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BackgroundIncreasing physical activity (PA) levels in adolescents aged 12 to 18 years is associated with prevention of unhealthy weight gain and improvement in cardiovascular fitness. The widespread availability of mobile health (mHealth) and wearable devices offers self-monitoring and motivational features for increasing PA levels and improving adherence to exercise programs. ObjectiveThe aim of this scoping review was to identify the efficacy or effectiveness of mHealth intervention strategies for facilitating PA among adolescents aged 12 to 18 years. MethodsWe conducted a systematic search for peer-reviewed studies published between 2008 and 2018 in the following electronic databases: PubMed, Google Scholar, PsychINFO, or SportDiscus. The search terms used included mHealth or “mobile health” or apps, “physical activity” or exercise, children or adolescents or teens or “young adults” or kids, and efficacy or effectiveness. Articles published outside of the date range (July 2008 to October 2018) and non-English articles were removed before abstract review. Three reviewers assessed all abstracts against the inclusion and exclusion criteria. Any uncertainties or differences in opinion were discussed as a group. The inclusion criteria were that the studies should (1) have an mHealth component, (2) target participants aged between 12 and 18 years, (3) have results on efficacy or effectiveness, and (4) assess PA-related outcomes. Reviews, abstracts only, protocols without results, and short message service text messaging–only interventions were excluded. We also extracted potentially relevant papers from reviews. At least 2 reviewers examined all full articles for fit with the criteria and extracted data for analysis. Data extracted from selected studies included study population, study type, components of PA intervention, and PA outcome results. ResultsOverall, 126 articles were initially identified. Reviewers pulled 18 additional articles from excluded review papers. Only 18 articles were passed onto full review, and 16 were kept for analysis. The included studies differed in the sizes of the study populations (11-607 participants), locations of the study sites (7 countries), study setting, and study design. Overall, 5 mHealth intervention categories were identified: website, website+wearable, app, wearable+app, and website+wearable+app. The most common measures reported were subjective weekly PA (4/13) and objective daily moderate-to-vigorous PA (5/13) of the 19 different PA outcomes assessed. Furthermore, 5 of 13 studies with a control or comparison group showed a significant improvement in PA outcomes between the intervention group and the control or comparison group. Of those 5 studies, 3 permitted isolation of mHealth intervention components in the analysis. ConclusionsPA outcomes for adolescents improved over time through mHealth intervention use; however, the lack of consistency in chosen PA outcome measures, paucity of significant outcomes via between-group analyses, and the various study designs that prevent separating the effects of intervention components calls into question their true effect.

BackgroundOnly one in five American meets the physical activity recommendations of the Department of Health and Human Services. The proliferation of wearable devices and smartphones for physical activity tracking has led to an increasing number of interventions designed to facilitate regular physical activity, in particular to address the obesity epidemic, but also for cardiovascular disease patients, cancer survivors, and older adults. However, the inconsistent findings pertaining to the accuracy of wearable devices for step counting needs to be addressed, as well as factors known to affect gait (and thus potentially impact accuracy) such as age, body mass index (BMI), or leading arm. ObjectiveWe aim to assess the accuracy of recent mobile devices for counting steps, across three different age groups. MethodsWe recruited 60 participants in three age groups: 18-39 years, 40-64 years, and 65-84 years, who completed two separate 1000 step walks on a treadmill at a self-selected speed between 2 and 3 miles per hour. We tested two smartphones attached on each side of the waist, and five wrist-based devices worn on both wrists (2 devices on one wrist and 3 devices on the other), as well as the Actigraph wGT3X-BT, and swapped sides between each walk. All devices were swapped dominant-to-nondominant side and vice-versa between the two 1000 step walks. The number of steps was recorded with a tally counter. Age, sex, height, weight, and dominant hand were self-reported by each participant. ResultsAmong the 60 participants, 36 were female (60%) and 54 were right-handed (90%). Median age was 53 years (min=19, max=83), median BMI was 24.1 (min=18.4, max=39.6). There was no significant difference in left- and right-hand step counts by device. Our analyses show that the Fitbit Surge significantly undercounted steps across all age groups. Samsung Gear S2 significantly undercounted steps only for participants among the 40-64 year age group. Finally, the Nexus 6P significantly undercounted steps for the group ranging from 65-84 years. ConclusionsOur analysis shows that apart from the Fitbit Surge, most of the recent mobile devices we tested do not overcount or undercount steps in the 18-39-year-old age group, however some devices undercount steps in older age groups. This finding suggests that accuracy in step counting may be an issue with some popular wearable devices, and that age may be a factor in undercounting. These results are particularly important for clinical interventions using such devices and other activity trackers, in particular to balance energy requirements with energy expenditure in the context of a weight loss intervention program.

