Predicting Accelerometer-Assessed Estimates of Adolescents' Multidimensional Physical Activity: A Self-Determination Theory Approach.

Based on the tenets in self-determination theory, a dual-process model of motivational processes was tested to predict accelerometer-assessed estimates of adolescents' light physical activity (LPA), moderate to vigorous physical activity (MVPA), and sedentary time. Here, we hypothesized that (a) perceptions of psychological need support for exercise would be positively associated with LPA and MVPA and negatively associated with sedentary time via exercise-related psychological need satisfaction and autonomous exercise motivation and (b) perceptions of psychological need thwarting for exercise would be negatively associated with LPA and MVPA and positively associated with sedentary time via exercise-related psychological need frustration and controlled exercise motivation. Adolescents (N = 338; 234 female) age 11-15 years (M = 12.75, SD = .90) wore an ActiGraph accelerometer for 8 days and completed questionnaires pertaining to the self-determination-theory variables. Results showed psychological need support to indirectly and positively predict LPA and MVPA via psychological need satisfaction and autonomous exercise motivation. Although directly predictive of need frustration and indirectly predictive of controlled motivation and amotivation, the hypothesized effects from psychological need thwarting to the behavioral outcomes were nonsignificant. The current findings highlight the important role that need-supportive environments play in facilitating autonomous exercise motivation and behavior by being conducive to exercise-related psychological need satisfaction.

The acceptability of evidence-informed guidance for parents in talking to their children about weight.

BACKGROUND: Many parents express concern about the impact of talking to children about weight on their self-esteem and wellbeing. The aim of this study was to explore the perceived relevance, utility and acceptability of new guidance for parents on talking to children about weight, developed to apply theory, evidence and expert advice into practice. METHODS: For this qualitative study, parents and public health practitioners (PHPs) were recruited from ten local authorities in England, through the National Child Measurement Programme between June and September 2021. Participants were sent a copy of the guidance document and took part in an interview approximately one week later. Interviews were transcribed verbatim and explored using thematic analysis. RESULTS: 12 parents and 15 PHPs took part, and were similar in their responses reporting the guidance to be acceptable, relevant and helpful. Theme 1 explored how the guidance reduced perceptions of stigma and blame through the perspective and tone that was adopted. Theme 2 explored how the guidance could provide reassurance and increase confidence as a result of case study examples, and specific tips and advice. Theme 3 explored the extent to which participants perceived the advice to be realistic and how it could fit with existing PHP practice. Suggestions for improvement included adapting for relevance for lower income families and providing separate advice for parents of older and younger children. CONCLUSIONS: The guidance was perceived as relevant and needed; it showed potential to reduce parents' negative affect and concerns, and improve confidence around talking to children about weight.

The systematic development of guidance for parents on talking to children of primary school age about weight.

BACKGROUND: The prevalence of overweight and obesity in children is increasing, alongside increases in rates of children's anxiety and worry about their weight. In many countries children's weight is measured, and parents are made aware if a child has been classified as having overweight or obesity. However, many parents are concerned that raising their child's awareness of their weight, and talking to children about their weight could harm their wellbeing. The aim of this project was to develop guidance for parents on constructive ways to talk to children of primary school age about weight when they need to. METHODS: The project followed a mixed-methods design: Phase 1 involved the collation of evidence including (a) two previously published systematic literature reviews to identify the associations between parent-child weight talk, and broader health discussions, and children's wellbeing, (b) interviews with children, and (c) development and refinement of narrative messaging (previously published). In Phase 2 we developed a conceptual model and mapped primary findings to techniques and content within a draft guidance document for parents on talking to children about weight. Phase 3 involved a modified Delphi process with 29 stakeholders to refine and agree a final version. RESULTS: An acceptable draft guidance was agreed following two stages of feedback from Delphi participants. Key areas for debate and adaptation included: encouraging discussion about health and growth with lesser focus on weight; finding ways to reduce stigma and perceptions of blame; emphasising a whole-family approach; inclusive representation of diversity among children and families. CONCLUSIONS: Consensus on the content of guidance for parents on talking to children about weight was achieved through a process of evidence review and stakeholder and expert engagement. The next steps are to measure the impact of the resource on improving the experience of parents and children in communicating about weight.

Influence of obesity prevalence on social norms and weight control motivation: a cross-sectional comparison of the Netherlands and the UK.

