Accuracy of self-reported physical activity levels in obese adolescents

Validity and reliability of self-reported methods for assessment of 24-h movement behaviours: a systematic review

BACKGROUND

Time spent in sleep, sedentary behaviour (SB), and physical activity are exhaustive and mutually exclusive parts of a 24-h day that need to be considered in a combination. The aim of this study was to identify validated self-reported tools for assessment of movement behaviours across the whole 24-h day, and to review their attributes and measurement properties.

METHODS

The databases PubMed, Scopus, and SPORTDiscus were searched until September 2023. Inclusion criteria were: (i) published in English language, (ii) per-reviewed paper, (iii) assessment of self-reported time spent in sleep, SB, and physical activity, (iv) evaluation of measurement properties of all estimates across the full 24-h day, and (v) inclusion of adolescents, adults, or older adults. The methodological quality of included studies was assessed using the Consensus-based Standards for the selection of health Measurement Instruments checklist.

RESULTS

Our search returned 2064 records. After studies selection, we included 16 articles that reported construct validity and/or test-retest reliability of 12 unique self-reported tools - eight questionnaires, three time-use recalls, and one time-use diary. Most tools enable assessment of time spent in sleep, and domain-specific SB and physical activity, and account that sum of behaviours should be 24 h. Validity (and reliability) correlation coefficients for sleep ranged between 0.22 and 0.69 (0.41 and 0.92), for SB between 0.06 and 0.57 (0.33 and 0.91), for light-intensity physical activity between 0.18 and 0.46 (0.55 and 0.94), and for moderate- to vigorous-intensity physical activity between 0.38 and 0.56 (0.59 and 0.94). The quality of included studies being mostly fair-to-good.

CONCLUSIONS

This review found that only a limited number of validated self-reported tools for assessment of 24-h movement behaviours are currently available. Validity and reliability of most tools are generally adequate to be used in epidemiological studies and population surveillance, while little is known about adequacy for individual level assessments and responsiveness to behavioural change. To further support research, policy, and practice, there is a need to develop new tools that resonate with the emerging 24-h movement paradigm and to evaluate measurement properties by using compositional data analysis.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42022330868.

Weekend physical activity profiles and their relationship with quality of life: The SOPHYA cohort of Swiss children and adolescents

INTRODUCTION

Quality of life (QoL) is an important health indicator among children and adolescents. Evidence on the effect of physical activity (PA)-related behaviors on QoL among youth remains inconsistent. Conventional accelerometer-derived PA metrics and guidelines with a focus on whole weeks may not adequately characterize QoL relevant PA behavior.

OBJECTIVE

This study aims to a) identify clusters of accelerometer-derived PA profiles during weekend days among children and adolescents living in Switzerland, b) assess their cross-sectional and predictive association with overall QoL and its dimensions, and c) investigate whether the associations of QoL with the newly identified clusters persist upon adjustment for the commonly used PA metrics moderate-to-vigorous physical activity (MVPA) and time spent in sedentary behavior (SB).

METHODS

The population-based Swiss children's Objectively measured PHYsical Activity (SOPHYA) cohort among children and adolescents aged 6 to 16 years was initiated at baseline in 2013. PA and QoL information was obtained twice over a five-year follow-up period. The primary endpoint is the overall QoL score and its six dimension scores obtained by KINDL® questionnaire. The primary predictor is the cluster membership of accelerometer-derived weekend PA profile. Clusters were obtained by applying the k-medoid algorithm to the distance matrix of profiles obtained by pairwise alignments of PA time series using the Dynamic Time Warping (DTW) algorithm. Secondary predictors are accelerometer-derived conventional PA metrics MVPA and SB from two combined weekend days. Linear regression models were applied to assess a) the cross-sectional association between PA cluster membership and QoL at baseline and b) the predictive association between PA cluster membership at baseline and QoL at follow-up, adjusting for baseline QoL.

RESULTS

The study sample for deriving PA profile clusters consisted of 51.4% girls and had an average age of 10.9 [SD 2.5] years). The elbow and silhouette methods indicated that weekend PA profiles are best classified in two or four clusters. The most differentiating characteristic for the two-clusters classification ("lower activity" and "high activity"), and the four-clusters classification ("inactive", "low activity", "medium activity", and "high activity"), respectively was the participant's mean counts per 15-seconds epoch. Participants assigned to high activity clusters were younger and more often male. Neither the clustered PA profiles nor MVPA or SB were cross-sectionally or predictively associated with overall QoL. The only association of a conventional PA metrics with QoL while adjusting for cluster membership was observed between MVPA during the weekend days and social well-being with a mean score difference of 2.4 (95%CI: 0.3 to 4.5; p = 0.025).

CONCLUSION

The absence of strong associations of PA metrics for the weekend with QoL, except for the positive association between MVPA during the weekend days and social well-being, is in line with results from two randomized studies not showing efficacy of PA interventions on youth QoL. But because PA decreases with age, its promotion and relevance to QoL remain important research topics. Larger longitudinal study samples with more than two follow-up time points of children and adolescents are needed to derive new novel accelerometer-derived PA profiles and to associate them with QoL dimensions.

