Motor skill competence and moderate- and vigorous-intensity physical activity: a linear and non-linear cross-sectional analysis of eight pooled trials.

BACKGROUND: Few studies have examined the relationship between motor skill competence and device-measured physical activity in large samples and none have used non-linear modelling. This study assessed the linear and non-linear associations between motor skill competence and physical activity in children using pooled data from eight studies. METHODS: Cross-sectional ActiGraph accelerometer and motor skills competence data from 988 children (50.8% boys) aged 3-11 years were included. Total, object control and locomotor skill competence were assessed using the Test of Gross Motor Skill Development. Linear mixed models were fitted to examine linear associations between motor skill competence and physical activity. Then, restricted cubic splines models were used to assess potential non-linear relationships. Interactions by sex and age were assessed. RESULTS: There was evidence of positive linear associations between total skill, and object control and locomotor skills, with moderate- and vigorous-intensity physical activity; however, the associations with total skill competence and object control better fitted a non-linear model. Non-linear models indicated associations were positive but relatively weak in the low to mid ranges of TGMD/object control scores but at high ranges (~ > 70 out of 100/ and ~ 35 out of 50) the association strength increased for both moderate- and vigorous-intensity physical activity. There were sex interactions for locomotor skills only, specifically for vigorous activity with boys having a stronger positive association than girls. CONCLUSIONS: There appears to be a threshold for object control skill proficiency that children need to reach to enhance their physical activity levels which provides support for a motor skill "proficiency barrier". This provides a tangible benchmark for children to achieve in motor competence programs.

Scale-up of the Internet-based Professional Learning to help teachers promote Activity in Youth (iPLAY) intervention: a hybrid type 3 implementation-effectiveness trial.

BACKGROUND: Whole-of-school programs have demonstrated success in improving student physical activity levels, but few have progressed beyond efficacy testing to implementation at-scale. The purpose of our study was to evaluate the scale-up of the 'Internet-based Professional Learning to help teachers promote Activity in Youth' (iPLAY) intervention in primary schools using the RE-AIM framework. METHODS: We conducted a type 3 hybrid implementation-effectiveness study and collected data between April 2016 and June 2021, in New South Wales (NSW), Australia. RE-AIM was operationalised as: (i) Reach: Number and representativeness of students exposed to iPLAY; (ii) Effectiveness: Impact of iPLAY in a sub-sample of students (n = 5,959); (iii) Adoption: Number and representativeness of schools that received iPLAY; (iv) Implementation: Extent to which the three curricular and three non-curricular components of iPLAY were delivered as intended; (v) Maintenance: Extent to which iPLAY was sustained in schools. We conducted 43 semi-structured interviews with teachers (n = 14), leaders (n = 19), and principals (n = 10) from 18 schools (11 from urban and 7 from rural locations) to determine program maintenance. RESULTS: Reach: iPLAY reached ~ 31,000 students from a variety of socio-economic strata (35% of students were in the bottom quartile, almost half in the middle two quartiles, and 20% in the top quartile). EFFECTIVENESS: We observed small positive intervention effects for enjoyment of PE/sport (0.12 units, 95% CI: 0.05 to 0.20, d = 0.17), perceptions of need support from teachers (0.26 units, 95% CI: 0.16 to 0.53, d = 0.40), physical activity participation (0.28 units, 95% CI: 0.10 to 0.47, d = 0.14), and subjective well-being (0.82 units, 95% CI: 0.32 to 1.32, d = 0.12) at 24-months. Adoption: 115 schools received iPLAY. IMPLEMENTATION: Most schools implemented the curricular (59%) and non-curricular (55%) strategies as intended. Maintenance: Based on our qualitative data, changes in teacher practices and school culture resulting from iPLAY were sustained. CONCLUSIONS: iPLAY had extensive reach and adoption in NSW primary schools. Most of the schools implemented iPLAY as intended and effectiveness data suggest the positive effects observed in our cluster RCT were sustained when the intervention was delivered at-scale. TRIAL REGISTRATION: ACTRN12621001132831.

