Just-in-Time Feedback in Diet and Physical Activity Interventions: Systematic Review and Practical Design Framework.

BACKGROUND: The integration of body-worn sensors with mobile devices presents a tremendous opportunity to improve just-in-time behavioral interventions by enhancing bidirectional communication between investigators and their participants. This approach can be used to deliver supportive feedback at critical moments to optimize the attainment of health behavior goals. OBJECTIVE: The goals of this systematic review were to summarize data on the content characteristics of feedback messaging used in diet and physical activity (PA) interventions and to develop a practical framework for designing just-in-time feedback for behavioral interventions. METHODS: Interventions that included just-in-time feedback on PA, sedentary behavior, or dietary intake were eligible for inclusion. Feedback content and efficacy data were synthesized descriptively. RESULTS: The review included 31 studies (15/31, 48%, targeting PA or sedentary behavior only; 13/31, 42%, targeting diet and PA; and 3/31, 10%, targeting diet only). All studies used just-in-time feedback, 30 (97%, 30/31) used personalized feedback, and 24 (78%, 24/31) used goal-oriented feedback, but only 5 (16%, 5/31) used actionable feedback. Of the 9 studies that tested the efficacy of providing feedback to promote behavior change, 4 reported significant improvements in health behavior. In 3 of these 4 studies, feedback was continuously available, goal-oriented, or actionable. CONCLUSIONS: Feedback that was continuously available, personalized, and actionable relative to a known behavioral objective was prominent in intervention studies with significant behavior change outcomes. Future research should determine whether all or some of these characteristics are needed to optimize the effect of feedback in just-in-time interventions.

Ecological Momentary Assessment in Physical Activity Research.

Theories explaining why individuals participate in physical activity often do not take into account within-person variation or dynamic patterns of change. Time-intensive methods such as Ecological Momentary Assessment are more conducive to capturing time- and spatially-varying explanatory factors and intraindividual fluctuations than traditional methods and thus may yield new insights into the prediction and modeling of physical activity behavior.

REAL-TIME SUBJECTIVE ASSESSMENT OF PSYCHOLOGICAL STRESS: ASSOCIATIONS WITH OBJECTIVELY-MEASURED PHYSICAL ACTIVITY LEVELS.

Psychosocial stress may be a factor in the link between physical activity and obesity. This study examines how the daily experience of psychosocial stress influences physical activity levels and weight status in adults. This study reports temporally ordered relationships between sedentary, light, and moderate-to-vigorous physical activity levels and real-time reports of subjective psychosocial stress levels. Adults (n=105) wore an accelerometer and participated in an ecological momentary assessment (EMA) of stress by answering prompts on a mobile phone several times per day over 4 days. Subjective stress was negatively related to sedentary activity in the minutes immediately preceding and immediately following an EMA prompt. Light activity was positively associated with a subsequent EMA report of higher stress, but there were no observed associations between stress and moderate-to-vigorous activity. Real-time stress reports and accelerometer readings for the same 4-day period showed no association. Nor were there associations between real-time stress reports and weight status.

Feasibility and Performance Test of a Real-Time Sensor-Informed Context-Sensitive Ecological Momentary Assessment to Capture Physical Activity.

