The role of self-efficacy and information processing in weight loss during an mHealth behavioral intervention.

Self-efficacy (SE) and information processing (IP) may be important constructs to target when designing mHealth interventions for weight loss. The goal of this study was to examine the relationship between SE and IP with weight loss at six-months as part of the Dietary Interventions Examining Tracking with mobile study, a six-month randomized trial with content delivered remotely via twice-weekly podcasts. Participants were randomized to self-monitor their diet with either a mobile app (n = 42) or wearable Bite Counter device (n = 39). SE was assessed using the Weight Efficacy Life-Style Questionnaire and the IP variables assessed included user control, cognitive load, novelty, elaboration. Regression analysis examined the relationship between weight loss, SE change & IP at six months. Results indicate that elaboration was the strongest predictor of weight loss (ß =-0.423, P = 0.011) among all SE & IP variables and that for every point increase in elaboration, participants lost 0.34 kg body weight.

Effects of a food hub initiative in a disadvantaged community: A quasi-experimental evaluation.

A quasi-experiment evaluated a food hub's (FH) impact in a low-income/low-access (food desert) setting on fruit and vegetable (F&V) intake, diet quality, kilocalories, perceived food environment, BMI, and farmers' market shopping versus a matched community (n = 265 FH, n = 262 Comparison). Comparison shoppers had better baseline perceptions of their food environment, but FH shoppers improved significantly more than Comparison shoppers. Comparison shoppers significantly increased F&V intake versus FH shoppers. Effects were not significant for other diet outcomes, BMI, or farmers' market shopping. Factors besides spacial access to healthy food need consideration to address dietary intake and obesity in disadvantaged communities.

Correlates of physical activity among African American and white women.

OBJECTIVE: To compare potential correlates of physical activity between African American and white women. METHODS: A random-digit-dialed telephone survey was conducted in central South Carolina. Bivariate and multivariate analyses focused on women aged 18+ (N = 1176). RESULTS: African American women reported greater maintenance of sidewalks and public parks than did white women, who reported higher physical activity, exercise self-efficacy, access to indoor walking facilities, and knowledge of mapped-out walking routes. Exercise self-efficacy was the only significant correlate of physical activity among both African American and white women. CONCLUSIONS: Self-efficacy was a robust cross-sectional correlate of physical activity in women.

Household food security and use of community food sources and food assistance programs among food shoppers in neighborhoods of low income and low food access.

Food insecurity exceeds the 14% national level in severely disadvantaged households, and food shoppers seek food sources and assistance. In 513 predominantly African American households in South Carolina, USA, food security was a significant predictor of sources used, adjusted for socio-demographic characteristics (least-squares means = high food security, 2.10; marginal, 2.96; low, 2.91; very low, 3.40). The top sources were churches/social services, food bank/pantry, farmers' market, family/friend/neighbor, soup kitchen/shelter, and hunting/fishing/trapping. Adjusted odds were significantly greater among households of lower food security levels compared to high food security for food from church/social services, food bank/pantry, family/friend/neighbors, soup kitchen/shelter, and community/school/church garden.

Byte by Bite: Use of a mobile Bite Counter and weekly behavioral challenges to promote weight loss.

The goal of this study was to examine the usability and feasibility of the mobile Bite Counter (a watch-like device that detects when a user consumes food or beverage) and the impact of weekly behavioral challenges on diet and physical activity outcomes. Overweight (mean BMI 31.1±4.9 kg/m2) adults (n=12) were recruited to participate in a four-week study to test both the usability and feasibility of using the device as part of a behavioral weight loss intervention. Participants were instructed to self-monitor number of bites/day using the Bite Counter, attend weekly group sessions, and listen to weekly podcasts. Participants were given weekly challenges: use a daily bite limit goal (wk1), turn off Bite Counter when fruits/vegetables are consumed (wk2), self-monitor kilocalories vs. bites (wk3), and receive a 10 bites/day bonus for every 30 minutes of exercise (wk4). Participants lost a mean of -1.2±1.3 kg. Only the wk3 challenge produced significant differences in kcal change (wk3 1302±120 kcal/day vs. baseline 2042±302 kcal/d, P<0.05). Bite Counter use was significantly correlated with weight loss (r= -0.58, P<0.05). Future studies should examine the use of the Bite Counter and impact of behavioral challenges over a longer period of time in a controlled study.

The Dietary Intervention to Enhance Tracking with Mobile Devices (DIET Mobile) Study: A 6-Month Randomized Weight Loss Trial.