Total energy expenditure measured by doubly labeled water method in children and adolescents: a systematic review

Total energy expenditure (TEE) is essential for understanding the growth, development, and physical activity of children and adolescents. This study aimed to summarize the existing evidence on TEE measured using the doubly labeled water (DLW) technique in children and adolescents aged 1-18 years. Furthermore, this review compared TEE between obese and normal-weight participants. This systematic review used the PubMed, ScienceDirect, Web of Science, and EBSCO databases. These studies were limited to those published in English between January 2000 and December 2021. Articles presenting objectively measured data on the TEE of children and adolescents aged 1-18 years measured using the DLW method were included. Physical activity level (PAL; TEE/basal metabolic rate [BMR]) and BMR data were also obtained. The search strategy identified 2,351 articles, of which 63 (n=4,283 children and adolescents; 45.4% male) met the selection criteria. The participants in the 10 studies were overweight or obese (n=413). In our study, TEE increased in male and female participants aged 1-18 years. PAL increased with age in males (y=0.0272x+1.3887, r2=0.511) and females (y=0.0199x+1.401, r2=0.335), and the slope of PAL with age did not differ between males and females. The TEE of obese and overweight participants was higher than that of normal-weight participants, but the slope of TEE did not differ between normal-weight (y=132.99x+702.24, r2=0.877) and obese individuals (y=136.18x+1,037.9, r2=0.842). In conclusion, this review provides convincing evidence that daily TEE progressively increases with growth in males and females aged 1-18 years.

Total Energy Expenditure in Healthy Ambulatory Older Adults Aged ≥80 Years: A Doubly Labelled Water Study

INTRODUCTION

The life expectancy of older adults continues to increase; however, knowledge regarding their total energy requirements is lacking. This study aimed to compare the total energy expenditure (TEE) of older adults ≥80 years measured using doubly labelled water (DLW), with estimated TEE. The hypothesis was that the Mifflin, Ikeda, and Livingston equations will more closely estimate energy requirements than the commonly used Schofield equation.

METHODS

Resting metabolic rate (RMR) and TEE were measured using the reference methods of indirect calorimetry and DLW, respectively. Bland-Altman plots compared measured RMR and TEE with predicted RMR using equations (Mifflin, Ikeda, Livingston, Schofield) and predicted TEE (predicted RMR × physical activity level).

RESULTS

Twenty-one older adults (age range 80.7-90.1 years, BMI 26.1 ± 5.5 kg/m2) were included. The Schofield equation demonstrated the greatest bias from measured RMR, overestimating approximately up to double the mean difference (865 ± 662 kJ/day) compared with the three other equations. The Schofield equation exhibited the greatest bias (overestimation of 641 ± 1,066 kJ/day) compared with measured TEE. The other three equations underestimated TEE, with the least bias from Ikeda (37 ± 1,103 kJ/day), followed by Livingston (251 ± 1,108 kJ/day), and Mifflin (354 ± 1,140 kJ/day). Data are mean ± SD.

CONCLUSIONS

In older adults ≥80 years, the Ikeda, Mifflin, and Livingston equations provide closer estimates of TEE than the widely used Schofield equation. The development of nutrition guidelines therefore should consider the utilization of equations which more accurately reflect age-specific requirements.

Objectively measured physical activity among treatment seeking children and adolescents with severe obesity and normal weight peers

Background

Treatment seeking children and adolescents with severe obesity often experience barriers to physical activity. Studies objectively measuring physical activity in this group and investigating explanatory factors for physical activity levels could inform clinical practice.

Objectives

This study aimed to compare objectively measured physical activity levels among treatment seeking children and adolescents with severe obesity and normal weight peers, and to investigate explanatory factors for time spent in moderate physical activity and vigorous physical activity among children and adolescents with severe obesity.

Methods

Children with severe obesity (n = 85) were matched 1:1 by age, gender, and the season for accelerometer measurements with normal weight peers (n = 85). Children wore accelerometers for seven consecutive days, yielding measures of physical activity, sleep duration and timing. Parents reported on screen time, parental body mass index and participation in organized sports.

Results

Children and adolescents with severe obesity spent significantly less time in moderate physical activity (12 min, p < 0.001) and vigorous physical activity (21 min, p < 0.001) per day compared to normal weight peers. No difference for time spent in sedentary activity was found between groups. For participants with severe obesity, age ≤12 years (p = 0.009) and participation in organized sports (p = 0.023) were related to more moderate physical activity, while age ≤12 years (p = 0.038) and early sleep timing (p = 0.019) were related to more vigorous physical activity.

Conclusion

Children and adolescents with severe obesity were less physically active than their normal weight peers. Factors related to more moderate and vigorous physical activity in children with severe obesity were lower age, participation in organized sports and earlier sleep timing.

The Compatibility of Children with Obesity to Self-Report Aspects of Physical Activity Domains

Questions about the different aspects of physical activity (PA) are commonly asked in the clinical setting, yet their compatibility for use with children, particularly children with obesity (OB) is uncertain. Our aim was to investigate different PA-related questions when compared to an objective maximal cardiopulmonary exercise test (CPET) or validated questionnaires. For this study, 33 normal-weight (NW) (5 to less than 85% BMI percentile) and 35 OB (≥95% BMI percentile) children responded to three self-report PA questions evaluating PA domains (exercise capacity, limitations, and the maintenance of an active lifestyle); they also completed a maximal CPET and two validated questionnaires: the New York Heart Association (NYHA) questionnaire and the international physical activity questionnaire (IPAQ). The results regarding the NW children were highly compatible with their self-reports about exercise capacity (85%), whereas the compatibility was low (40%) in the OB group (p < 0.001). Both OB and NW groups had moderate compatibility between the self-report and objective findings regarding their exercise limitations and lifestyle with no significant differences between the groups. These findings suggest that it is inadvisable to rely on a single-item question by which to assess PA in OB children, and no definite conclusions regarding PA status should be drawn. NW children are more compatible with self-reporting their overall exercise capacity, with more limited compatibilities observed when self-reporting their limitations or lifestyle.

