International Journal of Behavioral Nutrition and Physical Activity

ObjectiveTo examine whether teacher education levels and child-teacher ratios are associated with childrens physical activity, psychosocial functioning, and BMI in a large, population-based sample of preschoolers in Stockholm, Sweden. Study designIn a cross-sectional study of 124 public preschools, we analyzed data from two measurement occasions (2020 and 2021) for 3,302 children with accelerometer data, 2,666 with Strengths and Difficulties Questionnaire (SDQ) scores, and 3,518 with measured BMI. Teacher education and child-teacher ratios were obtained from the Swedish National Agency for Education. Mixed-effects regression models accounted for clustering and adjusted for demographic and neighborhood characteristics. ResultsAcross preschools, an average of 31.8% of full-time teachers had a teaching degree, and the mean child-teacher ratio was 5.1 (SD 0.7). No strong associations were observed between teacher education levels or child-teacher ratios and childrens moderate-to-vigorous physical activity (MVPA), inactivity, SDQ, or BMI. Compared with the median, attending preschools with teacher education levels above the 75th percentile was associated with -0.22 minutes (95% CI: -0.84 to 0.40) of daily MVPA, and the 25th percentile with -0.04 minutes (95% CI: -0.77 to 0.69). Similarly, increasing the child-teacher ratio from 5.0 to 5.5 children per teacher corresponded to -0.45 minutes (95% CI: -1.17 to 0.28) of daily MVPA, with negligible differences in SDQ and BMI z-scores. ConclusionsIn this large, representative sample of Stockholm preschoolers, teacher education levels and child-teacher ratios were not associated with childrens physical activity, psychosocial functioning, or BMI, suggesting that factors beyond staffing characteristics may play a more central role in shaping childrens health in preschool settings.

BackgroundStudies examining the associations of intensity-specific leisure time physical activity duration with all-cause, cardiovascular disease (CVD), and cancer mortality are scarce and no quantitative or dose-response meta-analysis has been published. ObjectiveWe examined the associations of moderate, vigorous, and moderate to vigorous leisure time physical activity duration with all-cause, CVD, and cancer mortality, using aggregate and individual participant data. MethodsWe performed a systematic review and meta-analysis of both published and unpublished cohort studies that included data on intensity-specific leisure time physical activity. Hazard ratios (HR) were calculated by comparing high versus low levels of physical activity. We also harmonized and pooled individual participant data from unpublished large cohorts to assess dose-response associations with the same three mortality outcomes, as retrieved from National Death Registries. ResultsA total of 3.36 million participants across 25 cohorts and 17 countries, corresponding to 247,463 all-cause, 70,204 CVD, and 76,294 cancer deaths were included in our aggregate meta-analysis. Compared to low physical activity, the association of high moderate intensity leisure time physical activity with mortality ranged from an HR of 0.84 (95% CI= 0.79, 0.89) for all-cause mortality to 0.90 (0.86, 0.95) for cancer mortality; and vigorous intensity from 0.86 (0.79, 0.93) for all-cause mortality to 0.88 (0.83, 0.91) for cancer mortality. Our pooled individual participant data analysis included 967,184 participants with an average follow-up time of 12.2 (SD= 4.7) years and 60,206 all-cause, 11,525 CVD, and 23,740 cancer deaths. The dose-response analysis showed a general L-shaped association across each outcome. For all-cause mortality, compared to the reference group with no leisure time activity, the minimal and optimal doses of vigorous intensity were 60 mins/week (0.86 [0.84, 0.89]) and 200 mins/week (0.69 [0.67, 0.71]), respectively. For moderate intensity, the corresponding doses were 100 mins/week (0.88 [0.86, 0.90]) and 340 mins/week (0.77 [0.75, 0.79]). ConclusionsOur meta-analysis shows distinct differential associations of moderate and vigorous physical activity with all-cause, cardiovascular, and cancer mortality risk. Improvements in leisure time physical activity approximately equivalent to 60 mins/week of vigorous or 100 mins/week of moderate activity, may be linked with measurable health benefits. Our findings, synthesized uniquely through aggregated and pooled individual participant meta-analyses offer novel evidence to guide decisions on contents of leisure time physical activity focused interventions and preventive guidelines.