BACKGROUND: Objective physical activity monitors (eg, accelerometers) have high rates of nonwear and do not provide contextual information about behavior. OBJECTIVE: This study tested performance and value of a mobile phone app that combined objective and real-time self-report methods to measure physical activity using sensor-informed context-sensitive ecological momentary assessment (CS-EMA). METHODS: The app was programmed to prompt CS-EMA surveys immediately after 3 types of events detected by the mobile phone's built-in motion sensor: (1) Activity (ie, mobile phone movement), (2) No-Activity (ie, mobile phone nonmovement), and (3) No-Data (ie, mobile phone or app powered off). In addition, the app triggered random (ie, signal-contingent) ecological momentary assessment (R-EMA) prompts (up to 7 per day). A sample of 39 ethnically diverse high school students in the United States (aged 14-18, 54% female) tested the app over 14 continuous days during nonschool time. Both CS-EMA and R-EMA prompts assessed activity type (eg, reading or doing homework, eating or drinking, sports or exercising) and contextual characteristics of the activity (eg, location, social company, purpose). Activity was also measured with a waist-worn Actigraph accelerometer. RESULTS: The average CS-EMA + R-EMA prompt compliance and survey completion rates were 80.5% and 98.5%, respectively. More moderate-to-vigorous intensity physical activity was recorded by the waist-worn accelerometer in the 30 minutes before CS-EMA activity prompts (M=5.84 minutes) than CS-EMA No-Activity (M=1.11 minutes) and CS-EMA No-Data (M=0.76 minute) prompts (P's<.001). Participants were almost 5 times as likely to report going somewhere (ie, active or motorized transit) in the 30 minutes before CS-EMA Activity than R-EMA prompts (odds ratio=4.91, 95% confidence interval=2.16-11.12). CONCLUSIONS: Mobile phone apps using motion sensor-informed CS-EMA are acceptable among high school students and may be used to augment objective physical activity data collected from traditional waist-worn accelerometers.

State-wide dissemination of a school-based nutrition education programme: a RE-AIM (Reach, Efficacy, Adoption, Implementation, Maintenance) analysis.

OBJECTIVE: The current study evaluated the overall public health impact of the 'Shaping Up My Choices' (SMC) programme, a 10-week school-based nutrition education curriculum developed for third-grade students, using the RE-AIM (Reach, Efficacy, Adoption, Implementation, Maintenance) framework. DESIGN: Randomized controlled trial to evaluate the programme and secondary analysis of archival data to describe dissemination. Data were collected from programme records, teacher surveys and student pre-, post- and 3-month follow-up surveys. SETTING: Public elementary schools in California. SUBJECTS: An evaluation sample (938 students and nineteen teachers) and a dissemination sample (195 245 students and 7359 teachers). RESULTS: In the evaluation sample, differences between the control and intervention groups were observed for nutrition knowledge, self-efficacy, outcome expectancies, and intakes of vegetables, fruit (girls only), soda, and low-nutrient high-energy foods from pre- to post-survey. Group differences in change in knowledge, outcome expectancies and vegetable intake were sustained through the 3-month follow-up (efficacy). One hundred per cent of intervention teachers in the evaluation sample implemented all of the lessons (implementation). The dissemination sample represented 42% of third-grade students (reach) and 39% of third-grade classrooms in public elementary schools in California during 2010-2011 (adoption). Thirty-seven per cent of third-grade teachers in the dissemination sample reordered SMC materials during the subsequent school year (2011-2012; maintenance). CONCLUSIONS: The SMC programme demonstrates the potential for moderate to high public health impact.

Locations of joint physical activity in parent-child pairs based on accelerometer and GPS monitoring.

BACKGROUND: Parental factors may play an important role in influencing children's physical activity levels. PURPOSE: This cross-sectional study sought to describe the locations of joint physical activity among parents and children. METHODS: Parent-child pairs (N = 291) wore an Actigraph GT2M accelerometer and GlobalSat BT-335 global positioning systems (GPS) device over the same 7-day period. Children were ages 8-14 years. Joint behavior was defined by a linear separation distance of less than 50 m between parent and child. Land use classifications were assigned to GPS datapoints. RESULTS: Joint physical activity was spread across residential locations (35 %), and commercial venues (24 %), and open spaces/parks (20 %). Obese children and parents performed less joint physical activity in open spaces/parks than under/normal weight children and parents (ps < 0.01). CONCLUSIONS: Understanding where joint parent-child physical activity naturally occurs may inform location-based interventions to promote these behaviors.

