Susan M. Schembre

Impact of an online healthful eating and physical activity program for college students.

Purpose. To identify impact of an online nutrition and physical activity program for college students. Design. Randomized, controlled trial using online questionnaires and on-site physical and fitness assessments with measurement intervals of 0 (baseline), 3 (postintervention), and 15 months (follow-up). Setting. Online intervention delivered to college students; a centralized Web site was used for recruitment, data collection, data management, and intervention delivery. Subjects. College students (18–24 years old, n = 1689), from eight universities (Michigan State University, South Dakota State University, Syracuse University, The Pennsylvania State University, Tuskegee University, University of Rhode Island, University of Maine, and University of Wisconsin). Intervention. A 10-lesson curriculum focusing on healthful eating and physical activity, stressing nondieting principles such as size acceptance and eating competence (software developer: Rainstorm, Inc, Orono, Maine). Measures. Measurements included anthropometrics, cardiorespiratory fitness, fruit/vegetable (FV) intake, eating competence, physical activity, and psychosocial stress. Analysis. Repeated measures analysis of variance for outcome variables. Results. Most subjects were white, undergraduate females (63%), with 25% either overweight or obese. Treatment group completion rate for the curriculum was 84%. Over 15 months, the treatment group had significantly higher FV intake (+.5 cups/d) and physical activity participation (+270 metabolic equivalent minutes per week) than controls. For both groups, anthropometric values and stress increased, and fitness levels decreased. Gender differences were present for most variables. First-year males and females gained more weight than participants in other school years. Conclusion. A 10-week online nutrition and physical activity intervention to encourage competence in making healthful food and eating decisions had a positive, lasting effect on FV intake and maintained baseline levels of physical activity in a population that otherwise experiences significant declines in these healthful behaviors.

Development and validation of a weight-related eating questionnaire

The objective of this study was to develop an improved weight-related eating questionnaire (WREQ) that reflects recent advancements in the assessment and understanding of theory-based eating behaviors. A sequential process of measurement development was used to construct this brief but comprehensive questionnaire. By factor analysis and structural equation modeling, a 16-item, four-factor structure was found to best fit the data. This newly developed questionnaire measures two constructs of dietary restraint (routine and compensatory restraint), susceptibility to external cues (external eating), and emotional eating. The WREQ demonstrated good preliminary construct validation against similar psychometrics, BMI, and measures of fruit and vegetable and dietary fat intake. Further validation analyses, particularly against other energy intake measures, are justified. Successful development and preliminary validation of this updated weight-related eating behavior questionnaire provides support for the WREQ as an improvement over existing eating behavior measures and warrants its use in future research.

Process Evaluation of Project WebHealth: A Nondieting Web-based Intervention for Obesity Prevention in College Students

OBJECTIVE To evaluate the motivational effect of the Project WebHealth study procedures and intervention components on weight-related health behavior changes in male and female college students. DESIGN Process evaluation. SETTING Eight universities in the United States. PARTICIPANTS Project WebHealth participants (n = 653; 29% men). MAIN OUTCOME MEASURES Participants rated motivational effects of study procedures and intervention components. Participants were grouped into outcome-based health behavior categories based on achievement of desired targets for fruit and vegetable intake, physical activity, and/or body weight. ANALYSIS Differences in motivation from each procedure and component were analyzed by gender- and outcome-based health behavior category. RESULTS Women were generally more motivated than men. Compared to those who did not meet any target health behaviors, men with improved health outcomes (68%) were significantly more motivated by the skills to fuel the body lesson, goal setting, and research snippets. Their female counterparts (63%) were significantly more motivated by the lessons on body size and eating enjoyment, and by the suggested weekly activities. CONCLUSIONS AND IMPLICATIONS Specific study procedures and components of Project WebHealth motivated study participants to improve their weight-related health behaviors, and they differed by gender. Findings support the need for gender-tailored interventions in this population.

Project TwEATs. A feasibility study testing the use of automated text messaging to monitor appetite ratings in a free-living population.

There are no standardized methods for monitoring appetite in free-living populations. Fifteen participants tested a computer-automated text-messaging system designed to track hunger ratings over seven days. Participants were sent text-messages (SMS) hourly and instructed to reply during waking hours with their current hunger rating. Of 168 SMS, 0.6-7.1% were undelivered, varying by mobile service provider. On average 12 SMS responses were received daily with minor variations by observation day or day of the week. Compliance was over 74%, and 93% of the ratings were received within 30-min. Automated text-messaging is a feasible method to monitor appetite ratings in this population.