BackgroundMost physical activity interventions adopt a one-size-fits-all approach, often developed and tested in higher socioeconomic groups, with little consideration of barriers experienced by women from lower socioeconomic backgrounds. Micropatterns, defined as brief bursts of moderate-to-vigorous incidental physical activity lasting under three minutes, represent a form of everyday movement that requires minimal time, equipment, or planning, making them a promising target for intervention. This randomized controlled study evaluated the feasibility, acceptability and potential effectiveness of a co-designed wearable-based micropatterns intervention aimed at increasing moderate-to-vigorous physical activity (MVPA) among socioeconomically diverse women. MethodsA multi-centre, single-blinded, 6-week randomised controlled feasibility study was conducted among women from Sydney, Australia and Glasgow, UK aged [≥]30 years who self-reported no leisure time physical activity and could comfortably participate in activities of daily living. To ensure socioeconomic diversity, we used quota-based recruitment with area-level and individual-level indicators of socioeconomic status. Participants were randomised to one of three intervention arms; 1) Smartphone application only (APP); 2) smartphone application combined with a wearable device (Fitbit Inspire 3; W-APP); and 3) smartphone application and wearable device, supplemented by a social community component that included two in-person workshops and online forums (W-APP-C). Feasibility was assessed as completion rates of the study and follow-up surveys were conducted to assess the acceptability of the intervention. Wrist-worn accelerometry was collected at pre- and post-intervention to assess the potential effectiveness of the intervention. ResultsForty-three participants (mean age (SD); 54.8 (10.7) years) were recruited across both sites (APP n = 13; W-APP n = 17; W-APP-C n = 13). When taking into consideration individual-level indicators of socioeconomic status including income, number of dependents, and educational attainment, there was diverse representation across low (20.9%), medium (48.8%), and high (30.2%) socioeconomic groups. Completion of the 6-week intervention was high across both intervention sites and all three trial arms (86%). Qualitative feedback from both trial sites indicated high satisfaction, the majority of the participants thought the intervention was enjoyable (97.9%), user-friendly (69.9%), the wearable technology increased motivation to do activity (87.5%), and the community workshops were beneficial (75%). Across all participants, there was an average daily increase of 9.8 (27.8) min/day MVPA following the intervention. The greatest increase in MVPA was observed in the W-APP-C group (15.5 (23.1) min/day), followed by the APP group (11.4 (25.5) min/day), and the W-APP group 2.6 (32.1) min/day. ConclusionsThis multi-centre randomised controlled feasibility trial highlights the feasibility and acceptability of a wearable-based micropattern intervention in women from socioeconomically and culturally diverse backgrounds.

BackgroundTarget trial emulation (TTE) designs provide a framework for strengthening causal inference in observational research, but it is unknown how vulnerable they are to substantial error when the emulated intervention (exposure) measurement is imprecise. In physical activity epidemiology specifically, correcting for confounding via TTE designs but not addressing the large measurement errors arising from self-reports (e.g. questionnaires, which typically capture partial behavioural accounts with very low precision) creates uncertainty about possible dominance of type 2 error biases arising from such novel designs. High-resolution wearables-based methods capture most movement, providing an assessment of physical activity behaviour with substantially less, empirically verified, measurement error. No study has examined how physical activity measurement method influences causal inference in TTE studies. ObjectivesWe applied TTE methodology to sub-samples of the UK Biobank cohort with repeat exposure measurements, to compare the effects of an emulated physical activity intervention on incident CVD risk, when the physical activity exposure was quantified using self-report vs. wearable devices. MethodsThe emulated randomized controlled trial identified physically inactive adults (<150 moderate-to-vigorous physical activity (MVPA) mins/week) who had repeat assessments for wearable and self-reported physical activity. At re-examination, participants were categorised into intervention (adopted the current recommendation of [&ge;]150 MVPA mins/week) or control (remained physically inactive) groups. Participants in each group were propensity score-matched to balance lifestyle behaviours, demographic, and health factors. Cumulative risk for CVD incidence was assessed through cumulative risk curves, hazard ratios, risk ratios, using Fine-Gray subdistribution and Poisson regression models. ResultsThe wearables analytic sample included 490 participants (245 per arm; mean incident CVD follow-up 4.4 years), and the self-report sample included 11,302 participants (5,651 per arm; mean follow-up 6.3 years). In wearables assessments, guideline-adherent participants had markedly lower cumulative CVD risk (cumulative risk = 8.0% vs. 17.0%; hazard ratio [95%CI] = 0.59 [0.36, 0.98]; relative risk = 0.45 [0.28, 0.72]). In contrast, self-report assessments showed near-identical risk trajectories for intervention and control groups (cumulative risk = 21.6% vs. 21.2%; hazard ratio = 0.98 [0.89, 1.08]; relative risk = 0.92 [0.84, 1.00]). Matching the self-report sample to the wearables sample for lifestyle, demographic, and health factors confirmed these findings. ConclusionReliance on self-reported measures of physical activity in TTE studies may obscure emulated intervention effects due to non-differential misclassification, increasing considerably risk of Type II error. Exposure assessment using wearable devices may be essential for valid causal inference in TTE studies of physical activity and CVD risk. Future TTE studies of physical activity exposures should prioritise objective measurements to avoid biased inferences that could affect public health policy and guidelines.