The Big Breakfast Study: Chrono-nutrition influence on energy expenditure and bodyweight.

A growing body of evidence highlights the importance of the biological clock as a modulator of energy balance and metabolism. Recent studies in humans have shown that ingested calories are apparently utilised more efficiently in the morning than in the evening and this is manifest through improved weight loss, even under iso-energetic calorie intake. The mechanisms behind this enhanced morning energy metabolism are not yet clear, although it may result from behavioural adaptations or circadian driven variations in physiology and energy metabolism. A major objective of the newly funded Big Breakfast Study therefore is to investigate the mechanistic basis of this amplified morning thermogenesis leading to enhanced weight loss, by exploring behavioural and physiological adaptations in energy expenditure alongside the underlying circadian biology. This report briefly discusses the current research linking meal timing, circadian rhythms and metabolism; highlights the research gaps; and provides an overview of the studies being undertaken as part of the Medical Research Council-funded Big Breakfast Study.

Mothers and teenage daughters walking to health: using the behaviour change wheel to develop an intervention to improve adolescent girls' physical activity.

OBJECTIVES: The majority of adolescent girls fail to meet public health guidelines for physical activity. Engaging mothers in the promotion of physical activity for their daughters may be an important strategy to facilitate behaviour change. The aim of this study was to use the behaviour change wheel (BCW) framework to design the components of an intervention to improve adolescent girls' physical activity. STUDY DESIGN: Cross-sectional study to inform intervention development. METHODS: The BCW framework was used to (1) understand the behaviour, (2) identify intervention functions and (3) select content and implementation options. A circular development process was undertaken by the research team to collectively design the intervention in accordance with the steps recommended by the BCW. RESULTS: The BCW design process resulted in the selection of six intervention functions (education, persuasion, incentivization, training, modelling, enablement) and 18 behaviour change techniques delivered via group-based, face-to-face mode. Behaviour change technique groupings include: goals and planning; feedback and monitoring; social support; shaping knowledge; natural consequences; comparison of behaviour; associations; comparison of outcomes; reward and threat; identity; and, self-belief. CONCLUSIONS: The BCW process allowed an in-depth consideration of the target behaviours and provided a systematic framework for developing the intervention. The feasibility and preliminary efficacy of the programme will be examined.

Dietary outcomes of overweight fathers and their children in the Healthy Dads, Healthy Kids community randomised controlled trial.

BACKGROUND: Few studies have examined dietary intake changes following a weight loss intervention in fathers and the association between father-child dietary intakes. The present study aimed to: (i) evaluate the change in dietary intake in overweight fathers randomised to a family-based lifestyle intervention [Healthy Dads Healthy Kids (HDHK)] versus controls and (ii) investigate whether an association exists between father-child dietary intakes. METHODS: A secondary analysis was conducted of father-child baseline and 3-month post-intervention data (n = 93) collected in the HDHK community randomised controlled trial. Intention-to-treat linear mixed models were used to assess dietary changes by group, time (baseline and 3-month) and the group-by-time interaction. Cohens d was used to determine effect sizes. RESULTS: Significant group-by-time effects (all P < 0.05) favouring fathers in the intervention group were identified for total daily energy intake (-1956 kJ, d = 0.74), total sugars (-45 g, d = 0.63), sodium (-414 mg, d = 0.58) and % energy from nutrient-dense, core foods (+10.1%, d = 0.86), fruit (+2.4%, d = 0.71), vegetarian protein sources (+1.2%, d = 0.57), pre-packed snacks (+1.7%, d = 0.58) and sugar-sweetened beverages (-4.1%, d = 0.58). At baseline, positive correlations were observed between father-child intakes for a number of dietary variables, and significant correlations were observed between father-child change scores for % energy carbohydrate (r = 0.35, P = 0.023), % energy from fruit (r = 0.47, P = 0.002), vegetarian protein sources (r = 0.46, P = 0.002) and frequency of consuming meals with vegetables (r = 0.38, P = 0.012). CONCLUSIONS: The HDHK intervention successfully improved some aspects of father's dietary intakes compared to controls. The fathers' eating patterns also correlated with those of their children for several dietary variables. These novel data suggest that fathers can be targeted as agents of dietary change within obesity prevention and treatment programmes.