Associations of Maternal and Paternal Parenting Practices With Children's Fruit and Vegetable Intake and Physical Activity: Preliminary Findings From an Ecological Momentary Study.

BACKGROUND: Childhood obesity prevention interventions routinely focus on changing maternal parenting practices. Failure to assess how fathers' weight-related (ie, diet and physical activity) parenting practices contribute to children's energy balance behaviors limits the understanding of their paternal role within the family. Examining the independent and interacting effects of fathers' and mothers' weight-related parenting practices on children's diet and physical activity addresses this important research gap. OBJECTIVE: This study used ecological momentary assessment (EMA) to investigate the within-subject and between-subject independent and interactive effects of maternal and paternal encouragement to eat and preparation of fruits and vegetables (F/V) and encouragement of and taking their child to be physically active on their child's self-reported F/V intake and physical activity engagement. METHODS: Participants included mother-father-child triads (n=22 triads, n=205-213 prompts/occasions) in the Mothers and Their Children's Health Study and the University of Southern California Fathers Study. Simultaneously, mothers and fathers (agesmean 44.2 years, SD 5.6, and 45.2 years, SD 8.1, respectively), and their children (agemean 12.0 years, SD 0.7) completed up to 8 randomly prompted EMA surveys per day on separate smartphones for 7 days. At each prompt, mothers and fathers each reported whether they did the following in the past 2 hours: (1) encouraged their child to eat F/V, (2) prepared F/V for their child, (3) encouraged their child to be physically active, or (4) took their child to be physically active. Children self-reported whether they consumed F/V or were physically active in the past 2 hours. RESULTS: Results from Bayesian multilevel logistic models (all in log-odd units) indicated that at the within-subject level, greater maternal encouragement (ß=2.28, 95% CI 0.08 to 5.68) of eating F/V was associated with greater child report of eating F/V, but paternal encouragement (ß=1.50, 95% CI -0.83 to 4.52) showed no effects above and beyond maternal encouragement. Additionally, greater than usual paternal encouragement (ß=2.28, 95% CI 0.08 to 5.54) and maternal encouragement (ß=2.94, 95% CI 0.36 to 6.69) of physical activity had significant independent effects and were associated with greater child report of physical activity. No other within-subject or between-subject associations nor interactive effects were significant. CONCLUSIONS: Findings from this study suggest that fathers play a role in supporting their children's physical activity but not their intake of F/V. Future EMA studies should recruit larger samples to evaluate the independent and interacting roles of mothers' and fathers' weight-related parenting practices on child's obesogenic behaviors.

Identifying combinations of risk and protective factors predicting physical activity change in high school students.

Research sought to identify combinations of risk and protective factors predicting change in physical activity (PA) over one year in high school students. Adolescents (N = 344; M = 15.7 years) participated in a longitudinal study with assessment of demographics, substance use/smoking exposure, height and weight, psychological factors, and PA in 10th and 11th grade. PA participation in 11th grade was greatest for adolescents who engaged in PA and had high sports competence (78%), and least for adolescents who did not engage in or enjoy PA (13%) in 10th grade. Identifying adolescent subgroups at risk for decreasing PA can inform the development of tailored interventions.

Using ecological momentary assessment to examine antecedents and correlates of physical activity bouts in adults age 50+ years: a pilot study.

BACKGROUND: National recommendations supporting the promotion of multiple short (10+ minute) physical activity bouts each day to increase overall physical activity levels in middle-aged and older adults underscore the need to identify antecedents and correlates of such daily physical activity episodes. PURPOSE: This pilot study used Ecological Momentary Assessment to examine the time-lagged and concurrent effects of empirically supported social, cognitive, affective, and physiological factors on physical activity among adults age 50+ years. METHODS: Participants (N = 23) responded to diary prompts on a handheld computer four times per day across a 2-week period. Moderate-to-vigorous physical activity (MVPA), self-efficacy, positive and negative affect, control, demand, fatigue, energy, social interactions, and stressful events were assessed during each sequence. RESULTS: Multivariate results showed that greater self-efficacy and control predicted greater MVPA at each subsequent assessment throughout the day (p < 0.05). Also, having a positive social interaction was concurrently related to higher levels of MVPA (p = 0.052). CONCLUSION: Time-varying multidimensional individual processes predict within daily physical activity levels.