Poor Health Related Quality of Life and Unhealthy Lifestyle Habits in Weight-Loss Treatment-Seeking Youth

Obesity is associated with unhealthy lifestyle behaviors and poor Health Related Quality of Life (HRQOL). The cumulative effect of lifestyle behaviors on HRQOL has been demonstrated in chronically ill adolescents, but not in adolescents with obesity. The present study aimed to assess the association between HRQOL and adherence to the Mediterranean Diet (MD) and/or low levels of physical activity (PA) in a large sample of outpatient adolescents with overweight or obesity seeking weight loss treatment. Four-hundred-twenty participants were enrolled from 10 Italian outpatient clinics. The demographics and anthropometric features, KIDMED scores, and exercise levels of the participants were collected, together with parental features. The HRQOL was assessed by the Pediatric Quality of Life Inventory (PedsQL™), Adolescents Version 4.0. PedsQL total score and functioning subscales were lower in adolescents who reported one or two unhealthy habits. Compared with the high/intermediate groups, the risk of low HRQOL was twice as high for each unit increase in BMI SDS, while the percentage was reduced by 12.2% for every unit increase in the KIDMED score and by 32.3% for each hour increase of exercise. The clustering of these two unhealthy behaviors conferred a 120% higher risk of low HRQOL. Similarly, adolescents displaying better diet quality and/or a physically more active lifestyle have better physical and psychological functioning. Further studies are needed to disclose whether these characteristics may be predictive of better adherence to weight loss treatment.

Mis-reporting of energy intake among older Australian adults: Prevalence, characteristics, and associations with quality of life

OBJECTIVES

Mis-reporting is common in dietary assessment, leading to misinterpretation of disease risk and could be important in older adults with increased chronic disease risk. This study investigated the prevalence and characteristics of mis-reporting among older adults and its association with health outcomes including quality of life (QoL).

METHODS

The study was conducted in 335 community-dwelling older adults at increased risk for cardiovascular disease, participating in the SCReening Evaluation of the Evolution of New Heart Failure Study dietary substudy. Diet was assessed using 4-day weighed food diaries, QoL measured through Short Form 36, and physical activity assessed using the European Prospective Investigation into Cancer and Nutrition physical activity questionnaire. Dietary mis-reporting was defined based on Goldberg cutoffs, using individual physical activity levels. Odds ratios were determined to establish associations between mis-reporting and health outcomes.

RESULTS

The prevalence of mis-reporting among older adults was 49.3%, with 44.5% of women mis-reporting their energy intake. The study found under-reporting of energy to be associated with body mass index, specifically being overweight (odds ratio: 3.08; 95% confidence interval [CI], 1.54-6.15) and obese (odds ratio: 6.60; 95% CI, 3.05-4.26), as well as physical inactivity (odds ratio: 0.24; 95% CI, 0.14-0.43). Only physical inactivity predicted over-reporting of dietary intake (odds ratio: 7.52; 95% CI, 1.57-36.0).

CONCLUSIONS

Dietary under-reporting was associated with being overweight, obese, and physically inactive in addition to the absence of comorbidities, reinforcing the need for further research in older adults to factor in dietary mis-reporting for meaningful diet-disease relationship analyses.

A Family-Based Lifestyle Intervention Focusing on Fathers and Their Children Using Co-Creation: Study Protocol of the Run Daddy Run Intervention

Fathers play a unique and important role in shaping their children’s physical activity (PA), independent from the mother. Lifestyle interventions focusing simultaneously on PA of fathers and their children (“co-PA”) are therefore a novel and promising way to improve PA of both. A theory-based lifestyle intervention was co-created with fathers (i.e., the Run Daddy Run intervention), using the behavior change wheel as a theoretical framework. The aim of the present study is to describe the protocol of the Run Daddy Run intervention study, focusing on improving (co-)PA of fathers and children, and the prospected outcomes. The developed intervention consists of six (inter)active father-child sessions and an eHealth component, delivered over a 14-week intervention period. Baseline measurements will be conducted between November 2019–January 2020, post-test measurements in June 2020, and follow-up measurements in November 2020, with (co-)PA as the primary outcome variable. Outcomes will be measured using accelerometry and an online questionnaire. To evaluate the intervention, multilevel analyses will be conducted. This study will increase our understanding on whether a theory-based, co-created lifestyle intervention focusing exclusively on fathers and their children can improve their (co-)PA behavior and has important implications for future research and health policy, where targeting fathers might be a novel and effective approach to improve (co-)PA and associated health behaviors of both fathers and their children.

Physical activity and sedentary behaviour in women with and without polycystic ovary syndrome: An Australian population-based cross-sectional study

OBJECTIVE

Lifestyle is the first-line treatment for women with polycystic ovary syndrome (PCOS). This study examines the physical activity (PA) levels and sedentary behaviours of women with and without PCOS, and their alignment with the PCOS PA guideline.