A pilot intervention to reduce postpartum weight retention and central adiposity in first-time mothers: results from the mums OnLiNE (Online, Lifestyle, Nutrition & Exercise) study.

BACKGROUND: Postpartum weight retention (PPWR) increases the risk for obesity and complications during subsequent pregnancies. Few interventions have been successful in limiting PPWR in mothers. The present study assessed the effectiveness of the mums OnLiNE (Online, Lifestyle, Nutrition & Exercise) intervention with respect to reducing PPWR and improving diet, physical activity and sedentary behaviour. METHODS: A subsample of first-time mothers enrolled in the Extended Melbourne Infant Feeding Activity and Nutrition Trial (InFANT Extend) completed the nonrandomised mums OnLiNE intervention. Women in the intervention (I) group (n = 28) received access to an online calorie tracking program, smartphone app, three telephone counselling calls with a dietitian and written material. Women in two comparison groups (CI and C2) (n = 48; n = 43) were from the control (C1) and intervention (C2) arms of InFANT Extend and received no additional support. Weight and waist circumference were measured objectively. Written surveys assessed diet and physical activity. Sedentary behaviour was self-reported. Linear and logistic regression assessed changes in outcomes between groups from 9 to 18 months postpartum. RESULTS: Mean PPWR decreased in the (I) group (-1.2 kg) and the C2 group (-1.2 kg), although the changes were not significant. Mean waist circumference for all groups exceeded recommendations at baseline but decreased to below recommendations for women in the (I) group (78.3 cm) and significantly for the (I) group (-6.4 cm) compared to C1 (-1.1 cm; P = 0.002) and C2 (-3.3 cm; P = 0.001). Changes in diet, physical activity or sedentary behaviour were not significant. CONCLUSIONS: The online intervention reported in the present study shows promise with respect to reducing waist circumference in postpartum women. Further evidence of strategies that may improve weight and related behaviours in this target group is needed.

The impact of critical event checklists on medical management and teamwork during simulated crises in a surgical daycare facility.

Although the incidence of major adverse events in surgical daycare centres is low, these critical events may not be managed optimally due to the absence of resources that exist in larger hospitals. We aimed to study the impact of operating theatre critical event checklists on medical management and teamwork during whole-team operating theatre crisis simulations staged in a surgical daycare facility. We studied 56 simulation encounters (without and with a checklist available) divided between an initial session and then a retention session several months later. Medical management and teamwork were quantified via percentage adherence to key processes and the Team Emergency Assessment Measure, respectively. In the initial session, medical management was not improved by the presence of a checklist (56% without checklist vs. 62% with checklist; p = 0.50). In the retention session, teams performed significantly worse without the checklists (36% without checklist vs. 60% with checklist; p = 0.04). We did not observe a change in non-technical skills in the presence of a checklist in either the initial or retention sessions (68% without checklist vs. 69% with checklist (p = 0.94) and 69% without checklist vs. 65% with checklist (p = 0.36), respectively). Critical events checklists do not improve medical management or teamwork during simulated operating theatre crises in an ambulatory surgical daycare setting.

Effects of a 'school-based' physical activity intervention on adiposity in adolescents from economically disadvantaged communities: secondary outcomes of the 'Physical Activity 4 Everyone' RCT.