This cross-sectional survey study explored associations between perceived bodyweight norms, psychological need satisfaction and motivation for weight control among 500 adult residents of two countries with different overweight/obesity prevalence: the UK (63% prevalence) and the Netherlands (50%). A hypothesised model of the effects of descriptive norms (i.e. perceptions of what is typical for most people) and injunctive norms (i.e. perceptions of what is typically approved by others) on autonomous motivation, mediated through basic psychological need satisfaction, was analysed using structural equation modelling. Descriptive norms did not differ between countries, yet UK adults reported a lower-weight injunctive norm. Perceiving higher bodyweights to be normal negatively predicted motivation to manage one's bodyweight mediated through an undermining effect on psychological need satisfaction. Perceiving higher bodyweights to be normal may have the potential to reduce individual motivation for weight control, but the sensitivity of people's perceptions to objective differences in overweight prevalence appears limited.

Does adjusting for biological maturity when calculating child weight status improve the accuracy of predicting future health risk?

BACKGROUND: The aim of this study was to assess whether adjusting the weight categorisation of children for their biological maturity status could improve the accuracy of predicting weight status and cardiometabolic risk at age 17. METHODS: Data from 1525 participants (787 female) from the ALSPAC study were analysed. Participants' weight status at age 11 was estimated using first standard chronological age and sex adjusted BMI cut-offs, and again using maturity adjusted BMI cut-offs. Each BMI category at age 11 was regressed against cardiometabolic risk score and BMI category at age 17, controlling for sex, ethnicity and socio-economic status. RESULTS: At age 11 years, 22% of boys and 46% of girls who were categorised as overweight or having obesity based on chronological age were re-categorised into a lower BMI category after adjusting for biological maturity. Biologically adjusted BMI categories better predicted BMI category at age 17 compared with non-adjusted BMI categories (∆BIC = - 21.69); the odds of having obesity at age 17 were 18.28 times greater with each increase in BMI category at age 11. Adjusted and non-adjusted BMI status at 11 years showed equivalent accuracy in predicting cardiometabolic risk at age 17; the odds ratio of high cardiometabolic risk was 1.85, with heightened risk in boys, particularly early maturers. CONCLUSION: The traditional method of categorising adolescents into a BMI category may over-predict overweight and obesity, particularly in girls. Adjusting for biological maturity when estimating weight status through calculating adolescents' BMI classification was equivalent to standard approaches in predicting other cardiovascular risk at age 17.

Association between breakfast frequency and physical activity and sedentary time: a cross-sectional study in children from 12 countries.

BACKGROUND: Existing research has documented inconsistent findings for the associations among breakfast frequency, physical activity (PA), and sedentary time in children. The primary aim of this study was to examine the associations among breakfast frequency and objectively-measured PA and sedentary time in a sample of children from 12 countries representing a wide range of human development, economic development and inequality. The secondary aim was to examine interactions of these associations between study sites. METHODS: This multinational, cross-sectional study included 6228 children aged 9-11 years from the 12 International Study of Childhood Obesity, Lifestyle and the Environment sites. Multilevel statistical models were used to examine associations between self-reported habitual breakfast frequency defined using three categories (breakfast consumed 0 to 2 days/week [rare], 3 to 5 days/week [occasional] or 6 to 7 days/week [frequent]) or two categories (breakfast consumed less than daily or daily) and accelerometry-derived PA and sedentary time during the morning (wake time to 1200 h) and afternoon (1200 h to bed time) with study site included as an interaction term. Model covariates included age, sex, highest parental education, body mass index z-score, and accelerometer waking wear time. RESULTS: Participants averaged 60 (s.d. 25) min/day in moderate-to-vigorous PA (MVPA), 315 (s.d. 53) min/day in light PA and 513 (s.d. 69) min/day sedentary. Controlling for covariates, breakfast frequency was not significantly associated with total daily or afternoon PA and sedentary time. For the morning, frequent breakfast consumption was associated with a higher proportion of time in MVPA (0.3%), higher proportion of time in light PA (1.0%) and lower min/day and proportion of time sedentary (3.4 min/day and 1.3%) than rare breakfast consumption (all p ≤ 0.05). No significant associations were found when comparing occasional with rare or frequent breakfast consumption, or daily with less than daily breakfast consumption. Very few significant interactions with study site were found. CONCLUSIONS: In this multinational sample of children, frequent breakfast consumption was associated with higher MVPA and light PA time and lower sedentary time in the morning when compared with rare breakfast consumption, although the small magnitude of the associations may lack clinical relevance. TRIAL REGISTRATION: The International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE) is registered at (Identifier NCT01722500 ).