METHODS

This cross-sectional study on women (aged 22-27 years) in the Australian Longitudinal Study on Women's Health was conducted in 2019 using data collected in 2017. Self-reported PA levels and total daily sitting time (ST) of women with (n = 7051) and without (n = 796) self-reported PCOS were presented, stratified by body mass index (BMI) and a combined overweight/obese group.

RESULTS

71.0% and 56.7% of the entire study cohort achieved PA levels recommended for weight maintenance and weight loss, respectively. Overall, PA levels were lower and ST was higher in women with than without PCOS. In each BMI category, similar proportions of women with and without PCOS met the PA guidelines but became lower as BMI category increased. Fewer overweight/obese group women with than without PCOS aligned with recommendations for weight maintenance (58.7% vs 65.7%, P = .003) or weight loss (45.1% vs 50.3%, P = .032). ST ≥8 h/d was observed in two-thirds of women with and without self-reported PCOS similarly before and after stratifying by BMI.

CONCLUSION

High sedentary behaviour was extremely prevalent. Although the majority of women met PA recommendations for weight maintenance, only one in two overweight/obese women met PA recommendation for weight loss. Overweight/obese women with PCOS were more likely to participate in insufficient PA and require increased support to achieve sustainable healthy lifestyle.

A systematic review of the validity of dietary assessment methods in children when compared with the method of doubly labelled water

Assessing energy intake (EI) in children and adolescents is essential for monitoring population nutrition trends and interpreting clinical outcomes. The aim of this review was to examine the validity of dietary assessment methods for estimating EI in children and adolescents when compared with total energy expenditure (TEE) measured using doubly labelled water (DLW). Six online databases were searched to identify articles published in English. Studies were included if they were conducted in participants aged ≤18 years, if they estimated EI via a dietary assessment method, and if they compared this estimate to TEE measured using the DLW method. The search strategy identified 345 articles, of which 13 articles (12 studies) (n = 306 children) met the selection criteria. Five studies were carried out in children aged 5-11 years with dietary intake of children reported by parents/caregivers. The most common dietary assessment methods used were food frequency questionnaires (n = 5) and weighed food records (n = 4). All methods were found to have some level of misreporting. Child characteristics including weight status, age, and sex were not found to consistently influence the accuracy of reported EI. Five studies employing technology-assisted approaches for assessing dietary intake in children were identified and reported mixed findings. Validity studies using DLW remain sparse in the literature. Studies including participants less than 5 years or older than 11 years, and from diverse ethnicities and socioeconomic backgrounds are warranted to explore other demographic differences that may affect the accuracy of dietary assessment methods. While reported in few studies, technology-assisted methods were found to perform equally well in estimating intakes when compared to DLW and other traditional forms of dietary assessment.

The Effects of Parental Stress on Physical Activity Among Overweight and Obese Hispanic Adolescents: Moderating Role of Family Communication and Gender

BACKGROUND

Previous literature has shown a negative relationship between parental stress and youth moderate to vigorous physical activity (MVPA). This study examined (1) the relationship between parental stress and adolescent MVPA, (2) the moderating role of family communication on this relationship, and (3) gender differences in these effects among overweight and obese Hispanic adolescents.

METHODS

Hispanic adolescents (N = 280, 52% female, 13.0 [0.8] y old, 44% obese, 12% severely obese) and their parents (88% female, 44.9 [6.5] y old) completed baseline measures for an efficacy trial. Adolescents self-reported MVPA in minutes per week for work, transportation, and recreation using a validated measure. Multiple regression analyses with interaction terms and multigroup methods were conducted.

RESULTS

There was a negative effect of parental stress on adolescent MVPA (β = -0.15, t = -2.018, P ≤ .05). This effect was moderated by family communication (β = 0.20, t = 2.471, P = .01), such that the association between parental stress and youth MVPA was stronger for adolescents with low levels of family communication. Furthermore, a multiple group model showed that the interaction was significant for boys (β = 0.27, t = 2.185, P = .03), but not for girls.

CONCLUSIONS

Findings provide support that addressing parental stress and family communication may help facilitate MVPA among Hispanic boys, the most at-risk group for pediatric obesity.

Feasibility and Acceptability of a Self-Report Activity Diary in Families of Children With and Without Special Needs

This study was conducted to examine the feasibility and acceptability of a self-report activity diary completed by parents and older children to assess the child's daily activity in children with and without special needs. The study included 36 child/parent dyads stratified by child age and diagnosis. Parents (n = 36) and children ≥13 years (n = 12) were asked to report on the child's daily activity using an activity diary. Feasibility was determined based on successfully returned diaries and acceptability via post-study interview. Activity diaries were submitted by 94% of the parents and 100% of the children, with 83% and 80%, respectively, successfully completed. Comments provided post-study regarding the diaries were primarily on the format and were generally negative. The activity diary was feasible to use, but not well accepted within our sample of children with and without special needs or their parents. Further research is needed to create valid physical activity assessment measures that are population specific for individuals with special needs.