BACKGROUND/OBJECTIVES: Obesity prevention during adolescence is a health priority. The 'Physical Activity 4 Everyone' (PA4E1) study tested a multi-component physical activity intervention in 10 secondary schools from socio-economically disadvantaged communities. This paper aimed to report the secondary outcomes of the study; to determine whether the intervention impacted on adiposity outcomes (weight, body mass index (BMI), BMI z-score), and whether any effect was moderated by sex, baseline BMI and baseline physical activity level, at 12 and 24 months. SUBJECTS/METHODS: A cluster randomised controlled trial was conducted in New South Wales, Australia. The school-based intervention included seven physical activity strategies targeting the following: curriculum (strategies to maximise physical activity in physical education, student physical activity plans, an enhanced school sport programme); school environment (physical activity during school breaks, modification of school policy); and parents and the community (parent engagement, links with community physical activity providers). Students' weight (kg), BMI and BMI z-score, were collected at baseline (Grade 7), 12 and 24 months. Linear Mixed Models were used to assess between-group mean difference from baseline to 12 and 24 months. Exploratory sub-analyses were undertaken according to three moderators of energy balance. RESULTS: A total of 1150 students (mean age=12 years) provided outcome data at baseline, 1051 (91%) at 12 months and 985 (86%) at 24 months. At 12 months, there were group-by-time effects for weight (mean difference=-0.90 kg (95% confidence interval (CI)=-1.50, -0.30), P<0.01) and BMI (-0.28 kg m-2 (-0.50, -0.06), P=0.01) in favour of the intervention group, but not for BMI z-score (-0.05 (-0.11; 0.01), P=0.13). These findings were consistent for weight (-0.62 kg (-1.21, 0.03), P=0.01) and BMI (-0.28 kg m-2 (-0.49, -0.06), P=0.01) at 24 months, with group-by-time effects also found for BMI z-score (-0.08 (-0.14; -0.02), P=0.02) favouring the intervention group. CONCLUSION: The PA4E1 school-based intervention achieved moderate reductions in adiposity among adolescents from socio-economically disadvantaged communities. Multi-component interventions that increase adolescents' engagement in moderate-to-vigorous physical activity (MVPA) may assist in preventing unhealthy weight gain.

eHealth interventions for the prevention and treatment of overweight and obesity in adults: a systematic review with meta-analysis.

A systematic review of randomized controlled trials was conducted to evaluate the effectiveness of eHealth interventions for the prevention and treatment of overweight and obesity in adults. Eight databases were searched for studies published in English from 1995 to 17 September 2014. Eighty-four studies were included, with 183 intervention arms, of which 76% (n = 139) included an eHealth component. Sixty-one studies had the primary aim of weight loss, 10 weight loss maintenance, eight weight gain prevention, and five weight loss and maintenance. eHealth interventions were predominantly delivered using the Internet, but also email, text messages, monitoring devices, mobile applications, computer programs, podcasts and personal digital assistants. Forty percent (n = 55) of interventions used more than one type of technology, and 43.2% (n = 60) were delivered solely using eHealth technologies. Meta-analyses demonstrated significantly greater weight loss (kg) in eHealth weight loss interventions compared with control (MD -2.70 [-3.33,-2.08], P < 0.001) or minimal interventions (MD -1.40 [-1.98,-0.82], P < 0.001), and in eHealth weight loss interventions with extra components or technologies (MD 1.46 [0.80, 2.13], P < 0.001) compared with standard eHealth programmes. The findings support the use of eHealth interventions as a treatment option for obesity, but there is insufficient evidence for the effectiveness of eHealth interventions for weight loss maintenance or weight gain prevention.

Photoperiodic effects on seasonal physiology, reproductive status and hypothalamic gene expression in young male F344 rats.