Objective: The aim of this study was to identify predictors of weight regain and continued weight maintenance among individuals already successful at long‐term weight loss in a widely available weight‐management program. Methods: Participants were 2843 weight‐loss maintainers in WeightWatchers who had maintained weight loss ≥9.1 kg for ≥1 year (average 25.5 kg for 3.5 years; BMI = 26.7 kg/m2). Validated behavioral, psychosocial, and home environmental questionnaires were administered at study entry and 1 year later. Discriminant analysis identified variables that discriminated gainers (≥2.3‐kg gain) from maintainers (±2.3‐kg change). Results: Over the 1 year of follow‐up, 43% were gainers (mean [SD], 7.2 [5.4] kg), and 57% were maintainers (0.4 [1.2] kg). Compared with maintainers, gainers were younger and had higher initial weight, more recent weight losses, and larger initial weight losses. Standardized canonical coefficients indicated that the 1‐year changes that most discriminated gainers from maintainers were greater decreases in the ability to accept uncomfortable food cravings, urges, and desires to overeat (0.232); self‐monitoring (0.166); body image (0.363); and body satisfaction (0.194) and greater increases in disinhibition (0.309) and bodily pain (0.147). The canonical correlation was 0.505 (p < 0.001). Conclusions: Future interventions to prevent regain should consider targeting overeating in response to internal and external food cues and declines in self‐monitoring and body image. [ABSTRACT FROM AUTHOR]

Objective: Self-monitoring and behavioral feedback are widely used to help people monitor progress toward daily physical activity goals. Little information exists about the optimal dosing parameters for these techniques or if they are interchangeable in digital physical activity interventions. This study used a within-person experimental design to evaluate associations between the frequency of two different prompt types (one for each technique) and daily physical activity. Method: Insufficiently active young adults were assigned monthly physical activity goals and wore smartwatches with activity trackers for 3 months. They received zero to six randomly selected and timed watch-based prompts each day, with individual prompts either providing behavioral feedback or prompting the participant to self-monitor. Results: Physical activity increased significantly over the 3-month period (step counts d= 1.03; moderate-to-vigorous physical activity duration d =0.99). Mixed linear models revealed that daily step counts were positively associated with the frequency of daily self-monitoring prompts up to approximately three prompts/day (d =0.22) after which additional prompts provided minimal or reduced benefit. Daily step counts were not associated with the frequency of behavioral feedback prompts. Daily moderate-to-vigorous physical activity was not associated with the frequency of either prompt. Conclusions: Self-monitoring and behavioral feedback are not interchangeable behavior change techniques in digital physical activity interventions, and only self-monitoring prompts show signs of a dose-response association with physical activity volume. Activity trackers, such as smartwatches and mobile apps, should provide an option to replace behavioral feedback prompts with self-monitoring prompts to promote physical activity among insufficiently active young adults. [ABSTRACT FROM AUTHOR]

Background: The COVID-19 pandemic adversely impacted physical activity, but little is known about how contextual changes following the pandemic declaration impacted either the dynamics of people's physical activity or their responses to micro-interventions for promoting physical activity.Purpose: This paper explored the effect of the COVID-19 pandemic on the dynamics of physical activity responses to digital message interventions.Methods: Insufficiently-active young adults (18-29 years; N = 22) were recruited from November 2019 to January 2020 and wore a Fitbit smartwatch for 6 months. They received 0-6 messages/day via smartphone app notifications, timed and selected at random from three content libraries (Move More, Sit Less, and Inspirational Quotes). System identification techniques from control systems engineering were used to identify person-specific dynamical models of physical activity in response to messages before and after the pandemic declaration on March 13, 2020.Results: Daily step counts decreased significantly following the pandemic declaration on weekdays (Cohen's d = -1.40) but not on weekends (d = -0.26). The mean overall speed of the response describing physical activity (dominant pole magnitude) did not change significantly on either weekdays (d = -0.18) or weekends (d = -0.21). In contrast, there was limited rank-order consistency in specific features of intervention responses from before to after the pandemic declaration.Conclusions: Generalizing models of behavioral dynamics across dramatically different environmental contexts (and participants) may lead to flawed decision rules for just-in-time physical activity interventions. Periodic model-based adaptations to person-specific decision rules (i.e., continuous tuning interventions) for digital messages are recommended when contexts change. [ABSTRACT FROM AUTHOR]