"With Every Step, We Grow Stronger": The Cardiometabolic Benefits of an Indigenous-Led and Community-Based Healthy Lifestyle Intervention

Community-based and Indigenous-led health and wellness approaches have been widely advocated for Indigenous peoples. However, remarkably few Indigenous designed and led interventions exist within the field. The purpose of this study was to evaluate an Indigenous-led and community-based health and wellness intervention in a remote and rural Indigenous community. This protocol was designed by and for Indigenous peoples based on the aspirations of the community (established through sharing circles). A total of 15 participants completed a 13-week walking and healthy lifestyle counselling program (incorporating motivational interviewing) to enhance cardiometabolic health. Measures of moderate-to-vigorous physical activity (MVPA; 7-day accelerometry and self-report), predicted maximal aerobic power (VO₂max; 6-min walk test), resting heart rate and blood pressure, and other health-related physical fitness measures (musculoskeletal fitness and body composition) were taken before and after the intervention. The intervention led to significant (p < 0.05) improvements in VO₂max (7.1 ± 6.3 % change), with the greatest improvements observed among individuals with lower baseline VO₂max (p < 0.05, r = -0.76). Resting heart rate, resting systolic blood pressure, and resting diastolic blood pressure decreased significantly (p < 0.05) after the intervention. Self-reported and accelerometry-measured frequency of MVPA increased significantly (p < 0.05), and the total MVPA minutes (~275 min/week) were above international recommendations. Change in VO₂max was significantly correlated with change in self-reported (r = 0.42) and accelerometry-measured (r = 0.24) MVPA minutes. No significant changes were observed in weight, body mass index, waist circumference, body fat (via bioelectrical impedance), grip strength, and flexibility. These findings demonstrate that a culturally relevant and safe, community-based, Indigenous-led, health and wellness intervention can lead to significant and clinically relevant improvements in cardiometabolic health and physical activity behaviour, with the greatest changes being observed in the least active/fit individuals.

Fear of falling in obese women under 50 years of age: a cross-sectional study with exploration of the relationship with physical activity

Background

An understanding of capacity for physical activity in obese populations should help guide interventions to promote physical activity. Fear of falling is a phenomenon reported in the elderly, which is associated with reduced mobility and lower physical activity levels. However, although falls are reportedly common in obese adults, fear of falling and its relationship with activity has not been investigated in younger obese populations.

Methods

In a cross-sectional study, fear of falling was measured in 63 women aged 18 to 49 years, with mean BMI 42.1 kg/m² (SD 10.3) using the Modified Falls Efficacy (MFES), the Consequences of Falling (COF) and the Modified Survey of Activities and Fear of Falling in the Elderly (MSAFFE) scales. The choice of scales was informed by prior qualitative interviews with obese younger women. Physical activity levels were measured at the same time using the International Physical Activity Questionnaire. The mean score for fear of falling scales, with 95% confidence intervals, were estimated. Chi-square tests and t-tests were used to explore differences in age, body mass index and fear of falling scores between fallers and non-fallers. For each fear of falling scale, binomial logistic regression was used to explore its relationship with physical activity.

Results

Mean scores suggested high levels of fear of falling: MFES [mean 7.7 (SD 2.7); median 8.5]; COF [mean 31.3 (SD 9.4)]; MSAFFE [mean 25.9 (SD 8.7); median 23]. Scores were significantly worse in fallers (n = 42) compared to non-fallers (n = 21). MFES and MSAFFE were independently associated with lower levels of physical activity [odds ratio = 0.65, 95% Cl 0.44 to 0.96 and odds ratio = 1.14, 95% CI 1.01 to 1.28 respectively], when adjusted for age, BMI and depression.

Conclusions

This study confirms that fear of falling is present in obese women under 50 years of age. It suggests that it is associated with low levels of physical activity. These novel findings warrant further research to understand capacity for physical and incidental activity in obese adults in both genders and suggest innovative interventions to promote lifestyle changes and/or consideration of falls prevention in this population.

Risk factors for diabetes are higher among non-heterosexual US high-school students

Low physical activity (PA), high sedentary behavior (SB), and overweight and obesity have been shown to associate with increased Type 2 diabetes risk among adolescents. We investigated PA, SB, and overweight and obesity among Youth Risk Behavior Survey (YRBS) respondents to determine if non-heterosexual youth may be at increased diabetes risk compared to heterosexual youth. Weighted city and state YRBS data were pooled across 44 jurisdictions biennially from 2009 to 2015, resulting in a sample size of 350 673 students. Overall, 88.4% identified as heterosexual, 2.1% as gay or lesbian, 5.7% as bisexual, and 3.7% as unsure. With the exception of lesbian female students, after adjusting for age, race/ethnicity, body mass index, and survey year, all non-heterosexual youth reported significantly fewer days per week of PA compared to their sex-matched heterosexual counterparts. Similarly, compared to heterosexual female youth, bisexual and not sure female youth reported significantly more hours per day of SB. These PA and SB findings remained significant after adjustment for depressive symptoms and in-school bullying among bisexual female youth only. In fully adjusted models, lesbian students were 1.85 times more likely to be overweight and lesbian, bisexual, and not sure female youth were 1.55 to 2.07 times more likely to be obese than heterosexual female students. No significant differences in SB, overweight, or obesity were found among gay, bisexual, or unsure male youth compared to heterosexual male youth. Non-heterosexual youth may be at increased risk for developing type 2 diabetes mellitus compared to heterosexual youth. Future studies should characterize diabetes prevalence among non-heterosexual youth.

Assessment of Key Health and Wellness Indicators Among North Carolina Emergency Medical Service Providers

OBJECTIVE

The objective of this study was to characterize key health indicators in Emergency Medical Services (EMS) personnel and identify areas for intervention in order to ensure a strong and capable emergency health workforce.

