted in changes in dietary intakes and physiological parameters. Teacher preparation increased the time spent on nutrition education. Parent involvement enhanced classroom instruction for younger children, particularly when it was of sufficient intensity and duration. The educational impact of modifying school lunch menus has received little study. Implications for practice and research are discussed.

Body Image, Weight, and Food Choices of Latina Women and Their Young Children

OBJECTIVE To investigate body image perceptions of women about themselves and their young children and their relationship to their food choices and those of their children. DESIGN Descriptive and correlational study. PARTICIPANTS AND SETTING 187 low-income, Latina women and their children, ages 5 to 7 years and 52% female, in New York City. VARIABLES MEASURED Body image, food frequency, body mass index (BMI) of mothers and children, and food choice criteria of mothers for their children. ANALYSIS Descriptive statistics and correlations. RESULTS All of the women selected a relatively thin body image as the most desirable, attractive, fit, and healthy (about 2.5 on a scale of 1-7). Body size dissatisfaction or wish to be thinner was significantly associated with more healthful diets. Tertiles (thirds) of children at the 50th and 75th mean BMI-for-age percentiles were thought to be too thin to be attractive or healthy and the third of children with a mean above the 97th percentile only barely too large. Mothers with the highest body mass indices may make the least healthful choices for their children. CONCLUSIONS AND IMPLICATIONS These Latina women preferred a thin figure for themselves but a plumper figure for their children. Culturally competent nutrition education incorporating body image issues needs to assist mothers in understanding the health consequences of childhood obesity, recognizing when their children are overweight, and understanding the importance of healthful food choices for their children.

The Cookshop Program: Outcome Evaluation of a Nutrition Education Program Linking Lunchroom Food Experiences with Classroom Cooking Experiences

Abstract The purpose of this study was to examine the feasibility and effectiveness of a nutrition education intervention for elementary school children, grades K–6, called the Cookshop Program. It was designed to increase preferences for and consumption of minimally processed whole grains and vegetables through cooking these foods in the classroom along with multiple exposures to the same foods in the cafeteria and parent involvement. It emphasized how eating a plant-based diet was not only important for personal health but was also resource conserving or more ecologically sustainable. This outcome evaluation study compared cooking as an educational strategy with the more usual active participatory educational methods. The study used a quasi-experimental, pre/post intervention-comparison group design with 39 classes (590 students) assigned approximately equally, through matching, to four conditions: cookshops plus food and environment lessons (CS + FEL), cookshops only (CS), food and environment lessons only (FEL), and comparison condition (Com), receiving neither cookshops nor lessons. Data were analyzed using a 2 x 2 factorial design using analysis of covariance. Class was the unit of analysis. Main positive effects were obtained for CS on preferences, knowledge, and plate waste in both younger and older children and on behavioral intention in younger children and cooking self-efficacy in older children. Main positive effects were obtained for FEL in knowledge for both age groups. The results suggest that actual cooking experiences and eating food with peers, accompanied by cognitive learning, may provide a promising approach to nutrition education, especially for younger children. Lack of random assignment of classes to conditions was a limitation of the study. Further research is needed to evaluate this approach using randomized designs.

Application of the transtheoretical model to fruit and vegetable consumption among economically disadvantaged African-American adolescents: preliminary findings.

Purpose. To examine the application of the transtheoretical model (TTM) to fruit and vegetable consumption among economically disadvantaged African-American adolescents. Methods. Scales for measuring decisional balance, situational self-efficacy, and processes of change for fruit and vegetable consumption were developed and pretested with 57 economically disadvantaged African-American adolescents. The scales and measures for assessing stages of change, demographic variables, and fruit and vegetable consumption were administered to a separate sample of 262 participants. t-tests for independent samples and analysis of variance were used to examine differences in TTM variables and fruit and vegetable consumption across stages of change. Results. Two-factor solutions for decisional balance and processes of change and a three-factor solution for situational self-efficacy provided the best fit to the data. Alpha coefficients of reliability for the scales ranged from .77 (experiential change processes) to .91 (pros). Participants in action-maintenance stages evidenced higher pros, self-efficacy, and fruit and vegetable consumption and significantly lower cons than did participants in precontemplation and contemplation-preparation stages. Also, participants in action-maintenance stages used processes of change more frequently than did those in precontemplation-contemplation-preparation stages. The use of experiential and behavioral processes within these stages did not differ significantly, as posited. Discussion. Observed differences in TTM variables and fruit and vegetable consumption by stage of change in this sample of economically disadvantaged African-American adolescents were consistent with theory and previous applications of the model to fruit and vegetable consumption in adults. With replication studies, the TTM may be appropriate for designing interventions to increase fruit and vegetable consumption among this population.

