The average adult has a poor quality diet and sedentary lifestyle, but the best way to produce sustained healthy change remains unknown. The MBC2 intervention uses handheld technology to help individuals monitor and transmit information about their eating and activity remotely to a behavior coach. The proposed trial tests whether MBC2 intervention improves diet and activity more than a stress management control condition, and whether changing multiple health behaviors is best achieved by changing them all at the same time, or one after another.
Poor quality diet and physical inactivity are the most prevalent, preventable causes of death in the United States. In particular, high saturated fat diet (Fat), low fruit and vegetable intake (FV), low physical activity (PA), and high sedentary leisure screen time (Sed) co-occur and heighten the risks of cardiovascular disease and cancers. The first Make Better Choices (MBC1) experiment contrasted four strategies to promote healthful change across these four risk behaviors. Each intervention targeted two behaviors (one diet, one activity) simultaneously and either increased healthy or decreased unhealthy responding. The intervention targeting increased FV and decreased Sed was most efficacious, yielding unexpectedly sustained improvement in three out of the four risk behaviors (FV, Sed, Fat). The proposed MBC2 trial tests the efficacy of MBC intervention to promote sustained, healthful change in diet and activity at 6 and 12 months, as contrasted with a stress management control condition. MBC2 tests competing hypotheses about the optimal way to increase PA without undermining the maintenance of FV, Sed, and Fat by changing multiple behaviors either sequentially or simultaneously. Furthermore, MBC2 examines mediators and biomarkers of healthy lifestyle change. Community dwelling adults (N=250) with suboptimal diet and inactive lifestyle will be randomized to the following conditions: 1) Sequential MBC (increasing FV intake and decreasing Sed, followed by increasing PA), 2) Simultaneous MBC (increasing FV, decreasing Sed, and increasing PA), or 3) Control (stress management). Participants in all conditions will use Smartphones equipped with customized behavioral decision support tools to self-monitor health behaviors. These handheld devices will be programmed to automatically transmit these data to our study server to be reviewed by a personal behavior coach. Based on theories of self-regulation and habit strength, the Mastery hypothesis predicts superior health behavior change for participants randomized to the sequential condition. It is anticipated that these effects will be mediated by greater habit strength for healthy eating and physical activity. However, based on goal systems theory, the Synergy hypothesis predicts superior health behavior change among participants randomized to the simultaneous condition. It is anticipated that these effects will be mediated by the establishment of superordinate healthy lifestyle goals. The results of the MBC2 trial will assist researchers in understanding the optimal manner in which to facilitate multiple health behavior change in this population. Furthermore, these data will help to identify the mechanisms that underlie healthy change among prevalent risk behaviors. If successful, this trial will also result in an innovative, highly disseminable technology-supported minimal counseling intervention to address the American unhealthy diet and sedentary lifestyle.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
SINGLE
Enrollment
212
Participants in the sequential condition will increase F/V consumption and decrease Sed behavior (weeks 1-6), then increase physical activity (weeks 7-12). Smartphones are equipped with customized real-time goal thermometers that provide objective feedback on target behaviors (FV, Sed, and PA). At the start of prescription, the FV and Sed goal thermometers are activated. During week 1-2, participants will close 1/3 of the gap between their baseline behaviors and target behaviors. During week 3-4 they will close 2/3 of the gap, and in weeks 5-6 they will achieve 100% of their goals. Participants will maintain these goals for the remainder of the 12-week intervention. At week 7, a real-time PA goal thermometer wirelessly linked to accelerometers will be activated. Similarly, in weeks 7-8 participants will be asked to close 1/3 of the gap between their baseline PA and target, in week 9-10 they will close 2/3 of the gap, and finally they will reach 100% of their PA goal in weeks 11-12.
Simultaneous MBC condition will target FV+, Sed- and PA+ simultaneously. Participants in the simultaneous condition will wear their accelerometers and enter diet and sedentary activity 5 days/week. All 3 goal thermometers will be activated from the outset of prescription. The goal will be to close 1/3 of the gap between their FV, Sed, and PA statuses and the targets in weeks 1-2, close 2/3 of the gap in weeks 3-4, reach their targets in weeks 5-6, and then maintain target level behavior changes for FV, Sed and PA through week 12.
Northwestern University-Feinberg School of Medicine
Chicago, Illinois, United States
Change in Fruit/Vegetable Serving Intake
Change from baseline in standard fruit/vegetable serving intake measured at 3, 6, and 9 months.
Time frame: 3, 6, and 9 months
Change in Saturated Fat (% of daily calories from fat) Intake
Change from baseline in saturated fat intake (assessed by % of daily calories from fat) at 3, 6, 9-months.
Time frame: 3, 6, and 9-months
Change in Sedentary Leisure Screen Time (minutes/week)
Change from baseline in minutes per week of sedentary leisure screen time (e.g., TV watching, recreational computer use) at 3, 6, and 9-months.
Time frame: 3, 6, and 9-months
Change in Physical Activity (minutes/week)
Change from baseline in minutes per week of physical activity measured by accelerometer at 3, 6, and 9-months.
Time frame: 3, 6, and 9-months
Change in Dietary Intake
Change from baseline in dietary consumption (e.g., fruits/vegetables) measured by clinician administered dietary recall (Block Food Frequency Questionnaire) at 3 and 9-months. This standardized measure will be used to validate the self-report data.
Time frame: 3 and 9-months
Healthy Diet and Activity Improvement
Healthy diet and activity improvement standardized to a common z score metric and aggregated across changes in fruit and vegetable intake, saturated fat intake, sedentary leisure screen time, and physical activity
Time frame: 3, 6, and 9 months
Change in Blood Pressure (mmHg)
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Participants in the stress management control condition target stress, relaxation and sleep. This will serve as an attentional control condition. During the 12-week prescription period, participants will wear accelerometers, log hours slept, enter real-time information about their relaxation exercises and stress, and monitor 3 goal thermometers (sleep, relaxation, stress) to meet behavioral targets. Similarly, their goal is to close 1/3 of the gap between their baseline stress, sleep, and performance of relaxation exercises and the target criterion in weeks 1-2, close 2/3 of the gap in weeks 3-4, reach their targets in weeks 5-6, and then maintain these behavior changes through week 12.
Change from baseline in blood pressure measured in mmHg according to the CARDIA protocol.
Time frame: 3 and 9-months
Change in Lipids
Change from baseline in lipids (total cholesterol, triglycerides, HDL-C, calculated LDL-C) assayed following antecubital venipuncture
Time frame: 3 and 9-months
Change in Insulin (mg/dL)
Change from baseline in insulin measured in mg/dL via immunoassay following antecubital venipuncture at 3 and 9-months.
Time frame: 3 and 9-months
Change in Weight (kg)
Change from baseline in body weight in kg measured using calibrated beam balance scale at 3 and 9-months.
Time frame: 3 and 9-months
Change in Waist circumference (cm)
Change from baseline in waist circumference measured in cm (repeated twice, then averaged) at 3 and 9-months.
Time frame: 3 and 9-months
Change in Quality of Life
Change from baseline in quality of life measured by the SF-36 self-report questionnaire at 3 and 9-months.
Time frame: 3 and 9-months