Summary: Background: Low objective socioeconomic status (SES) and subjective social status (SSS), one's perceived social rank, are associated with obesity. This association may be due, in part, to social status‐related differences in energy expenditure. Experimental studies are needed to assess the extent to which SES and SSS relate to energy expenditure. Objective: Assess the effects of experimentally manipulated social status and SSS on moderate‐to‐vigorous physical activity (MVPA) and sedentary behaviour. Methods: One hundred thirty‐three Hispanic adolescents aged 15–21 were randomized to a high or low social status position, facilitated through a rigged game of Monopoly™. SSS was assessed with MacArthur Scales. Post‐manipulation 24‐h MVPA and sedentary behaviour were assessed via accelerometry. Analyses were conducted with general linear regression models. Results: Experimentally manipulated social status did not significantly affect the total time spent in MVPA or sedentary behaviour; however, identifying as low SSS was significantly associated with less MVPA (p = 0.0060; 18.76 min less). Conclusions: Tewnty‐four‐hour MVPA and sedentary behaviour are not affected by an acute experimental manipulation of social status. However, low SSS, independent of SES, was associated with clinically significant differences in MVPA. SSS may be a better predictor of MVPA than SES among Hispanic adolescents, potentially influencing obesity, and other health‐related outcomes. [ABSTRACT FROM AUTHOR]

Background: Behavioral obesity interventions using an acceptance‐based therapy (ABT) approach have demonstrated efficacy for adults, yet feasibility and acceptability of tailoring an ABT intervention for adolescents remains unknown. Objective: This study assessed the feasibility and acceptability of an ABT healthy lifestyle intervention among diverse adolescent cisgender girls with overweight/obesity (OW/OB). Methods: Adolescent cisgender girls aged 14–19 with a BMI of ≥85th percentile‐for‐sex‐and‐age were recruited for participation in a single‐arm feasibility study. The primary outcomes were recruitment and retention while the secondary outcome was change in BMI Z‐score over the 6‐month intervention. Exploratory outcomes included obesity‐related factors, health‐related behaviors, and psychological factors. Results: Recruitment goals were achieved; 13 adolescents (>60% racial/ethnic minorities) participated in the intervention, and 11 completed the intervention (85% retention). In completers (n = 11), a mean decrease in BMI Z‐score of −0.15 (SD = 0.34, Cohen's d = −0.44) was observed. Improvements were also noted for change in percentage of 95th percentile (d = −0.35), percent body fat (d = −0.35), quality of life (d = 0.71), psychological flexibility (d = −0.86), and depression (d = −0.86). Conclusions: These preliminary findings suggest an ABT healthy lifestyle intervention tailored for adolescent cisgender girls with OW/OB may be an acceptable treatment that could lead to improvements in BMI Z‐score, obesity‐related measures, and psychological outcomes. [ABSTRACT FROM AUTHOR]

Objective: This randomized trial experimentally manipulated social status to assess effects on acute eating behavior and 24-hour energy balance.Methods: Participants (n = 133 Hispanics; age 15-21 years; 60.2% females) were randomized to low social status ("LOW") or high social status ("HIGH") conditions in a rigged game of Monopoly (Hasbro, Inc.). Acute energy intake in a lunchtime meal was measured by food scales. Twenty-four-hour energy balance was assessed via summation of resting metabolic rate (metabolic cart), physical activity energy expenditure (accelerometer), thermic effect of food, and subtraction of twenty-four-hour energy intake (food diary).Results: In the total sample, no significant differences were observed by study condition at lunchtime. LOW females consumed a greater percent of lunchtime daily energy needs (37.5%) relative to HIGH females (34.3%); however, this difference was not statistically significant (P = 0.291). In males, however, LOW consumed significantly less (36.5%) of their daily energy needs relative to HIGH males (45.8%; P = 0.001). For 24-hour energy balance, sex differences were nearly significant (P = 0.057; LOW females: surplus +200 kcal; HIGH males: surplus +445 kcal). Food-insecure individuals consumed a nearly significant greater lunchtime percent daily energy than those with food security (40.7% vs. 36.3%; P = 0.0797).Conclusions: The data demonstrate differential acute and 24-hour eating behavior responses between Hispanic male and female adolescents in experimentally manipulated conditions of low social status. [ABSTRACT FROM AUTHOR]