ImportanceExcessive consumption of fast food (FF) is associated with chronic disease. Population-level research on FF outlet visits is now possible with mobility data, however its usefulness as an indicator of FF intake and diet-related disease must be established. ObjectiveInvestigate whether FF outlet visits from mobility data are indicators of self-reported FF intake, obesity, and diabetes, and compared with self-reported intake, equivalent or better indicators of obesity and diabetes. Design, Setting, and ParticipantsA secondary analysis of data from a representative sample of 8,036 adult residents of Los Angeles County (LAC) from the 2011 Los Angeles County Health Survey (LACHS), and mobility data representing all geolocations between October 2016 - March 2017 of 243,644 anonymous and opted-in smartphone users in LAC. Main Outcomes and MeasuresMain outcomes were self-reported FF intake frequency (never, infrequent, moderate, frequent), obesity, and diabetes from LACHS. FF outlet visits were computed as the temporal frequency of FF visits (FF visits/time) and the ratio of visits to FF over all food outlets (FF visits/food), summarized over smartphone users in a neighborhood, scaled from 0-10, and linked to LACHS respondents by census tract. ResultsThe analytic sample included 5,447 LACHS respondents and 234,995 smartphone users with 14,498,850 visits to food outlets. FF outlet visits were significantly associated with self-reported FF intake (reference: never) for both FF visits/time (infrequent: odds ratio [OR], 1.13; 95% CI, 1.06-1.20; frequent: OR, 1.35; 95% CI, 1.28-1.42) and FF visits/food (infrequent: OR, 1.12; 95% CI, 1.06-1.17; frequent: OR, 1.28; 95% CI, 1.22-1.33). FF outlet visits were significantly associated with obesity (FF visits/time: adjusted OR [AOR], 1.16; 95% CI, 1.12-1.21; FF visits/food: AOR, 1.13; 95% CI, 1.10-1.17) and diabetes (FF visits/time: AOR, 1.15; 95% CI, 1.09-1.21; FF visits/food: AOR, 1.11; 95% CI, 1.07-1.16), adjusted for sociodemographic factors. Models of the association between FF outlet visits and obesity or diabetes had better fits than between self-reported FF intake and obesity or diabetes. Conclusions and relevanceThis study illustrates that population-scale mobility data provide useful, passively-collected indicators of FF intake and diet-related disease within large, diverse urban populations that may be better than self-report intake. Key PointsO_ST_ABSQuestionC_ST_ABSDo visits to fast food outlets observed in mobility data provide meaningful measures of fast food intake, and when compared with self-reported intake, equivalent or better indicators of diet-related disease? FindingsIn this cross-sectional Los Angeles County study from a survey of 8,036 adults and mobility data from 243,644 smartphone users with 14.5 million food outlet visits, neighborhood-level features representing visits to fast food outlets were significantly associated with self-reported fast food intake, significantly associated with obesity and diabetes, and were a better predictor of these diseases than self-reported fast food intake. MeaningMeasures of food behaviors observed in population-scale mobility data can provide meaningful indicators of food intake and diet-related diseases, and could complement existing dietary surveillance methods.