Seasonal or photoperiodically sensitive animals respond to altered day length with changes in physiology (growth, food intake and reproductive status) and behaviour to adapt to predictable yearly changes in the climate. Typically, different species of hamsters, voles and sheep are the most studied animal models of photoperiodism. Although laboratory rats are generally considered nonphotoperiodic, one rat strain, the inbred Fischer 344 (F344) rat, has been shown to be sensitive to the length of daylight exposure by changing its physiological phenotype and reproductive status according to the season. The present study aimed to better understand the nature of the photoperiodic response in the F344 rat. We examined the effects of five different photoperiods on the physiological and neuroendocrine responses. Young male F344 rats were held under light schedules ranging from 8 h of light/day to 16 h of light/day, and then body weight, including fat and lean mass, food intake, testes weights and hypothalamic gene expression were compared. We found that rats held under photoperiods of ≥ 12 h of light/day showed increased growth and food intake relative to rats held under photoperiods of ≤ 10 h of light/day. Magnetic resonance imaging analysis confirmed that these changes were mainly the result of a change in lean body mass. The same pattern was evident for reproductive status, with higher paired testes weight in photoperiods of ≥ 12 h of light/day. Accompanying the changes in physiological status were major changes in hypothalamic thyroid hormone (Dio2 and Dio3), retinoic acid (Crabp1 and Stra6) and Wnt/ß-Catenin signalling genes (sFrp2 and Mfrp). Our data demonstrate that a photoperiod schedule of 12 h of light/day is interpreted as a stimulatory photoperiod by the neuroendocrine system of young male F344 rats.

Social cognitive theory and physical activity: a systematic review and meta-analysis.

This review investigated three research questions (i) What is the utility of social cognitive theory (SCT) to explain physical activity (PA)?; (ii) Is the effectiveness of SCT moderated by sample or methodological characteristics? and (iii) What is the frequency of significant associations between the core SCT constructs and PA? Ten electronic databases were searched with no date or sample restrictions. Forty-four studies were retrieved containing 55 SCT models of PA. Methodological quality was assessed using a standardized tool. A random-effects meta-analysis revealed that SCT accounted for 31% of the variance in PA. However, methodological quality was mostly poor for these models. Methodological quality and sample age moderated the PA effect size, with increases in both associated with greater variance explained. Although self-efficacy and goals were consistently associated with PA, outcome expectations and socio-structural factors were not. This review determined that SCT is a useful framework to explain PA behaviour. Higher quality models explained more PA variance, but overall methodological quality was poor. As such, high-quality studies examining the utility of SCT to explain PA are warranted.

School-based obesity prevention interventions: practicalities and considerations.

Pediatric obesity continues to be a major public health concern. Once established it is difficult to treat, therefore well-designed and evaluated prevention interventions are vitally important. Schools have an important role in the prevention of childhood obesity, however, their involvement can be limited by a number of constraints and barriers, which need to be considered when designing interventions. Members of the Prevention Stream of the Australasian Child and Adolescent Obesity Research Network have extensive experience in implementing and evaluating school-based obesity prevention initiatives. Based on their collective experience and evidence from implementation research, the aim of this paper was to highlight six areas to consider when designing, implementing and evaluating obesity prevention initiatives in schools. Further, this paper aimed to provide guidance for overcoming some of the challenges and barriers faced in school-based obesity prevention research. The six key areas discussed include: design and analysis; school-community engagement; planning and recruitment; evaluation; implementation; and feedback and sustainability.

Impact of the 'Healthy Dads, Healthy Kids' lifestyle programme on the activity- and diet-related parenting practices of fathers and mothers.

OBJECTIVES: The aim was to evaluate the impact of the 'Healthy Dads, Healthy Kids' programme on fathers' and mothers' activity- and diet-related parenting practices. METHODS: Overweight/obese fathers (n = 87) and their primary school-aged children (56% boys) were randomized to either (i) 7-week programme (n = 45) or (ii) control group (n = 42). The programme involved four sessions for fathers only and three for fathers/children. Mothers were not directly involved. Parenting practices of both fathers and mothers were measured using the parenting strategies for eating and activity scale at baseline and 14-week follow-up. RESULTS: Intention-to-treat analysis using linear mixed models revealed significant group-by-time effects for fathers' limit setting (P = 0.048, d = 0.36) and reinforcement for multiple lifestyle behaviours (P = 0.001, d = 0.79). No significant intervention effects were found for fathers' control, monitoring, discipline or mothers' parenting practices (P > 0.05). CONCLUSIONS: The Healthy Dads, Healthy Kids programme had a positive impact on some parenting practices for fathers but not mothers.