Anticipated affective consequences of physical activity adoption and maintenance.

OBJECTIVE: The expected emotional consequences of future actions are thought to play an important role in health behavior change. This research examined whether anticipated affective consequences of success and failure vary across stages of physical activity change and differentially predict physical activity adoption as compared to maintenance. DESIGN: Using a prospective design over a 3-month period, a community sample of 329 healthy, middle-aged adults were assessed at 2 time points. MAIN OUTCOME MEASURES: Anticipated positive and negative emotions, stage of behavior change (precontemplation [PC], contemplation [C], preparation [P], action [A], maintenance [M]), and level of physical activity. RESULTS: At baseline, anticipated positive emotions were greater in C versus PC, whereas anticipated negative emotions were greater in M versus A and in M versus P. Higher anticipated positive but not negative emotions predicted physical activity adoption and maintenance after 3 months. CONCLUSION: Although the expected affective consequences of future success and failure differentiated among individuals in the early and later stages of physical activity change, respectively; only the anticipated affective consequences of success predicted future behavior.

A tailored Internet-plus-email intervention for increasing physical activity among ethnically-diverse women.

OBJECTIVE: To evaluate the feasibility and efficacy of an individually tailored, Internet-plus-email physical activity intervention designed for adult women. METHOD: Healthy and ethnically-diverse adult females (N=156) (mean age=42.8 years, 65% Caucasian) from California were randomly assigned to an intervention (access to a tailored website and weekly emails) or wait-list control group. Participants completed web-based assessments of physical activity, stage of behavior change, and psychosocial variables at baseline, one month, two months, and three months. Data were collected during 2006-2007. Multilevel random coefficient modeling examined group differences in rates of change. RESULTS: As compared to the control condition, the intervention group increased walking (+69 versus +32 min per week) and total moderate-to-vigorous physical activity (+23 versus -25 min per week) after three months. The intervention did not impact stage of behavior change or any of the other psychosocial variables. CONCLUSION: A tailored, Internet-based intervention for adult women had a positive effect on walking and moderate-to-vigorous physical activity in an ethnically-diverse sample. However, given the lack of comparable research contact in the control group, these findings should be taken cautiously.

Social and physical environments of sports and exercise reported among adults in the American Time Use Survey.

OBJECTIVE: Demographic and temporal patterns in the social and physical environments of sports and exercise in the American Time Use Survey (years 2003-2006) are described. METHOD: The sample consisted of adult respondents (ages 21+) reporting at least one bout of sports or exercise (N=8844). During the interview, participants reported where (e.g., outdoors, home, work) and with whom (e.g., alone, family, coworkers) each bout occurred. Sample-weighted multinomial logistic regression analyses estimated the adjusted proportion of bouts occurring in each environment by gender, age, education, race/ethnicity, season, weekend/weekday, and time of day. RESULTS: Among members of the oldest age group (ages 60+), more exercise bouts occurred alone and outdoors compared to younger age groups. Among college graduates, more exercise bouts occurred at a gym/health club compared to groups with lower levels of education. Exercise bouts occurring alone were most likely to happen in the winter, on weekdays, and in the morning. Exercise bouts occurring outdoors were most likely to happen in the summer, on weekend days, and in the morning. CONCLUSION: Future research and intervention efforts exploring where, when and with whom exercise bouts occur may prove beneficial to addressing public health concerns about physical inactivity.

Physical Activity and Physical Self-Concept among Sedentary Adolescent Females; An Intervention Study.