IMPORTANCEMovement behaviours (e.g. sedentary behaviour (SB), moderate and vigorous physical activity (MVPA), light intensity physical activity (LIPA) and sleep) are linked to cognition, yet the relative importance of each component is unclear, and not yet explored with compositional methodologies. OBJECTIVETo examine how time spent in one behaviour (e.g. SB, MVPA, LIPA, sleep) relative to all others is associated with overall cognition, including executive function and memory. DESIGN, SETTING, AND PARTICIPANTSThe 1970 British Cohort Study (BCS70) is an ongoing prospective birth cohort study of adults born in England, Scotland and Wales in a single week. At age 46, participants wore an accelerometer device and completed cognitive screening. Linear regression was used to examine cross-sectional associations between movement behaviours and cognitive scores, using a compositional approach. Isotemporal substitution was performed to model the effect of reallocating time between components of daily movement on cognition. EXPOSURESA thigh-mounted activPAL accelerometer device was worn without removal for one week. Daily time in SB, MVPA, LIPA and sleep were derived using a validated processing algorithm. MAIN OUTCOMES AND MEASURESStandardised scores of executive function (letter cancellation and verbal fluency), memory (immediate and delayed wordlist recall) and a composite score were derived from computer administered cognitive tasks. RESULTSThe sample comprised 4,481 participants (52% female). Time in MVPA relative to SB, LIPA and sleep was positively associated with cognition after adjustments for education and occupational physical activity, but additional adjustment for health status attenuated associations. SB relative to all other movements was robustly positively associated with cognition. Modelling time reallocation between components revealed a higher cognition percentile after MVPA theoretically replaced just 9 minutes of SB (+1.31; 95% CI: 0.09, 2.50), 7 minutes of LIPA (+1.27; 0.07, 2.46) or 7 minutes of sleep (+1.20; 0.01, 2.39). CONCLUSIONS AND RELEVANCERelative to time spent in other behaviours, more time spent in MVPA and SB was associated with higher cognitive scores. Displacement of MVPA time, given its smaller relative amount, appear most deleterious. Efforts should be made to preserve MVPA time, or reinforce it with time taken from other behaviours.

ImportancePhysical activity guidelines are predominantly based on questionnaire-based studies measuring only longer planned physical activity bouts (>10-15 continuous minutes). To date, short intermittent bouts of physical activity that may be beneficial for health ("micropatterns"), have counted very little towards physical activity guidelines (currently 150-300 minutes of moderate or 75-150 minutes of vigorous intensity activity per week). ObjectiveWe examined all-cause and cardiovascular disease (CVD) mortality associations of wearable device-captured activity accumulated through intermittent moderate to vigorous (IMVPA; [&le;]3 min) and vigorous (IVPA; [&le;]1 min) intensity bouts, by guideline adherence for a) active adults (eg. doing at least 150 mins/wk of moderate or 75 mins/wk of vigorous intensity physical activity), and b) inactive adults (not meeting the above amounts). DesignProspective cohort study SettingUK Biobank Participants62,899 adults (mean age 61 years, 55.7% female) with wrist-worn accelerometer data, followed up for an average of 8.0 (SD= 0.9) years ExposuresIntermittent moderate-vigorous (IMVPA; [&le;]3 min) and vigorous (IVPA; [&le;]1 min) intensity bouts; stratified by participants meeting and not meeting physical activity guidelines. Main outcomes and measuresAll-cause and CVD mortality obtained through linkage with the National Health Service (NHS) Digital of England and Wales or the NHS Central Register and National Records of Scotland. Cox restricted cubic spline regression were used to assess the dose-response associations. ResultsThere were 1,583 all-cause and 442 CVD deaths among 62,899 adults (mean age 61 years, 55.7% female). Micropatterns accrued IMVPA and IVPA showed linear beneficial dose response associations in both the inactive and active groups. We observed a 1.4 to 2.0-fold lower mortality risk among inactive compared to active adults. For all-cause mortality, a median 4.0 minutes/day of IVPA was associated with a hazard ratio (HR) of 0.40 [0.32, 0.52] in inactive adults and 0.74 [0.58, 0.95] in active adults, compared to not doing any IVPA. For CVD mortality, a median of 13.0 minutes/day of IMVPA was associated with an HR of 0.32 [0.22, 0.51] in inactive adults and 0.53 [0.37, 0.78] in active adults. Analogous patterns of dose-response were present when adherence to guidelines was assessed using questionnaire-based data that only considered continuous activity bouts lasting at least 10 minutes. Conclusions and relevanceAmong participants not meeting guidelines, intermittent moderate-vigorous physical activity showed stronger beneficial dose-response association with all-cause and CVD mortality, compared to active adults, highlighting potential health benefits from brief activity bursts for less active adults. Considering such activity patterns are hardly represented in the evidence used to develop current guidelines, our findings support the transition of future guidelines towards wearables-informed evidence.