Effects of a Web-Based, Evolutionary Mismatch-Framed Intervention Targeting Physical Activity and Diet: a Randomised Controlled Trial.

BACKGROUND: This study sought to test the effectiveness of a 12-week, novel online intervention (Evolife) aiming to increase physical activity level (PAL) and reduce energy intake (EI) among overweight/obese adults. The intervention used an evolutionary mismatch message to frame health information in an engaging way, incorporating evidence-based behaviour change techniques to promote autonomous motivation, self-efficacy and self-regulatory skills. METHOD: Men and women aged 35-74 years with a BMI of 25-40 kg/m2 were eligible. Participants were randomised to receive either the intervention (comprising a face-to-face introductory session, 12 weeks' access to the Evolife website and a pedometer) or a control condition (face-to-face introductory session and NHS online health resources). PAL was measured objectively and EI was self-reported using 3-day weighed food records. Secondary measures included BMI, waist circumference and blood pressure. RESULTS: Sixty people met inclusion criteria; 59 (30 intervention) completed the trial (mean age = 50; 56% male). Differences between groups' change scores for PAL and EI were of small effect size but did not reach significance (d = 0.32 and d = - 0.49, respectively). Improvements were found in both groups for PAL (int: d = 0.33; control: d = 0.04), EI (int: d = - 0.81; control: d = - 0.16), waist circumference (int: d = - 0.30; control: d = - 0.17) and systolic blood pressure (int: d = - 0.67; control: d = - 0.28). CONCLUSION: The intervention did not lead to significantly greater improvement in PAL or reduction in EI than a minimal intervention control, although the changes in the intervention group were of meaningful effect size and comparable with positive outcomes in larger intervention trials. TRIAL REGISTRATION: This trail was registered on www.clinicaltrials.gov on 16 January 2017 (appeared online 26 January 2017), reference NCT03032731.

The home electronic media environment and parental safety concerns: relationships with outdoor time after school and over the weekend among 9-11 year old children.

BACKGROUND: Time spent outdoors is associated with higher physical activity levels among children, yet it may be threatened by parental safety concerns and the attraction of indoor sedentary pursuits. The purpose of this study was to explore the relationships between these factors and outdoor time during children's discretionary periods (i.e., after school and over the weekend). METHODS: Data from 462 children aged 9-11 years old were analysed using generalised linear mixed models. The odds of spending > 1 h outdoors after school, and > 2 h outdoors on a weekend were computed, according to demographic variables, screen-based behaviours, media access, and parental safety concerns. Interactions with sex and socioeconomic status (SES) were explored. RESULTS: Boys, low SES participants, and children who played on their computer for < 2 h on a school day had higher odds of spending > 1 h outside after school than girls, high SES children and those playing on a computer for ≥2 h, respectively. Counterintuitive results were found for access to media devices and crime-related safety concerns as both of these were positively associated with time spent outdoors after school. A significant interaction for traffic-related concerns*sex was found; higher road safety concerns were associated with lower odds of outdoor time after school in boys only. Age was associated with weekend outdoor time, which interacted with sex and SES; older children were more likely to spend > 2 h outside on weekends but this was only significant among girls and high SES participants. CONCLUSIONS: Our results suggest that specific groups of children are less likely to spend their free time outside, and it would seem that only prolonged recreational computer use has a negative association with children's outdoor time after school. Further research is needed to explore potential underlying mechanisms, and parental safety concerns in more detail.

Can it be harmful for parents to talk to their child about their weight? A meta-analysis.

Many parents express concern that raising the issue of weight risks harming their child's physical self-perceptions and wellbeing. Such concerns can deter families from engaging with weight management services. This systematic review aimed to investigate the evidence behind these concerns by analysing the association between parent-child weight-talk and child wellbeing. A systematic search of eight databases identified four intervention studies and 38 associative studies. Meta-analysis was only possible for the associative studies; to facilitate more meaningful comparisons, weight-talk was categorized into four communication types and effect size estimates for the association between these and wellbeing indicators were calculated through a random effects model. Encouraging children to lose weight and criticizing weight were associated with poorer physical self-perceptions and greater dieting and dysfunctional eating (effect sizes: 0.20 to 0.47). Conversely, parental encouragement of healthy lifestyles without explicit reference to weight was associated with better wellbeing, but this was only measured in two studies. Of the four intervention studies, only one isolated the effects of parents' communication on wellbeing outcomes, reporting a positive effect. There was no effect of age on the strength of associations, but dysfunctional eating was more strongly associated with parent communication for girls than boys. The findings indicate that some forms of parent-child weight-talk are associated with poor wellbeing, but suggest that this is not inevitable. Encouraging healthy behaviours without reference to weight-control, and positive parental involvement in acknowledging and addressing weight-concern may avoid such outcomes. More longitudinal research is needed to analyse the direction of these effects.