Eating breakfast more frequently is cross-sectionally associated with greater physical activity and lower levels of adiposity in overweight Latina and African American girls

BACKGROUND Eating breakfast is believed to promote a healthy body weight. Yet, few studies have examined the contribution of energy balance-related behavioral factors to this relation in minority youth. OBJECTIVE We assessed the associations between breakfast consumption and dietary intake, physical activity (PA), and adiposity before and after accounting for energy intake and PA in minority girls. DESIGN Cross-sectional data were obtained on body mass index (BMI), percentage body fat (measured by BodPod), dietary intake (measured with 3-d dietary records), and PA (measured with 7-d accelerometry) from 87 Latina and African American girls 8-17 y of age (75% Latina, 80% overweight). Dietary records were used to categorize girls as more frequent breakfast eaters (MF; 2 or 3 of 3 d; n = 57) or less frequent breakfast eaters (LF; 0 or 1 of 3 d; n = 30). Chi-square tests, ANCOVA, and multiple regression analyses were conducted. Mediation was assessed with a Sobel test. RESULTS Compared with the MF group, the LF group spent 30% less time (12.6 min/d) in moderate-to-vigorous-intensity PA (MVPA; P = 0.004) and had a higher percentage body fat (P = 0.029). MVPA accounted for 25% (95% CI: -8.8%, 58.1%; P = 0.139) of the relation between breakfast consumption and percentage body fat. We were unable to show that energy intake or MVPA was a significant mediator of the relation between breakfast consumption and adiposity in this sample. CONCLUSIONS Evidence suggests that among predominantly overweight minority girls, MVPA, but not energy intake, was associated with both breakfast consumption and adiposity; however, a lack of power reduced our ability to detect a significant mediation effect. Other unobserved variables likely contribute to this relation.

Does the Transtheoretical Model of Behavior Change Provide a Useful Basis for Interventions to Promote Fruit and Vegetable Consumption

Purpose. To determine whether Transtheoretical Model (TTM) constructs differ between individuals making successful versus unsuccessful stage transitions for consumption of five or more servings of fruit and vegetables each day and thus provide a useful basis for designing health promotion interventions. Design. Longitudinal, observational study. A randomly selected, multiethnic cohort of adults assessed at 6-month intervals over 2 years. Setting. General community, Hawaii. Subjects. There were 700 participants (62.6% female; mean = 47 ± 17.1 years; 31.1% Asian, 22.1% Native Hawaiian/Pacific Islander, 35.0% Caucasian; 25.1% participation rate). Measures. Stage of readiness, experiential and behavioral processes of change, pros, cons, self-efficacy, and self-reported fruit and vegetable consumption. Analysis. The study used t-tests to determine which TTM variable scores differed consistently between those making “successful” versus “unsuccessful” stage transitions from precontemplation, preparation, and maintenance. Sample sizes for contemplation and action prohibited similar analyses. Results. Compared to those remaining in precontemplation, individuals successfully progressing from precontemplation showed significantly greater use of behavioral processes (collectively and self-liberation) and consciousness raising (p < .001). However, only self-liberation demonstrated significant differences consistently over time. Conclusion. This longitudinal investigation reveals that TTM behavioral processes, particularly self-liberation, predict successful transition out of precontemplation for adult fruit and vegetable consumption, suggesting that public health messages tailored according to these TTM variables may be effective for this group. However, for adults prepared to adopt or maintain fruit and vegetable consumption, tailoring based on variables from other theories is needed.

Non-exercise estimation of VO2max using the international physical activity questionnaire

Non-exercise equations developed from self-reported physical activity can estimate maximal oxygen uptake (VO2max) as well as sub-maximal exercise testing. The International Physical Activity Questionnaire is the most widely used and validated self-report measure of physical activity. This study aimed to develop and test a VO2max estimation equation derived from the International Physical Activity Questionnaire–Short Form. College-aged males and females (n = 80) completed the International Physical Activity Questionnaire–Short Form and performed a maximal exercise test. The estimation equation was created with multivariate regression in a gender-balanced subsample of participants, equally representing five levels of fitness (n = 50) and validated in the remaining participants (n = 30). The resulting equation explained 43% of the variance in measured VO2max (standard error of estimate = 5.45 ml·kg–1·min–1). Estimated VO2max for 87% of individuals fell within acceptable limits of error observed with sub-maximal exercise testing (20% error). The International Physical Activity Questionnaire–Short Form can be used to successfully estimate VO2max as well as sub-maximal exercise tests. Development of other population-specific estimation equations is warranted.