METHODS

Participants were EMS personnel delivering patients to 4 regional tertiary care emergency departments within North Carolina (NC). After transferring patient care and agreeing to participate, height, weight, and blood pressure (BP) measurements were recorded and each participant completed a questionnaire regarding demographics, activity levels, alcohol consumption, smoking, and medical history. Data were analyzed descriptively.

RESULTS

A sample of 452 EMS personnel from across NC was enrolled. The cohort was predominantly male (74.1%) and employed full-time (85.5%). The prevalence of overweight and obesity (80.3%) among EMS personnel was higher than the NC population (65.6%) and the general United States (US) population (70.8%). A previous diagnosis of high BP was reported by only 18.3% of participants, but 65.1% had elevated BP at the time of measurement. Alcohol consumption in the past 30 days among participants (55.4%) was slightly higher than state estimates (48.0%) and similar to national estimates (57.1%). However, heavy drinking (22.2%) and binge drinking (28.8%) were reported at much higher rates than state (5.6% and 15.2%, respectively) and national (6.6% and 18.3%, respectively) estimates. The prevalence of current smoking (21.5%) and quit attempts (48.8%) in the cohort was similar to state (21.8% and 55.0%, respectively) and national (21.2% and 55.7%, respectively) estimates. Likewise, the proportion of EMS providers meeting the Center for Disease Control's activity guidelines (49.6%) was similar to that found in the NC (46.8%) and the general US (48.0%) populations.

CONCLUSIONS

These findings suggest a high prevalence of overweight and obesity, heavy drinking, binge drinking, and high BP among NC EMS personnel. Similar to fire service personnel, these rates are higher than the general US population. As such, they suggest areas where intervention would have the greatest positive impact on the health and performance of the EMS workforce.

Association between maternal adherence to healthy lifestyle practices and risk of obesity in offspring: results from two prospective cohort studies of mother-child pairs in the United States

OBJECTIVE

To examine the association between an overall maternal healthy lifestyle (characterized by a healthy body mass index, high quality diet, regular exercise, no smoking, and light to moderate alcohol intake) and the risk of developing obesity in offspring.

DESIGN

Prospective cohort studies of mother-child pairs.

SETTING

Nurses' Health Study II (NHSII) and Growing Up Today Study (GUTS) in the United States.

PARTICIPANTS

24 289 GUTS participants aged 9-14 years at baseline who were free of obesity and born to 16 945 NHSII women.

MAIN OUTCOME MEASURE

Obesity in childhood and adolescence, defined by age and sex specific cutoff points from the International Obesity Task Force. Risk of offspring obesity was evaluated by multivariable log-binomial regression models with generalized estimating equations and an exchangeable correlation structure.

RESULTS

1282 (5.3%) offspring became obese during a median of five years of follow-up. Risk of incident obesity was lower among offspring whose mothers maintained a healthy body mass index of 18.5-24.9 (relative risk 0.44, 95% confidence interval 0.39 to 0.50), engaged in at least 150 min/week of moderate/vigorous physical activities (0.79, 0.69 to 0.91), did not smoke (0.69, 0.56 to 0.86), and consumed alcohol in moderation (1.0-14.9 g/day; 0.88, 0.79 to 0.99), compared with the rest. Maternal high quality diet (top 40% of the Alternate Healthy Eating Index 2010 diet score) was not significantly associated with the risk of obesity in offspring (0.97, 0.83 to 1.12). When all healthy lifestyle factors were considered simultaneously, offspring of women who adhered to all five low risk lifestyle factors had a 75% lower risk of obesity than offspring of mothers who did not adhere to any low risk factor (0.25, 0.14 to 0.47). This association was similar across sex and age groups and persisted in subgroups of children with various risk profiles defined by factors such as pregnancy complications, birth weight, gestational age, and gestational weight gain. Children's lifestyle did not significantly account for the association between maternal lifestyle and offspring obesity risk, but when both mothers and offspring adhered to a healthy lifestyle, the risk of developing obesity fell further (0.18, 0.09 to 0.37).

CONCLUSION

Our study indicates that adherence to a healthy lifestyle in mothers during their offspring's childhood and adolescence is associated with a substantially reduced risk of obesity in the children. These findings highlight the potential benefits of implementing family or parental based multifactorial interventions to curb the risk of childhood obesity.

Comparison of a physical activity recall questionnaire with accelerometry in children and adolescents with obesity: a pilot study

This study aimed to determine the validity of the Habitual Activity Estimation Scale (HAES) for assessing physical activity (PA) in children and adolescents with severe obesity. Data were obtained from participants (n = 17) in the High Impact Strategies Toward Overweight Reduction in Youth study at the Hospital for Sick Children in Toronto. Objective measurement of PA was recorded with accelerometers and interpreted using counts-per-minute (CPM) cut-points developed for children and adolescents. Self-report measurement of PA was collected using the HAES questionnaire. Pearson correlations revealed HAES significantly overestimated average daily duration of vigorous (+48 ± 64 min, p < 0.001) and moderate-light activity (+114 ± 129 min, p < 0.001) but not inactivity (+38 ± 158 min, p = 0.17). This disagreement may be explained by increased perceived exertion in obese participants when performing PA. Thus, the HAES should not be used to assess PA in obese youth. Further work to validate accelerometer CPM cut-points for obese children and adolescents calibrated to energy consumption and perceived exertion during PA in this group is warranted.