Development and Validation of the Adolescent Psychological Need Support in Exercise Questionnaire.

Grounded within self-determination theory (SDT; Deci & Ryan, 2000; Ryan & Deci, in press), three studies were conducted to develop and psychometrically test a measure of adolescents' perceptions of psychological need support for exercise (viz., for autonomy, competence, and relatedness): the Adolescent Psychological Need Support in Exercise Questionnaire (APNSEQ). In Study 1, 34 items were developed in collaboration with an expert panel. Through categorical confirmatory factor analysis and item response theory, responses from 433 adolescents were used to identify the best fitting and performing items in Study 2. Here, a three-factor nine-item measure showed good fit to the data. In Study 3, responses from an independent sample of 373 adolescents provided further evidence for the nine-item solution as well as for internal consistency, criterion validity, and invariance across gender and social agent (friends, family, and physical education teacher). The APNSEQ was supported as a measure of adolescents' perceptions of psychological need support within the context of exercise.

Can media images of obese people undermine health messages? An experimental study of visual representation and risk perception.

BACKGROUND: Images depicting morbidly obese models [i.e. body mass index (BMI) >40] often accompany media articles about the health risks of being overweight (i.e. BMI 25-30). Little is known about the effect of this mismatch on people's understanding of risk, and perceptions of message relevance. METHODS: In total, 563 participants (291 overweight/obese and 272 healthy weight) were randomly allocated to read a health message about the risk of heart disease posed by being overweight, presented alongside (i) a photo of an overweight model, (ii) a morbidly obese model or (iii) no photo. Between-group differences in the primary outcomes of message relevance, and the body size perceived to be 'at risk', were assessed, and the potential moderating effects of motivation, weight concern and existing risk knowledge explored. RESULTS: Overweight and obese participants in the exaggerated (morbidly obese) image condition interpreted health risks to relate to a larger body size than those who saw no image (F(2, 290) = 4.06, P = 0.02). There was no experimental effect on perceived personal relevance (F(2, 290) = 0.25, P = 0.38). No significant moderation effects were detected, and there was no effect of study condition in healthy weight participants for either outcome. CONCLUSION: The findings suggest that the use of morbidly obese models in messages regarding the health risks of being overweight may undermine the impact of these messages among those who they most aim to reach; the reader may perceive a reduced risk of being 'only' overweight, and that a higher weight is needed for the negative effects of excess weight to occur.

A systematic review to quantitatively evaluate 'Stepping Stones': a participatory community-based HIV/AIDS prevention intervention.

This first independent systematic review examined evidence for the effectiveness of the stepping stones intervention in HIV prevention. To reduce HIV transmission it addresses gender roles and promotes equitable relationships. Biomedical, behavioural and psychosocial outcomes extracted from six databases and 'grey' literature identified eight reports of seven studies (n = 14,630) from India, Gambia, S. Africa, Ethiopia, Angola, Tanzania, Uganda and Fiji. Infection incidence tested in the only RCT showed no significant reduction in HIV, although HSV-2 decreased. Condom use increased (two countries out of eight). Risk reduction results were mixed for declining alcohol misuse (two studies in three) and multiple partners (one in two). Communicating HIV information to partners, family or community improved (three studies from seven). Gender inequity was reduced in India (one in five), but stigma decreased in four studies. Future investigations of diverse cultures and older adults should select high quality biomedical and quality of life measures.

A cluster randomized controlled trial of the be the best you can be intervention: effects on the psychological and physical well-being of school children.