Can a relatively low-intensity intervention by health professionals prevent weight gain in mid-age women? 12-Month outcomes of the 40-Something randomised controlled trial.

BACKGROUND: Weight gain in perimenopausal women results in increased visceral adipose tissue, leading to metabolic syndrome and associated comorbidities. Despite a high prevalence of weight gain at this life stage, interventions to prevent menopausal obesity are lacking. AIM: To test the effectiveness of an intervention delivered by health professionals using a motivational interviewing (MI) counselling style in preventing weight gain in non-obese (body mass index (BMI) 18.5 and 29.9 kg m(-2)) women in late premenopause. METHODS: In a randomised controlled trial, 54 women (mean (s.d.) age 47.3 (1.8) years; BMI 25.1 (2.4) kg m(-2)) who had menstruated within the preceding 3 months were randomly assigned to an MI intervention (n=28) (five health professional MI counselling sessions) or a self-directed intervention (SDI) (print materials only) (n=26). The primary outcome, body weight (kg) and secondary outcomes (blood lipids, glucose, body fat %, lean mass % and waist circumference) were measured at baseline and postintervention (12 months), and intention-to-treat analysis was conducted. RESULTS: Forty women completed all measures and adhered to all protocols. The weight at 12 months for the MI group of 65.6 kg (95% CI: 64.5; 66.8) was significantly different (P=0.034) from the SDI group of 67.4 kg (95% CI: 66.2; 68.6). When stratified by baseline BMI category, the MI group lost significantly more weight (-2.6 kg; 95% CI: -3.9; -1.2) than the SDI group (-0.1 kg; 95% CI: -1.2; 1.0, P=0.002) for the healthy weight women. The overweight women lost weight regardless of the intervention group, with no between-group difference (-3.5 kg; 95% CI: -6.1, -1.0 and -2.3; 95% CI: -4.1, -0.5, P=0.467). CONCLUSION: This relatively low-intensity intervention, incorporating MI into health professional counselling, not only effectively prevented weight gain but also achieved significant weight loss and decreased diastolic blood pressure. Further refinements are required to optimise outcomes for overweight women.

Changes to dietary intake during a 12-week commercial web-based weight loss program: a randomized controlled trial.

BACKGROUND/OBJECTIVES: The primary aim of this secondary analysis was to compare changes in dietary intake among participants randomized to two versions of a 12-week commercial web-based weight loss program (basic or enhanced) with a waiting-list control. An additional investigation compared changes in dietary intake of successful participants (weight loss ≥5%) with those not successful. SUBJECTS/METHODS: Dietary intake was assessed at baseline and 12 weeks using a validated 120-item semiquantitative food frequency questionnaire. Adults (n=268, 60% female participants, body mass index 32.1 ± 3.9) classified as plausible reporters of energy intake were included in the analyses. Analysis of covariance with baseline observations carried forward for drop-outs (n=38) was used. RESULTS: The basic and enhanced groups significantly increased their percentage of energy contribution from fruits and reduced energy-dense, nutrient-poor foods compared with controls (P<0.001). Successful participants (n=49) reported superior improvements in dietary intake including greater reductions in the mean daily energy intake (P<0.001), the percentage of energy from energy-dense, nutrient-poor foods (-12.0% E vs -4.3% E, P<0.001) and greater increases in the energy contribution from fruits (P<0.001), vegetables (P=0.003) and breads/cereals (P=0.02). CONCLUSIONS: Use of a commercial web-based weight loss program facilitated some improvements in the dietary intake. The enhanced web-based tools appeared not to have generated greater improvements in reported dietary intake, compared with the basic or control groups. Those who achieved a weight loss of ≥5% improved their dietary intake in line with the program recommendations and dietary guidelines. Further research to determine web-based components that may improve success and the reasons why programs are successful for some participants is required.