BackgroundIt is unclear whether intervention effects on school-aged childrens physical activity differ across specific periods of the week or day. This study aimed to assess the time-specific intervention effects on accelerometer-measured physical activity in primary school children. MethodsThis was a nested study in a cluster-randomized controlled trial conducted from September 2018 to June 2019 in China. The intervention group included 4 schools (119 children) and the control group included 4 schools (99 children) in Beijing. The obesity prevention intervention engaged schools and families to improve childrens physical activity. Outcome measures included accelerometer-assessed intensity and amounts of physical activity within specific periods of a week (weekday/weekend day) or a day (in-school/out-of-school periods). Linear mixed models were used to estimate intervention effects. Subgroup analyses were also conducted to examine potential moderators including sex, age, body mass index, physical activity, and accelerometer compliance. ResultsThe intervention lead to an increase in time engaged in moderate-to-vigorous physical activity (MVPA) within in-school periods of a day (adjusted mean difference: 0.54 minutes/hour; 95% confidence interval: 0.13, 0.94, P = 0.012) but it did not improve physical activity within out-of-school periods (P > 0.05) compared with the control group. There was no difference in the effect size across most of the moderators except for age, as younger children appeared to benefit more from the intervention in the improvement of in-school MVPA (Pinteraction = 0.035). No between-group differences were observed in physical activity within the whole weekday or weekend day (P > 0.05). ConclusionThe intervention effectively increased MVPA within in-school periods but did not improve out-of-school physical activity. Findings support the tailoring of intervention components to specific periods of a day to improve school-aged childrens whole pattern of physical activity. TRIAL REGISTRATIONClinicalTrials.gov Identifier: NCT03665857

IntroductionWhole system approaches to public health challenges such as low physical activity levels have the potential to create sustained behaviour change at a population level and tackle health inequalities. However, there is currently little evidence of the nature or effectiveness of adopting whole system approaches. This study evaluated whether a whole system physical activity intervention (JU:MP), was effective at improving physical activity in five- to eleven-year-olds. MethodsA before and after controlled study with two-arms (JU:MP intervention and control), was conducted in Bradford, UK with data collected at baseline and 24-months follow-up. Habitual physical activity was measured via accelerometry. The primary outcome was difference in moderate-to-vigorous intensity physical activity (MVPA) between groups at 24-months. Secondary outcomes included: sedentary time (ST), counts per minute (CPM), BMI z-score, waist circumference, social, emotional and behavioural health, and quality-of-life. An exploratory analysis compared intervention effects between sub-groups. Results1,453 children were recruited. 330 children with valid wear-time at baseline and 24- months (JU:MP group n=175, control group n =155) were included in the final analysis of physical activity outcomes. The JU:MP group improved levels of MVPA (+4.99 minutes/day, (CI = 1.01, 8.96), standardised mean difference (SMD) = 0.29), ST ( -8.69 minutes/day, CI = -16.76, -0.61), SMD = -0.20) and CPM (+32.72, CI = 5.93, 59.53, SMD = 0.28) compared to controls. There were minor differences between groups in all secondary outcomes, favouring the JU:MP group. Exploratory sub-group analysis revealed that MVPA improved for boys (+7.34 minutes/days, CI = 0.70, 13.99, SMD = 0.36) and South Asian heritage children (+7.20 minutes/day, CI = 1.67, 12.72, SMD = 0.52) in the JU:MP group compared to the control group. Conclusion: whole system approaches hold considerable promise for addressing childrens levels of physical activity at scale, whilst also tackling inequalities. Key messagesO_ST_ABSWhat is already known on this topicC_ST_ABSThe physical activity levels of children are influenced by complex political, environmental and social systems. The World Health Organisation and the International Society of Physical Activity and Health both advocate for whole system change to support population level improvements in physical activity. What the study addsThis study provides evidence that improving population levels of physical activity in children can be achieved by taking a whole system approach. How this study might affect research practice or policyThis study can give confidence to policy makers and practitioners who are considering or continuing to take a whole system approach to improve physical activity for populations at greatest need.