Low social status (SS) is a determinant of poor health status and is associated with increased disease burden. Obesity affects 20.6% of American adolescents, most of whom are from low-SS families. Contributors to the development of obesity among adolescents include sedentary behavior and low levels of physical activity. Environmental determinants—infrastructure, policy, and social relationships—influence engagement in physical activity and are affected by SS. Significant declines in physical activity have been documented during adolescence, and adolescents of low SS engage in significantly less physical activity per week than those with high SS. This article briefly reviews the literature on the relationship between SS and physical activity in adolescents and introduces a proposed biological mechanism that may explain that relationship. Characterizing the effects that SS can have on physical activity may help tailor clinical interventions and public health campaigns seeking to improve adolescent physical activity and weight management, thus increasing their effectiveness. This may be particularly beneficial for underserved populations. [ABSTRACT FROM AUTHOR]

Objective: To assess the relationship between adverse childhood experiences (ACEs) and cardiometabolic risk among Hispanic adolescents.Study Design: This cross-sectional study was conducted at an academic research center in Gainesville, Florida. Participants were locally recruited, and data were collected from June 2016 to July 2018. Participants (n = 133, 60.2% female) were healthy adolescents aged 15-21 years who self-identified as Hispanic, were born in the US, and had a body mass index (BMI) between ≥18.5 and ≤40 kg/m2. Primary outcomes were BMI, body fat percentage, waist circumference, and resting blood pressure. Associations between ACEs and cardiometabolic measures were assessed by multivariable logistic regression models, which controlled for sex, age, parental education, and food insecurity. Results were sex-stratified to assess potential variations.Results: Reporting ≥4 ACEs (28.6%) was significantly associated with a greater BMI (P = .004), body fat percentage (P = .02), and diastolic blood pressure (P = .05) compared with reporting <4 ACEs. Female participants reporting ≥4 ACEs were significantly more likely to have a greater BMI (P = .04) and body fat percentage (P = .03) whereas male participants reporting ≥4 ACEs were significantly more likely to have a greater BMI (P = .04), systolic blood pressure (P = .03), and diastolic blood pressure (P = .03).Conclusions: Hispanic adolescent participants who experienced ≥4 ACEs were more likely to have elevated risk markers of obesity and cardiometabolic disease. Further research is needed to elucidate the physiological mechanisms driving these relationships. [ABSTRACT FROM AUTHOR]

Relative to other racial/ethnic groups in the United States, Hispanic American (HA) youth have higher rates of overweight and obesity. Previous work suggests that low perceived social status (SS) promotes excess caloric intake and, thereby, development of obesity. Psychological resilience may play a role in reducing adverse eating behaviors and risk for obesity. The objective of this study was to investigate whether resilience (as measured by the Connor Davidson Resilience Scale) interacts with experimentally manipulated SS to affect dietary intake among HA adolescents (n = 132). Using a rigged game of Monopoly (Hasbro, Inc.), participants were randomized to a high or low SS condition. Following the Monopoly game, participants consumed an ad libitum lunch and their dietary intake was assessed. There was a significant interaction between resilience and experimentally manipulated SS for total energy intake (p = 0.006), percent energy needs consumed (p = 0.005), and sugar intake (p = 0.004). For the high SS condition, for each increase in resilience score, total energy intake decreased by 7.165 ± 2.866 kcal (p = 0.014) and percent energy needs consumed decreased by 0.394 ± 0.153 (p = 0.011). In the low SS condition, sugar intake increased by 0.621 ± 0.240 g for each increase in resilience score (p = 0.011). After correction for multiple comparisons, the aforementioned interactions, but not simple slopes, were statistically significant. [ABSTRACT FROM AUTHOR]