Stages of change in dietary fat reduction: Social psychological correlates

Abstract This paper describes the application of the stages-of-change construct to fat intake by examining the association of social psychological variables with stages of change based on dietary fat reduction. The association of stages of change with motivational beliefs, social influence, and self-efficacy variables derived from social psychological theories and with fat intake was assessed in 615 adults. Results indicated that stage assignment of individuals by a short self-report staging instrument was corroborated by their fat intake data and that dietary stage groups differed significantly on most variables in ways predicted by theory. ANOVA and discriminant analyses showed that variables reflecting a state of psychological readiness to change and cues to action were more strongly associated with contemplation of change. Reduction of perceived barriers, mostly in terms of taste and perceived difficulty of performing needed behaviors, and increased overall health concern, social modeling, and self-effcacy were associated with taking action and maintaining the behavior change.

Adolescents Demonstrate Improvement in Obesity Risk Behaviors after Completion of Choice, Control & Change, a Curriculum Addressing Personal Agency and Autonomous Motivation

BACKGROUND The rapid increase of obesity and diabetes risk beginning in youth, particularly those from disadvantaged communities, calls for prevention efforts. OBJECTIVE To examine the impact of a curriculum intervention, Choice, Control & Change, on the adoption of the energy balance-related behaviors of decreasing sweetened drinks, packaged snacks, fast food, and leisure screen time, and increasing water, fruits and vegetables, and physical activity, and on potential psychosocial mediators of the behaviors. DESIGN Ten middle schools were randomly assigned within matched pairs to either intervention or comparison/delayed control conditions during the 2006-2007 school year. SUBJECTS/SETTING Students were from low-income New York City neighborhoods; 562 were in the intervention condition, and 574 in the comparison condition. INTERVENTION Students received the 24 Choice, Control & Change lessons that used science inquiry investigations to enhance motivation for action, and social cognitive and self-determination theories to increase personal agency and autonomous motivation to take action. MAIN OUTCOME MEASURES Self-report instruments to measure energy balance-related behaviors targeted by the curriculum and potential psychosocial mediators of the behaviors. STATISTICAL ANALYSES Analysis of covariance with group (intervention/control) as a fixed factor and pretest as covariate. RESULTS Students in intervention schools compared to the delayed intervention controls reported consumption of considerably fewer sweetened drinks and packaged snacks, smaller sizes of fast food, increased intentional walking for exercise, and decreased leisure screen time, but showed no increases in their intakes of water, fruits, and vegetables. They showed substantial increases in positive outcome expectations about the behaviors, self-efficacy, goal intentions, competence, and autonomy. CONCLUSIONS The Choice, Control & Change curriculum was effective in improving many of the specifically targeted behaviors related to reducing obesity risk, indicating that combining inquiry-based science education and behavioral theory is a promising approach.

Food choice and diet variety in weight-restored patients with anorexia nervosa.

Anorexia nervosa is a serious psychiatric illness associated with substantial morbidity and mortality. Weight-restored females with anorexia nervosa with limited diet variety, assessed by a diet variety score, have been reported to have poor outcomes. Using the same patient cohort, the objective of the current study was to provide a detailed description of the types of foods from which patients restrict variety in their diets. Forty-one weight-restored patients, hospitalized between June 2000 and July 2005, who completed a 4-day food record before discharge were followed for up to 1 year. Patient outcomes were categorized as a success (n=29) or failure (n=12) using Morgan-Russell criteria. Although the total number of foods selected did not differ between the success and failure groups (73±14 vs 74±13, respectively; P=0.741), a significant difference in the total number of different foods was observed: the failure group selected fewer and the success group selected more (43±9 vs 51±7; P=0.005). Outcomes groups also differed significantly in the variety of foods selected from 5 of 17 food groups. Results suggest that a diet limited in total variety and specifically limited in variety from five food groups may be associated with relapse in patients with anorexia nervosa.