BackgroundResearch on the health effects of stepping intensity in free-living environments is limited and inconclusive. Inconsistent use of stepping intensity estimation metrics could explain current equivocal results. We aimed to examine and compare a range of different cadence-based metrics in terms of their multivariable-adjusted associations with all-cause (ACM) cardiovascular disease (CVD), cancer and physical-activity (PA)-related cancer mortality. MethodsThis prospective cohort study included participants with valid wrist-worn accelerometer data from the UK Biobank. We estimated stepping intensity using ten different cadence-based metrics, including eight peak-cadence metrics (defined as averaged steps / min of the highest but not necessarily consecutive minutes) that most of whom have appeared in prior literature, plus two non-peak-cadence metrics: 1) average daily cadence, defined as steps/accelerometer wearing mins, and 2) average cadence of purposeful steps, defined as averaged steps / min of minutes with [&ge;]40 steps. We rescaled each metric into a standardised cadence scale with mean of 0 and standard deviation (SD) of 1, using (absolute-mean)/SD. We compared the dose-response associations of each stepping intensity estimation metrics with mortality outcomes using previously published modelling involving Cox-restricted-cubic-spline model, presented as overlay plots on standardised and absolute cadence scales. ResultsAmong 70,336 participants (age [SD], 61.6 [7.8] years; female, 40,933 [58%]) followed up for a median of 8.0 years, all cadence-based metrics, besides the average cadence of purposeful steps, exhibited a comparable beneficial dose-response association with ACM/CVD/cancer mortality, with 95% CI largely overlapped (e.g., at -0.2 standardised steps/min, the hazard ratio (HR) of ACM for peak 1- and peak 30-min cadence were: 0.72, 95%CI [0.65, 0.82] and 0.66 [0.60, 0.73], respectively). The average cadence of purposeful steps only did not show dose-response associations with mortality outcomes (e.g., the HR that corresponds to the standardised median for the average cadence of purposeful steps in ACM was 0.98 [95% CI: 0.86, 1.12]. ConclusionBesides the average cadence of purposeful steps, all stepping intensity estimation metrics demonstrated comparable beneficial dose-response associations with mortality of all-cause, CVD and cancer, suggesting these cadence-based metrics may be used interchangeably for estimating associations of free-living stepping intensity with health outcomes and applied in different research scenarios accordingly.

BackgroundPhysical activity is a key modifiable determinant of health, yet current guidelines primarily emphasize moderate-to-vigorous physical activity and provide limited guidance on other actionable dimensions such as daily step count and sedentary time. The growing availability of wearables enables high-resolution measurement of these metrics and assessment of their associations with clinical outcomes. MethodsMinute-level wearable data from adult participants of All of Us between 2015-2023 were used to calculate step count and sedentary time. Patterns of step count and sedentary behavior were assessed across temporal scales, U.S. states, and sociodemographic groups. Phenome-wide association (PheWAS) and dose-response analyses were conducted to evaluate associations with incident disease. ResultsAmong 50,300 participants (68% female, 71% White, median age 55 years), 19,845,612 person-days of wearable monitoring over a median follow-up of 13 months were included in this analysis. Step counts peaked at midday with weekly highs on Saturdays and seasonal highs in May, while sedentary time was highest in midafternoon and winter. Higher step counts and lower sedentary time were observed among males, individuals with higher income and education, and residents of the Northeast, upper Midwest, and West Coast. In PheWAS (n=31,446), higher step count and lower sedentary time were associated with lower risk of multiple diseases, including obesity, cardiometabolic risk factors, and mood and anxiety disorders. Dose response analyses demonstrated heterogeneous relationships across disease groups, with cardiovascular benefits plateauing beyond 9,000-10,000 steps/day and below 600-640 minutes/day of sedentary time. ConclusionsIn this nationwide cohort of U.S. adults, wearable-derived physical activity and sedentary behavior showed distinct temporal and geographic patterns with significant disease-specific associations with clinical outcomes. These findings support the use of longitudinal high-resolution wearable data for advancing personalized guidelines of physical activity and sedentary behavior.