Bone Variables in Active Overweight/Obese Men and Sedentary Overweight/Obese Men

The aim of this study was to compare bone variables in active overweight/obese men and sedentary overweight/obese men. Thirty-seven active overweight/obese men and 45 sedentary overweight/obese men participated in this study. Weight and height were measured, and body mass index was calculated. Body composition and bone variables (bone mineral content [BMC], bone mineral density [BMD], geometric indices of hip bone strength, and trabecular bone score) were measured by DXA. Physical activity level, daily calcium intake, daily protein intake, and sleep duration were measured by validated questionnaires. Maximum oxygen consumption (VO₂ max) was determined by direct measurement while exercising on a medical treadmill. One-repetition-maximum half-squat of the lower limbs was measured using a validated protocol. Body weight and body mass index were higher in sedentary overweight/obese men than in active overweight/obese men. In the whole population (n = 82), VO₂ max (in liter per minute), lean mass, and one-repetition-maximum half-squat were positively correlated to BMC, BMD, and geometric indices of hip bone strength (cross-sectional area and section modulus [Z] of the femoral neck [FN]). After adjusting for body weight using a 1-way analysis of covariance, active overweight/obese men displayed higher whole-body BMC, lumbar spine BMD, total hip BMD, FN BMD, FN cross-sectional area, and FN Z values than sedentary overweight/obese men. In conclusion, the current study suggests that physical activity level positively affects bone variables in overweight/obese men. Optimizing lean mass and muscular strength of the lower limbs can help to prevent osteoporosis in overweight and obese men.

Association of Occupational and Leisure-Time Physical Activity with Aerobic Capacity in a Working Population

Introduction

Objective data on the association of maximal aerobic capacity (VO_2max) with work related physical activity are sparse. Thus, it is not clear whether occupational physical activity (OPA) contributes to an increase of VO_2max. This study examined the association of VO_2max with work and non-work related physical activity in a Swiss working population.

Methods

In this cross-sectional study, a total of 337 healthy and full-time employed adults were recruited. Demographic data, height, weight and BMI were recorded in all subjects. Participants were classified into nine occupational categories (ISCO-88) and merged into three groups with low, moderate, and high OPA. Physical activity was objectively measured by the SenseWear Mini Armband on seven consecutive days (23 hours per day). Participants were regarded as sufficiently active when accumulating ≥30 min of moderate-to-vigorous physical activity per day. VO_2max was evaluated using the multistage 20-meter shuttle run test.

Results

Data of 303 participants were considered for analysis (63% male, age 33 yrs, SD 12). Multiple linear regression analysis (adjusted R² = 0.69) revealed significant positive associations of VO_2max with leisure-time physical activity (LTPA) at vigorous intensity (β = 0.212) and sufficient moderate-to-vigorous physical activity (β = 0.100) on workdays. Female gender (β = -0.622), age (β = -0.264), BMI (β = -0.220), the ratio of maximum to resting heart rate (β = 0.192), occupational group (low vs. high OPA, β = -0.141), and smoking (β = -0.133) were also identified as independent predictors of VO_2max.

Conclusions

The present results suggest that VO_2max is positively associated with LTPA, but not with OPA on workdays. This finding emphasizes the need for employees to engage in sufficient high-intensity physical activity in recreation for maintaining or improving VO_2max with regard to health benefits.

Reliability and Validity of the PAQ-C Questionnaire to Assess Physical Activity in Children

BACKGROUND

Physical activity (PA) assessment by questionnaire is a cornerstone in the field of sport epidemiology studies. The Physical Activity Questionnaire for Children (PAQ-C) has been used widely to assess PA in healthy school populations. The aim of this study was to evaluate the reliability and validity of the PAQ-C questionnaire in Spanish children using triaxial accelerometry as criterion.

METHODS

Eighty-three (N = 46 boys, N = 37 girls) healthy children (age 10.98 ± 1.17 years, body mass index 19.48 ± 3.51 kg/m(2) ) were volunteers and completed the PAQ-C twice and wore an accelerometer for 8 consecutive days. Reliability was analyzed by the intraclass correlation coefficient (ICC) and the internal consistency by the Cronbach's α coefficient. The PAQ-C was compared against total PA and moderate to vigorous PA (MVPA) obtained by accelerometry.

RESULTS

Test-retest reliability showed an ICC = 0.96 for the final score of PAQ-C. Small differences between first and second questionnaire administration were detected. Few and low correlations (rho = 0.228-0.278, all ps < .05) were observed between PAQ-C and accelerometry. The highest correlation was observed for item 9 (rho = 0.311, p < .01).

CONCLUSIONS

PAQ-C had a high reliability but a questionable validity for assessing total PA and MVPA in Spanish children. Therefore, PA measurement in children should not be limited only to self-report measurements.

The Empowering Role of Mobile Apps in Behavior Change Interventions: The Gray Matters Randomized Controlled Trial

BACKGROUND

Health education and behavior change programs targeting specific risk factors have demonstrated their effectiveness in reducing the development of future diseases. Alzheimer disease (AD) shares many of the same risk factors, most of which can be addressed via behavior change. It is therefore theorized that a behavior change intervention targeting these risk factors would likely result in favorable rates of AD prevention.