PROBLEM: Physical activity has been promoted as a means of enhancing self-concept, yet the evidence for this connection is far from compelling. In particular, experimental research investigating this association during adolescence, a period during which many youth struggle to maintain a positive self-image, is noticeably lacking. This study investigates the impact on self-concept of a 9-month physical activity intervention among sedentary adolescent females. METHOD: Female adolescents who were sedentary at baseline were assigned either to an exercise intervention or a comparison group as part of the controlled trial. The intervention was school-based, and assignment to groups was based on school attended. Intervention participants engaged in supervised activity 4 times per week and received didactic instruction promoting activity outside of school 1 day per week. Self-concept, physical activity participation, and cardiovascular fitness were assessed before, mid-way through, and after the 9-month intervention. RESULTS: The intervention had a significant positive impact on participation in vigorous activity and cardiovascular fitness. The intervention did not significantly influence any of the self-concept dimensions overall. There was, however, a three-way interaction such that there was an increase in global physical self-concept among those intervention participants who increased cardiovascular fitness. CONCLUSIONS: These findings indicate that a physical activity intervention among sedentary adolescent females enhanced global physical self-concept for a subset of intervention participants who manifested positive changes in fitness.

Factors predicting behavioral response to a physical activity intervention among adolescent females.

OBJECTIVE: To determine whether individual factors influenced rates of physical activity change in response to a school-based intervention. METHODS: Sedentary adolescent females (N = 63) participated in a 9-month physical activity program. Weekly levels of leisure-time physical activity were reported using an interactive website. RESULTS: Change in vigorous activity was more positive among participants who had higher fitness and lower friend support at baseline. Change in moderate activity was more positive among participants who had lower fitness and external barriers, and higher internal barriers at baseline. CONCLUSIONS: Adolescent females responded differentially to a physical activity intervention depending on individual characteristics.

Differences in Mothers' and Children's Dietary Intake during Physical and Sedentary Activities: An Ecological Momentary Assessment Study.

BACKGROUND: Physical activity and diet are major modifiable health behaviors contributing to obesity risk. Although patterns of these behaviors tend to cluster within individuals and within family units, it is unknown to what extent healthy and unhealthy dietary intake might differentially accompany sedentary and physical activities in mothers compared with their children. OBJECTIVE: Our goal was to examine differences in co-occurrence of activities and dietary intake between mothers and children, as measured in real time using ecological momentary assessment. PARTICIPANTS/SETTING: This study examined cross-sectional data from 175 mothers and their children aged 8 to 12 years. MAIN OUTCOME MEASURES: Participants completed 8 days of ecological momentary assessment surveys, reporting on whether the following activities had occurred during the past 2 hours: sedentary screen activity, physical activity, and intake of healthy (ie, fruits and vegetables) and unhealthy (ie, fast food, chips/fries, pastries/sweets, and soda/energy drinks) foods. STATISTICAL ANALYSES PERFORMED: Multilevel logistic regression models estimated the adjusted odds of consuming healthy and unhealthy dietary intake for mothers and children during time periods reporting physical activity (vs no physical activity) or sedentary screen activity (vs no sedentary screen activity). Post hoc tests compared estimates for mothers vs children. RESULTS: Children were significantly more likely than their mothers to consume unhealthy foods during 2-hour windows that included physical activity (odds ratio [children] 1.85, 95% CI 1.47 to 2.31; odds ratio [mothers] 0.83, 95% CI 0.58 to 1.20; Pdiff <0.05), but not sedentary screen activity (Pdiff=0.067). In addition, children and their mothers did not differ in their likelihood of consuming healthy foods during 2-hour windows with sedentary screen activity (Pdiff =0.497) or physical activity (Pdiff =0.170). CONCLUSIONS: Results indicate that the consumption of unhealthy foods may be more likely to co-occur within a 2-hour window including physical activity in children as compared to their mothers. Future research should examine reasons for this difference, and potential areas for intervention.