Neuromedin U partly mimics thyroid-stimulating hormone and triggers Wnt/ß-catenin signalling in the photoperiodic response of F344 rats.

In seasonal animals, photoperiod exerts profound effects on physiology, such as growth, energy balance and reproduction, via changes in the neuroendocrine axes. A key element of the photoperiodic response is the thyroid hormone level in the hypothalamus, which is controlled via retrograde transport of thyroid-stimulating hormone (TSH) from the pars tuberalis of the pituitary. TSH regulates type II deiodinase (Dio2) expression, which transforms inactive thyroid hormone to its active form, via TSH receptors expressed in the ependymal cells of the hypothalamus. In the present study, we hypothesised that a second peptide hormone, neuromedin U (NMU), may play a role in the photoperiodic response alongside TSH because the gene for NMU is also expressed in a strongly photoperiod-dependent manner in the pars tuberalis and its receptor NMU2 is expressed in the ependymal layer of the third ventricle in photoperiod-sensitive F344 rats. Consistent with other studies conducted in nonseasonal mammals, we found that acute i.c.v. injections of NMU into the hypothalamus negatively regulated food intake and body weight and increased core body temperature in F344 rats. At the same time, NMU increased Dio2 mRNA expression in the ependymal region of the hypothalamus similar to the effects of TSH. These data suggest that NMU may affect acute and photoperiodically controlled energy balance through distinct pathways. We also showed that TSH inhibits the expression of type III deiodinase (Dio3) in F344 rats, a response not mimicked by NMU. Furthermore, NMU also increased the expression of genes from the Wnt/ß-catenin pathway within the ependymal layer of the third ventricle. This effect was not influenced by TSH. These data indicate that, although NMU acts with some similarities to TSH, it also has completely distinct signalling functions that do not overlap. In summary, the present study of NMU signalling reveals the potential for a new player in the control of seasonal biology.

Development and evaluation of the Motivation to Limit Screen-time Questionnaire (MLSQ) for adolescents.

OBJECTIVE: The aim of this study was to design and evaluate a brief scale to assess adolescents' motivation to limit their screen-time using a self-determination theory (SDT) framework. METHODS: The development and evaluation of the Motivation to Limit Screen-time Questionnaire (MLSQ) involved three phases. In Phase 1, experts in SDT were asked to review the content validity of the MLSQ items. In Phase 2, adolescent boys (N=342, mean age=12.7 ±.5 years) completed the MLSQ and the factorial validity of the model was explored. In Phase 3, adolescent boys (N=48, mean age=14.3 ± 1.3 years) completed the MLSQ on two occasions separated by 1-week. Phases 2 and 3 were conducted in New South Wales, Australia in 2012. RESULTS: Twenty four SDT experts reviewed the original scale items. Validity coefficients associated with six of the original eight items exceeded the threshold value (V>.68, p<.01). In Phase 2, the revised three-factor (9-items) model provided a good fit to the data (SRMR=.07, CFI=.96). The intraclass correlation (ICC) values were .67 for amotivation and .70 and .82 for controlled and autonomous motivation, respectively. CONCLUSION: This study has provided preliminary evidence for the validity and reliability of the MLSQ in adolescent boys.

Can a Web-based food record accurately assess energy intake in overweight and obese women? A pilot study.