BACKGROUND: The 'Be the Best You Can Be' (BtBYCB) program is a school-based intervention designed to foster positive physical, psychological, and social development via empowering young people to take ownership over their own personal development. The aim of this work is to determine the effectiveness of the BtBYCB program on (i) pupils' well-being, self-perceptions, self-esteem, aspirations, and learning strategies; and (ii) changes in modifiable health-risk behaviors (i.e., physical activity, diet, smoking, and alcohol consumption). METHODS/DESIGN: A two-arm cluster randomized controlled trial employing a wait-list control plus qualitative and mixed-method evaluations was used. Participants were school pupils from Years 7 and 8 (aged 11-13 years). Ten schools located in southwest England were randomly allocated to receive the BtBYCB intervention (n = 5 schools; 711 pupils) or a control condition (i.e., usual Personal, Social, and Health Education classes) (n = 5 schools; 622 pupils). Participants in the intervention condition received a program consisting of (i) a talk from an Olympian/Paralympian; (ii) 11 one-hour teacher-led PSHE classroom sessions in which pupils identified their aspirations, values, and interests and explored and acted on these via activities such as personal development planning, goal-setting, and peer-mentoring; and (iii) participated in a celebration event (e.g., second visit from Olympian/Paralympian and short individual presentations). Data were collected at baseline, post-intervention, and at 3-month follow-up.Focus groups (pupils and teachers) and individual interviews (headteachers) were conducted in the 5 intervention schools to (i) gain an in-depth understanding of mechanisms of change; (ii) explore ways in which the participants' motivation and engagement could be enhanced, and (iii) elicit user-feedback pertaining to how the program, content, and appeal could be improved.A mixed-method approach was used to describe and explain the differing experiences of particular groupings within and across the intervention schools; i.e., those for whom the program was effective, those that experienced little, if any change, and those for whom the program led to an inverse effect. DISCUSSION: The findings of this work will provide insight into the effectiveness of an innovative and child-centered program. The research will inform improvements to the BtBYCB program as well as other interventions targeting child/youth health and wellness. TRIAL REGISTRATION: The trial is registered as Current Controlled Trials ISRCTN99443695.

"Coveting thy neighbour's legs": a qualitative study of exercisers' experiences of intrinsic and extrinsic goal pursuit.

Goals are central to exercise motivation, although not all goals (e.g., health vs. appearance goals) are equally psychologically or behaviorally adaptive. Within goal content theory (Vansteenkiste, Niemiec, & Soenens, 2010), goals are adaptive to the extent to which they satisfy psychological needs for autonomy, competence, and relatedness. However, little is known about what exercisers pursuing different goals are feeling, doing, thinking, and paying attention to that may help to explain the association between goal contents and need satisfaction. Using semistructured interviews and interpretative phenomenological analysis, we explored experiences of exercise among 11 adult exercisers who reported pursuing either predominantly intrinsic or extrinsic goals. Four themes emerged: (a) observation of others and resulting emotions, (b) goal expectations and time perspective, (c) markers of progress and (d) reactions to (lack of) goal achievement. Intrinsic and extrinsic goal pursuers reported divergent experiences within these four domains. The findings illuminate potential mechanisms by which different goals may influence psychological and behavioral outcomes in the exercise context.

Predicting students' physical activity and health-related well-being: a prospective cross-domain investigation of motivation across school physical education and exercise settings.

A three-wave prospective design was used to assess a model of motivation guided by self-determination theory (Ryan & Deci, 2008) spanning the contexts of school physical education (PE) and exercise. The outcome variables examined were health-related quality of life (HRQoL), physical self-concept (PSC), and 4 days of objectively assessed estimates of activity. Secondary school students (n = 494) completed questionnaires at three separate time points and were familiarized with how to use a sealed pedometer. Results of structural equation modeling supported a model in which perceptions of autonomy support from a PE teacher positively predicted PE-related need satisfaction (autonomy, competence, and relatedness). Competence predicted PSC, whereas relatedness predicted HRQoL. Autonomy and competence positively predicted autonomous motivation toward PE, which in turn positively predicted autonomous motivation toward exercise (i.e., 4-day pedometer step count). Autonomous motivation toward exercise positively predicted step count, HRQoL, and PSC. Results of multisample structural equation modeling supported gender invariance. Suggestions for future work are discussed.

The impact of COVID-19 on the eating habits of families engaged in a healthy eating pilot trial: a thematic analysis.

BACKGROUND: The eating habits of children and adults have been impacted by the COVID-19 pandemic, with evidence of increases in snacking and emotional eating, including eating to relieve boredom. We explored the experiences of families with children aged 4-8 years who had recently participated in a healthy eating pilot trial when the first national lockdown began in England. METHODS: Eleven mothers were interviewed in April and May 2020. Interview questions were developed based on the COM-B model of behaviour. Four main themes were constructed using inductive thematic analysis. RESULTS: The first theme related to an initial panic phase, in which having enough food was the primary concern. The second related to ongoing challenges during the lockdown, with sub-themes including difficulties accessing food, managing children's food requests and balancing home and work responsibilities. The perception that energy-dense foods met families' needs during this time led to increased purchasing of (and thus exposure to) energy-dense foods. In the third theme, families described a turning point, with a desire to eat a healthier diet than they had in the early stages of the lockdown. Finally, in the fourth theme, families reported a number of strategies for adapting and encouraging a balanced diet with their children. CONCLUSIONS: Our results suggest that even if parents have the capability (e.g. knowledge) and motivation to provide a healthy diet for their family, opportunity challenges (e.g. time, access to resources, environmental stressors) mean this is not always practical. Healthy eating interventions should not assume parents lack motivation and should be sensitive to the context within which parents make feeding decisions.