Momentary assessment of contextual influences on affective response during physical activity.

OBJECTIVE: Higher positive and lower negative affective response during physical activity may reinforce motivation to engage in future activity. However, affective response during physical activity is typically examined under controlled laboratory conditions. This research used ecological momentary assessment (EMA) to examine social and physical contextual influences on momentary affective response during physical activity in naturalistic settings. METHOD: Participants included 116 adults (mean age = 40.3 years, 73% female) who completed 8 randomly prompted EMA surveys per day for 4 days across 3 semiannual waves. EMA surveys measured current activity level, social context, and physical context. Participants also rated their current positive and negative affect. Multilevel models assessed whether momentary physical activity level moderated differences in affective response across contexts controlling for day of the week, time of day, and activity intensity (measured by accelerometer). RESULTS: The Activity Level × Alone interaction was significant for predicting positive affect (ß = -0.302, SE = 0.133, p = .024). Greater positive affect during physical activity was reported when with other people (vs. alone). The Activity Level × Outdoors interaction was significant for predicting negative affect (ß = -0.206, SE = 0.097, p = .034). Lower negative affect during physical activity was reported outdoors (vs. indoors). CONCLUSIONS: Being with other people may enhance positive affective response during physical activity, and being outdoors may dampen negative affective response during physical activity.

Assessing the perceived environment among minimally active adolescent girls: validity and relations to physical activity outcomes.

PURPOSE: This study examined how adolescents' perceptions of exercise resources in the environment relate to physical activity outcomes. METHODS: Perceptions of the availability and use of environmental resources, vigorous physical activity (VIG), daily energy expenditure (KCAL), lifestyle activities (LA), and cardiovascular fitness (Vo2peak) were assessed cross-sectionally among 87 minimally active adolescent girls (ages 14-17). To validate adolescent reports, the perceived availability of environmental resources was also assessed from 47 parents. RESULTS: Adolescent-parent agreement over the availability of resources was modest for the home domain (r = .62, p < .001) and weak for the community domain (r = .14, p > .05). Adolescents' perceptions of resource availability in both the home and community domains were positively associated with VO2peak (p < .05) but unrelated to VIG, KCAL, and LA. Adolescents' use of home resources was positively correlated with both VIG and LA (p < .05). CONCLUSION: Minimally active adolescent girls were more attuned to and likely to use the resources for physical activity located in their home environment as opposed to the community environment.

Neighborhood park use by children: use of accelerometry and global positioning systems.

BACKGROUND: Although having a greater number of neighborhood parks may be associated with greater overall physical activity in children, information is lacking about the extent to which children actually use parks for physical activity. PURPOSE: This study combined accelerometer, GPS, GIS, and self-report methods to examine neighborhood park availability, perceived proximity, and use for physical activity in children. METHODS: Low- to middle-income children (aged 8-14 years) (n=135) from suburban communities in Southern California wore an Actigraph accelerometer and GlobalSat BT-335 GPS device across 7 days to measure physical activity and park use, respectively. ArcGIS identified parks within a 500-m residential buffer of children's homes. Parents reported perceptions of neighborhood park proximity through the Neighborhood Environment Walkability Survey (NEWS). Data were collected from March 2009 to December 2010, and analyzed in 2013. RESULTS: Fifty-four percent of families lived within 500 m of a park. Of these children, GPS data indicated that 16% used it more than 15 minutes and an additional 11% of children used it between 5 and 15 minutes during the 7-day study period. The odds of extended park use (>15 minutes) increased fourfold when the distance between home and the nearest neighborhood park decreased by 100 m. Additionally, the odds of any park use (>5 minutes) doubled when moving from the 25th to the 75th percentile for park greenness/vegetation density. CONCLUSIONS: Although children's use of neighborhood parks was generally low, it increased substantially when parks were closer to children's homes and had greater vegetation density.