BACKGROUND: Innovative dietary intake measurement tools, such as web-based food records, are becoming increasingly available for self-monitoring. However, the accuracy of this method has not been well studied. This pilot study aimed to evaluate the accuracy of energy intake (EI) estimated by a web-based food record, by comparison with total energy expenditure (TEE) measured by doubly-labelled water (DLW) in overweight and obese women. METHODS: Total energy expenditure (TEE) was assessed in weight stable (±1 kg) women (n = 9), with a mean (SD) age of 34.5 (11.3) years and body mass index of 29.2 (1.4) kg m(-2) over 10 days using the DLW technique. All food and beverages were self-reported for 9-days using a web-based food record and mean daily EI calculated. Food record accuracy was assessed by calculating the absolute (EI - TEE) and percentage (EI/TEE × 100) differences between EI and TEE. Women were identified as under-reporters of EI based on the 95% confidence limits of the expected EI : TEE of 1. RESULTS: The mean (SD) self-reported EI was 8351 (1225) kJ day(-1) [1996 (293) kcal day(-1) ] and TEE was 10 648 (1774) kJ day(-1) [2545 (424) kcal day(-1) ]. The mean (SD) absolute difference in self-reported EI and TEE was -2301 (1535) kJ day(-1) [-550 (367) kcal day(-1) ], representing a mean reporting accuracy of 79.6% (14.1%), with four participants under-reporting EI. CONCLUSIONS: This pilot study highlights the opportunity for the use of the Internet as a novel medium for recording and assessing dietary intake. Although further research is needed in more diverse population groups, the accuracy of web-based food records for assessing EI appears to be consistent with other published dietary intake methods.

Dietary restriction and exercise improve airway inflammation and clinical outcomes in overweight and obese asthma: a randomized trial.

BACKGROUND: Obesity and asthma are associated conditions; however, the mechanisms linking the two remain unclear. Few studies have examined the effects of weight loss on inflammation and clinical outcomes in obese-asthma. OBJECTIVE: To compare the effects of weight loss achieved by dietary restriction, exercise or combined dietary restriction and exercise on airway inflammation and clinical outcomes in overweight and obese adults with asthma. METHODS: Participants (n = 46; 54.3% female, body mass index (mean ± SD) 33.7 ± 3.5 kg/m(2) ) were randomized to complete a 10-week dietary, exercise or combined dietary and exercise intervention. Dual-energy x-ray absorptiometry was performed, the Juniper Asthma Control Questionnaire and Juniper Asthma Quality of Life Questionnaire completed and inflammatory markers, dietary intake and physical activity measured. The trial was registered with the Australian Clinical Trials Registry: ACTRN12611000235909. RESULTS: Retention was 82.6%. Mean ± SD weight loss was 8.5 ± 4.2%, 1.8 ± 2.6% and 8.3 ± 4.9% after the dietary, exercise and combined interventions respectively. Asthma control improved after the dietary (mean ± SD; -0.6 ± 0.5, P ≤ 0.001) and combined interventions (-0.5 ± 0.7, P = 0.040), whereas quality of life improved after the dietary [median (IQR); 0.9 (0.4, 1.3), P = 0.002], exercise [0.49 (0.03, 0.78), P = 0.037] and combined [0.5 (0.1, 1.0), P = 0.007] interventions. A 5-10% weight loss resulted in clinically important improvements to asthma control in 58%, and quality of life in 83%, of subjects. Gynoid adipose tissue reduction was associated with reduced neutrophilic airway inflammation in women [ß-coefficient (95% CI); 1.75 (0.02, 3.48), P = 0.047], whereas a reduction in dietary saturated fat was associated with reduced neutrophilic airway inflammation in males (r = 0.775, P = 0.041). The exercise intervention resulted in a significant reduction to sputum eosinophils [median (IQR); -1.3 (-2.0, -1.0)%, P = 0.028]. CONCLUSION AND CLINICAL RELEVANCE: This study suggests a weight-loss goal of 5-10% be recommended to assist in the clinical management of overweight and obese adults with asthma. The obese-asthma phenotype may involve both innate and allergic inflammatory pathways.