OBJECTIVE: To examine the use of two different mobile dietary self-monitoring methods for weight loss. METHODS: Adults with overweight (n = 81; mean BMI 34.7 ± 5.6 kg/m2 ) were randomized to self-monitor their diet with a mobile app (App, n = 42) or wearable Bite Counter device (Bite, n = 39). Both groups received the same behavioral weight loss information via twice-weekly podcasts. Weight, physical activity (International Physical Activity Questionnaire), and energy intake (two dietary recalls) were assessed at 0, 3, and 6 months. RESULTS: At 6 months, 75% of participants completed the trial. The App group lost significantly more weight (-6.8 ± 0.8 kg) than the Bite group (-3.0 ± 0.8 kg; group × time interaction: P < 0.001). Changes in energy intake (kcal/d) (-621 ± 157 App, -456 ± 167 Bite; P = 0.47) or number of days diet was tracked (90.7 ± 9.1 App, 68.4 ± 9.8 Bite; P = 0.09) did not differ between groups, but the Bite group had significant increases in physical activity metabolic equivalents (+2015.4 ± 684.6 min/wk; P = 0.02) compared to little change in the App group (-136.5 ± 630.6; P = 0.02). Total weight loss was significantly correlated with number of podcasts downloaded (r = -0.33, P < 0.01) and number of days diet was tracked (r = -0.33, P < 0.01). CONCLUSIONS: While frequency of diet tracking was similar between the App and Bite groups, there was greater weight loss observed in the App group.

Crowdsourcing for self-monitoring: Using the Traffic Light Diet and crowdsourcing to provide dietary feedback.

BACKGROUND: Smartphone photography and crowdsourcing feedback could reduce participant burden for dietary self-monitoring. OBJECTIVES: To assess if untrained individuals can accurately crowdsource diet quality ratings of food photos using the Traffic Light Diet (TLD) approach. METHODS: Participants were recruited via Amazon Mechanical Turk and read a one-page description on the TLD. The study examined the participant accuracy score (total number of correctly categorized foods as red, yellow, or green per person), the food accuracy score (accuracy by which each food was categorized), and if the accuracy of ratings increased when more users were included in the crowdsourcing. For each of a range of possible crowd sizes (n = 15, n = 30, etc.), 10,000 bootstrap samples were drawn and a 95% confidence interval (CI) for accuracy constructed using the 2.5th and 97.5th percentiles. RESULTS: Participants (n = 75; body mass index 28.0 ± 7.5; age 36 ± 11; 59% attempting weight loss) rated 10 foods as red, yellow, or green. Raters demonstrated high red/yellow/green accuracy (>75%) examining all foods. Mean accuracy score per participant was 77.6 ± 14.0%. Individual photos were rated accurately the majority of the time (range = 50%-100%). There was little variation in the 95% CI for each of the five different crowd sizes, indicating that large numbers of individuals may not be needed to accurately crowdsource foods. CONCLUSIONS: Nutrition-novice users can be trained easily to rate foods using the TLD. Since feedback from crowdsourcing relies on the agreement of the majority, this method holds promise as a low-burden approach to providing diet-quality feedback.

Depressive symptoms are associated with dietary intake but not physical activity among overweight and obese women from disadvantaged neighborhoods.

Evidence suggests that depressive symptoms are associated with poorer dietary intake and inadequate physical activity; however, this association has not been examined in lower-income overweight and obese African American women. The objective of this cross-sectional study was to examine the associations between depressive symptoms and diet and physical activity in 196 women (87% African American; age, 25-51 years). Higher depressive symptoms were hypothesized to predict poorer diet quality, greater emotional eating, lower physical activity levels, and greater sedentary time. Depressive symptoms were measured using the validated short form of the Center for Epidemiological Studies Depression Scale. Dietary intake and quality were assessed using three 24-hour dietary recalls. Emotional eating was evaluated using 4 items from the emotional eating subscale of the Eating Behavior Patterns Questionnaire. Physical activity and sedentary time were objectively measured using the ActiGraph accelerometer. Linear regression models tested the associations between depressive symptoms and each dietary and physical activity outcome variable. Symptoms of depression were positively associated with total daily caloric intake from saturated fat and total sugars, as well as emotional eating scores (P < .05). Although not statistically significant, depressive symptoms were positively associated with sweetened beverage consumption (P = .06) and added sugars (P = .07). Depressive symptoms were not associated with total fat, sodium, fruit and vegetables, fast food consumption, the Alternate Healthy Eating Index score, moderate-to-vigorous physical activity, or sedentary time. Future studies should explore the mechanisms linking the identified associations between depressive symptoms and dietary intake, such as the role of emotional eating.

Impact of a community-based prevention marketing intervention to promote physical activity among middle-aged women.

A physical activity intervention applied principles of community-based participatory research, the community-based prevention marketing framework, and social cognitive theory. A nonrandomized design included women ages 35 to 54 in the southeastern United States. Women (n = 430 preprogram, n = 217 postprogram) enrolled in a 24-week behavioral intervention and were exposed to a media campaign. They were compared to cross-sectional survey samples at pre- (n = 245) and postprogram (n = 820) from the media exposed county and a no-intervention county (n = 234 pre, n = 822 post). Women in the behavioral intervention had statistically significant positive changes on physical activity minutes, walking, park and trail use, knowledge of mapped routes and exercise partner, and negative change on exercise self-efficacy. Media exposed women had statistically significant pre- to postprogram differences on knowledge of mapped routes. No-intervention women had significant pre- to postprogram differences on physical activity minutes, walking, and knowledge of mapped routes.