Eating behaviors, including unhealthy snacking or excessive snacking leading to excess calorie consumption, may contribute to obesity among adolescents. Socioeconomic status (SES) also significantly influences eating behaviors, and low SES is associated with increased risk for obesity. However, little is known regarding the relationship between snacking behavior and SES among adolescents and how this may contribute to obesity-related outcomes. The primary objective of this scoping review was to review the literature to assess and characterize the relationship between SES and snacking in adolescents. The secondary objective was to assess weight-related outcomes and their relation to snacking habits. Included articles were published between January 2000 and May 2019; written in English, Portuguese, or Spanish; and focused on adolescents (13–17 years). In total, 14 bibliographic databases were searched, and seven studies met the inclusion criteria. Preliminary evidence from the seven included studies suggests a weak but potential link between SES and snacking. Additionally, these dietary patterns seemed to differ by sex and income type of country. Finally, only three of the included studies addressed weight-related outcomes, but the overall available evidence suggests that snacking does not significantly affect weight-related outcomes. Due to the small number of included studies, results should be interpreted with caution. [ABSTRACT FROM AUTHOR]

Background: Digital smartphone messaging can be used to promote physical activity to large populations with limited cost. It is not clear which psychological constructs should be targeted by digital messages to promote physical activity. This gap presents a challenge for developing optimal content for digital messaging interventions., Objective: The aim of this study is to compare affectively framed and social cognitively framed messages on subsequent changes in physical activity using dynamical modeling techniques., Methods: We conducted a secondary analysis of data collected from a digital messaging intervention in insufficiently active young adults (18-29 years) recruited between April 2019 and July 2020 who wore a Fitbit smartwatch for 6 months. Participants received 0 to 6 messages at random per day across the intervention period. Messages were drawn from 3 content libraries: affectively framed, social cognitively framed, or inspirational quotes. Person-specific dynamical models were identified, and model features of impulse response and cumulative step response were extracted for comparison. Two-way repeated-measures ANOVAs evaluated the main effects and interaction of message type and day type on model features. This early-phase work with novel dynamic features may have been underpowered to detect differences between message types so results were interpreted descriptively., Results: Messages (n=20,689) were paired with valid physical activity monitoring data from 45 participants for analysis. Received messages were distributed as 40% affective (8299/20,689 messages), 39% social-cognitive (8187/20,689 messages), and 20% inspirational quotes (4219/20,689 messages). There were no statistically significant main effects for message type when evaluating the steady state of step responses. Participants demonstrated heterogeneity in intervention response: some had their strongest responses to affectively framed messages, some had their strongest responses to social cognitively framed messages, and some had their strongest responses to the inspirational quote messages., Conclusions: No single type of digital message content universally promotes physical activity. Future work should evaluate the effects of multiple message types so that content can be continuously tuned based on person-specific responses to each message type., (©Alexandra M Lee, Sahar Hojjatinia, Jimikaye B Courtney, Deborah Brunke-Reese, Sarah Hojjatinia, Constantino M Lagoa, David E Conroy. Originally published in JMIR Formative Research (https://formative.jmir.org), 21.04.2023.)

Undergraduate students living with chronic diseases attending universities where major biomedical research takes place are critical stakeholders in these programs, yet they often remain sequestered from them. A directed research curriculum about Type 1 Diabetes (T1D) was developed to better engage undergraduate students with personal connections to the disease in a large medical university setting world renowned for its research in this area. The course had the following student learning outcomes: (1) gain knowledge of major T1D research programs; (2) exposure to careers in T1D research and clinical care; and (3) recognize bioethical issues in T1D research., Competing Interests: Conflict of InterestThe authors declare that they have no conflict of interest., (© International Association of Medical Science Educators 2019.)

Low social status (SS) is a determinant of poor health status and is associated with increased disease burden. Obesity affects 20.6% of American adolescents, most of whom are from low-SS families. Contributors to the development of obesity among adolescents include sedentary behavior and low levels of physical activity. Environmental determinants-infrastructure, policy, and social relationships-influence engagement in physical activity and are affected by SS. Significant declines in physical activity have been documented during adolescence, and adolescents of low SS engage in significantly less physical activity per week than those with high SS. This article briefly reviews the literature on the relationship between SS and physical activity in adolescents and introduces a proposed biological mechanism that may explain that relationship. Characterizing the effects that SS can have on physical activity may help tailor clinical interventions and public health campaigns seeking to improve adolescent physical activity and weight management, thus increasing their effectiveness. This may be particularly beneficial for underserved populations., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.