Biological maturation as a confounding factor in the relation between chronological age and health-related quality of life in adolescent females.

PURPOSE: To examine the potential confounding effect of biological maturation on the relations between chronological age and health-related quality of life in adolescent British females. METHODS: Biological maturation, chronological age, and health-related quality of life were assessed in 366 British female students in years 7-10 (M = 13.0 years, SD = 0.8). The Kid-Screen 10 was used to assess health-related quality of life. Percentage of predicted adult height attained at measurement was used as an estimate of biological maturation. RESULTS: Pearson product moment correlation demonstrated a statistically significant inverse relation between chronological age and health-related quality of life. This relation was, however, attenuated and non-significant once biological maturation was controlled for. CONCLUSIONS: Researchers studying health-related quality of life in youth should consider and/or control for the potential confounding effect of biological maturation.

Exploring Strategies to Optimise the Impact of Food-Specific Inhibition Training on Children's Food Choices.

Food-specific inhibition training (FSIT) is a computerised task requiring response inhibition to energy-dense foods within a reaction-time game. Previous work indicates that FSIT can increase the number of healthy foods (relative to energy-dense foods) children choose, and decrease calories consumed from sweets and chocolate. Across two studies, we explored the impact of FSIT variations (e.g., different response signals, different delivery modes) on children's food choices within a time-limited hypothetical food-choice task. In Study 1, we varied the FSIT Go/No-Go signals to be emotive (happy vs. sad faces) or neutral (green vs. red signs). One-hundred-and-fifty-seven children were randomly allocated to emotive-FSIT, neutral-FSIT, or a non-food control task. Children participated in groups of 4-15. No significant FSIT effects were observed on food choices (all values of p > 0.160). Healthy-food choices decreased over time regardless of condition (p < 0.050). The non-significant effects could be explained by lower accuracy on energy-dense No-Go trials than in previous studies, possibly due to distraction in the group-testing environment. In Study 2, we compared computer-based FSIT (using emotive signals) and app-based FSIT (using neutral signals) against a non-food control with a different sample of 206 children, but this time children worked one-on-one with the experimenter. Children's accuracy on energy-dense No-Go trials was higher in this study. Children in the FSIT-computer group chose significantly more healthy foods at post-training (M = 2.78, SE = 0.16) compared to the control group (M = 2.02, SE = 0.16, p = 0.001). The FSIT-app group did not differ from either of the other two groups (M = 2.42, SE = 0.16, both comparisons p > 0.050). Healthy choices decreased over time in the control group (p = 0.001) but did not change in the two FSIT groups (both p > 0.300) supporting previous evidence that FSIT may have a beneficial effect on children's food choices. Ensuring that children perform FSIT with high accuracy (e.g., by using FSIT in quiet environments and avoiding group-testing) may be important for impacts on food choices though. Future research should continue to explore methods of optimising FSIT as a healthy-eating intervention for children.

Opportunities and challenges in physical activity research in young people.

The purpose of this opinion piece is to discuss opportunities and challenges to physical activity [PA] research in young people. Two key limitations were identified; (i) the lack of specificity of the types of PA measured and standards in reporting this, and (ii) lack of attention given to ecological frameworks. First, it is argued that a greater specificity of measurement is needed as PA undertaken for different purposes and/or at different levels of intensity is predicted by different determinants, and its uptake mediated by different factors. As such, researchers should carefully define the types and dimensions of physical activity they want to target and choose the appropriate physical activity measure accordingly. Second, given the relatively modest success rates of intensive PA interventions based solely on an individual approach, consideration of ecological research frameworks is advocated, as such approaches that consider multiple levels of influence on individual behaviour have the potential to facilitate far greater understanding of the full range of determinants of PA. Ultimately, it is suggested that low levels of PA among young people might be better addressed through the application of solutions at the local level, and that by tailoring PA programmes to the characteristics of the local environment and population rather than viewing contextual differences as a problem, the efficacy of promising means of intervention could be increased.