OBJECTIVE

The objective of this study was to reduce the future risk of developing AD, while in the short term promoting vascular health, through behavior change.

METHODS

The study was an interventional randomized controlled trial consisting of subjects who were randomly assigned into either treatment (n=102) or control group (n=42). Outcome measures included various blood-based biomarkers, anthropometric measures, and behaviors related to AD risk. The treatment group was provided with a bespoke "Gray Matters" mobile phone app designed to encourage and facilitate behavior change. The app presented evidence-based educational material relating to AD risk and prevention strategies, facilitated self-reporting of behaviors across 6 behavioral domains, and presented feedback on the user's performance, calculated from reported behaviors against recommended guidelines.

RESULTS

This paper explores the rationale for a mobile phone-led intervention and details the app's effect on behavior change and subsequent clinical outcomes. Via the app, the average participant submitted 7.3 (SD 3.2) behavioral logs/day (n=122,719). Analysis of these logs against primary outcome measures revealed that participants who improved their high-density lipoprotein cholesterol levels during the study duration answered a statistically significant higher number of questions per day (mean 8.30, SD 2.29) than those with no improvement (mean 6.52, SD 3.612), t97.74=-3.051, P=.003. Participants who decreased their body mass index (BMI) performed significantly better in attaining their recommended daily goals (mean 56.21 SD 30.4%) than those who increased their BMI (mean 40.12 SD 29.1%), t80 = -2.449, P=.017. In total, 69.2% (n=18) of those who achieved a mean performance percentage of 60% or higher, across all domains, reduced their BMI during the study, whereas 60.7% (n=34) who did not, increased their BMI. One-way analysis of variance of systolic blood pressure category changes showed a significant correlation between reported efforts to reduce stress and category change as a whole, P=.035. An exit survey highlighted that respondents (n=83) reported that the app motivated them to perform physical activity (85.4%) and make healthier food choices (87.5%).

CONCLUSIONS

In this study, the ubiquitous nature of the mobile phone excelled as a delivery platform for the intervention, enabling the dissemination of educational intervention material while simultaneously monitoring and encouraging positive behavior change, resulting in desirable clinical effects. Sustained effort to maintain the achieved behaviors is expected to mitigate future AD risk.

TRIAL REGISTRATION

ClinicalTrails.gov NCT02290912; https://clinicaltrials.gov/ct2/show/NCT02290912 (Archived by WebCite at http://www.webcitation.org/6ictUEwnm).

Motivational interviewing and self-determination theory in a web-based computer tailored physical activity intervention: A randomized controlled trial

OBJECTIVE

This study explores whether a web-based physical activity (PA) intervention grounded in self-determination theory (SDT) and motivational interviewing (MI) is more effective and better appreciated than a traditional web-based PA intervention.

DESIGN

A randomized controlled trial was conducted, comparing (1) I Move; a web-based PA intervention based on SDT and MI, (2) Active Plus; a traditional web-based PA intervention and (3) a waiting list control condition.

MAIN OUTCOME MEASURES

Weekly minutes of moderate to vigorous PA and weekly days with ≥30 min PA were measured through self-report at baseline and at 3 and 6 months from baseline.

RESULTS

I Move achieved a small, but significant increase in weekly minutes of moderate to vigorous PA, while Active Plus did not have a significant impact on this outcome. Both interventions were effective in increasing weekly days with ≥30 min PA, whereas Active Plus yielded a greater effect on this outcome.

CONCLUSION

Overall, the web-based PA intervention grounded in SDT and MI did not outperform the traditional web-based PA intervention. Further research should reveal whether this type of intervention is profitable for long-term maintenance of PA levels.

Developmental trajectories of physical activity and television viewing during adolescence among girls: National Growth and Health Cohort Study

Background

Analytic methodology for investigating physical activity patterns over time has been limited. The aim of this study was to demonstrate the group-based trajectory analysis process for identifying developmental physical activity (PA) and television (TV) viewing trajectories and the risk factor of PA trajectories, and for examining a relationship between PA and TV viewing trajectories among adolescent girls.

Methods

Secondary analysis was conducted using the National Growth and Health Study (NGHS) dataset. The NGHS administered the Habitual Activity Questionnaire and TV viewing questionnaire to White and Black girls at age 10, 12, 14, 16, 17, 18, and 19 years. Group-based trajectory analyses were conducted to identify distinct PA trajectories. Race was chosen to present an example of the risk factor analysis and was added as a predictor in the trajectory model. Dual-trajectory analysis was conducted to estimate probabilities of TV viewing trajectory groups conditional on the PA trajectory groups.

Results

A total of 2,155 girls (52 % Black) were included in the data analysis. We identified four PA trajectories: substantially decreasing from high PA (PA group 1, 9.4 %), maintaining moderate PA (PA group 2, 31.6 %), maintaining high PA (PA group 3, 5.8 %), and decreasing from moderate PA (PA group 4, 53.2 %). A significantly lower proportion of Black girls had high PA levels at baseline and maintained their baseline PA than White girls. Most girls who were classified as maintaining high PA (88 %) were also classified as decreasing TV viewing.

Conclusions

A group-based trajectory approach provides new insights about the patterns of maintaining moderate or high levels of PA that exist among adolescent girls. However, a lower proportion of Black girls followed the maintenance patterns than White girls. The behavioral development of PA and TV viewing may be intertwined among adolescent girls.