Effectiveness of lifestyle interventions to reduce binge eating symptoms in African American and Hispanic women

OBJECTIVE Lifestyle interventions that promote physical activity and healthy dietary habits may reduce binge eating symptoms and be more feasible and sustainable among ethnic minority women, who are less likely to seek clinical treatment for eating disorders. The purpose of this study was to investigate (1) whether participating in a lifestyle intervention is a feasible way to decrease binge eating symptoms (BES) and (2) whether changes in BES differed by intervention (physical activity vs. dietary habits) and binge eating status at baseline (binger eater vs. non-binge eater) in African American and Hispanic women. METHOD Health Is Power (HIP) was a longitudinal randomized controlled trial to promote physical activity and improve dietary habits. Women (N = 180) who completed anthropometric measures and questionnaires assessing fruit and vegetable and dietary fat intake, BES and demographics at baseline and post-intervention six months later were included in the current study. RESULTS Over one-fourth (27.8%) of participants were categorized as binge-eaters. Repeated measures ANOVA demonstrated significant two- and three-way interactions. Decreases in BES over time were greater in binge eaters than in non-binge eaters (F(1,164) = 33.253, p < .001), and women classified as binge eaters who participated in the physical activity intervention reported greater decreases in BES than non-binge eaters in the dietary habits intervention (F(1,157) = 5.170, p = .024). DISCUSSION Findings suggest behavioral interventions to increase physical activity may lead to reductions in BES among ethnic minority women and ultimately reduce the prevalence of binge eating disorder and health disparities in this population.

The time-varying association between perceived stress and hunger within and between days

OBJECTIVE Examine the association between perceived stress and hunger continuously over a week in free-living individuals. METHODS Forty five young adults (70% women, 30% overweight/obese) ages 18 to 24 years (Mean = 20.7, SD = 1.5), with BMI between 17.4 and 36.3 kg/m(2) (Mean = 23.6, SD = 4.0) provided between 513 and 577 concurrent ratings of perceived stress and hunger for 7 days via hourly, text messaging assessments and real-time eating records. Time-varying effect modeling was used to explore whether the within-day fluctuations in stress are related to perceived hunger assessed on a momentary basis. RESULTS A generally positive stress-hunger relationship was confirmed, but we found that the strength of the relationship was not linear. Rather, the magnitude of the association between perceived stress and hunger changed throughout the day such that only during specific time intervals were stress and hunger significantly related. Specifically, the strength of the positive association peaked during late afternoon hours on weekdays (β = 0.31, p < .05) and it peaked during evening hours on weekend days (β = 0.56, p < .05). CONCLUSION This is the first empirical study to demonstrate potentially maladaptive, nonlinear stress-hunger associations that peak in the afternoon or evening hours. While we are unable to infer causality from these analyses, our findings provide empirical evidence for a potentially high-risk time of day for stress-induced eating. Replication of these findings in larger, more diverse samples will aid with the design and implementation of real-time intervention studies aimed at reducing stress-eating.

Beyond Cue Reactivity: Non-Drug-Related Motivationally Relevant Stimuli Are Necessary to Understand Reactivity to Drug-Related Cues

Neurobiological models of addiction posit that drug use can alter reward processes in two ways: (1) by increasing the motivational relevance of drugs and drug-related cues and (2) by reducing the motivational relevance of non-drug-related rewards. Here, we discuss the results from a series of neuroimaging studies in which we assessed the extent to which these hypotheses apply to nicotine dependence. In these studies, we recorded smokers’ and nonsmokers’ brain responses to a wide array of motivationally relevant visual stimuli that included pleasant, unpleasant, cigarette-related, and neutral images. Based on these findings, we highlight the flaws of the traditional cue reactivity paradigm and we conclude that responses to non-drug-related motivationally relevant stimuli should be used to appropriately gauge the motivational relevance of cigarette-related cues and to identify smokers attributing higher motivational relevance to drug-related cues than to non-drug-related rewards. Identifying these individuals is clinically relevant as they achieve lower rates of long-term smoking abstinence when attempting to quit. Finally, we show how this approach may be extended beyond nicotine dependence to inform theoretical and clinical research in the study of obesity. Implications The cue reactivity paradigm (ie, comparing responses evoked by drug-related cues to those evoked by neutral cues) cannot provide conclusive information about the motivational relevance of drug-related cues. Responses to non-drug-related motivationally relevant stimuli should be used to appropriately gauge the level of motivational relevance that substance-dependent individuals attribute to drug-related cues.