BackgroundThe consumption of ultra-processed foods (UPF) has been proposed as a key driver of the global rise in non-communicable diseases. Evidence from several countries suggests that adolescents are the highest consumers. This study examined UPF consumption in a representative sample of UK adolescents. MethodsWe used data from 4-day food diaries from adolescents (11-18y) in the UK National Diet and Nutrition Survey (2008/09-2018/19) (n=3,270). UPF were identified using the NOVA classification. We estimated the percentage of Total Energy Intake (%TEI) and the absolute weight (grams). Linear regression models quantified differences in UPF consumption across survey years and its association with participants individual characteristics. ResultsMean UPF consumption was 861 (SD 442) g/d and this accounted for 65.9% (SD 13.4%) of TEI. Between 2008 and 2019, mean UPF consumption decreased from 996 to 776 g/d [-211 (95%CI: -302;-120)] and from 67.7% to 62.8% of TEI [-4.8% (95%CI:-8.1;-1.5)]. Higher %TEI was consumed by adolescents with lower socioeconomic status; white ethnicity and living in England North. A higher weight of UPF consumption was associated with being male, white, age 18y, having parents with routine or manual occupation, living in England North, and living with obesity. Discussion and conclusionAverage energy intake from UPF has decreased over a decade in UK adolescents. We observed a social and regional patterning of UPF consumption, with higher consumption among adolescents from lower socioeconomic backgrounds, from a white ethnicity and living in England North. Our findings suggest a relationship between individual characteristics and UPF consumption by UK adolescents.

BackgroundSedentary behaviour has been the focus of considerable clinical, policy and research interest due to its detrimental effects on health and wellbeing. This systematic review aims to (1) develop a more precise description of different categories of interventions that aim to reduce sedentary time in adults by identifying specific components that form an intervention; (2) explore the effect of different categories of interventions in reducing time spent sedentary in adults. MethodsTen electronic databases, websites of relevant organisations (e.g. the Sedentary Behaviour Research Network), and relevant reviews were searched. Inclusion criteria: Randomised controlled trials (RCTs), including cluster and randomised cross-over trials, in the adult population (clinical and non-clinical). Any study including a measure of sedentary behaviour was included even if reducing sedentary behaviour was not the primary aim. Exclusion criteria: Interventions delivered in schools, colleges, or workplaces; studies investigating the immediate effects of breaking up sitting time as part of a supervised (usually laboratory-based) intervention. Two review authors conducted data extraction and quality assessment (GRADE approach). ResultsSearches identified 39,223 records, of which 85 studies met the inclusion criteria and were included in the review. Interventions shown to significantly reduce time spent sedentary were those which incorporated the provision of information, education, or support (advice/recommendations), in conjunction with either counselling (mean difference: -52.24 minutes/day; 95% CI: -85.37 to -19.10) or a form of structured/prescribed physical activity (standardised mean difference: -0.15; 95% CI: -0.23 to -0.07). However, this positive effect was not maintained at follow-up. No interventions were shown to break up prolonged sitting. ConclusionsThis review presents a novel way of categorising interventions according to the types of components they comprised. There is evidence that interventions might be effective in reducing time spent sedentary immediately post-intervention. There were limited studies measuring sustained behaviour change.

BackgroundDiet plays an important role in the development of cardiovascular diseases and in maintaining sustainable planetary boundaries. The EAT-Lancet Planetary Health Diet could potentially provide co-benefits for human and environmental health, yet evidence on the association between adherence to the EAT-Lancet Planetary Health Diet and risk of cardiovascular events and environmental impact is limited. MethodsWe investigated the association between adherence to the EAT-Lancet diet and coronary heart disease (CHD) and stroke risk, and with greenhouse gas (GHG) emissions, land use, and dietary species richness (DSR). We included 364,745 adult men and women participating in the European Prospective Investigation into Cancer and Nutrition (EPIC) study. Food frequency questionnaires were used to create a score reflecting adherence to the EAT-Lancet diet (EAT-Lancet diet-score), ranging from 0 (no adherence) to 140 (complete adherence). A (pro-) vegetarian version of the score, the EAT-Lancet dietVV-score, was also created, which rewarded low to no consumption of all animal-based foods. Cox proportional hazard regressions were used to study the association of adherence to the EAT-Lancet diet with CHD and stroke incidence. Linear regression analyzed the association with GHG emissions, land use, and DSR. FindingsOver a median follow-up of 12{middle dot}8 years, we identified 12,690 CHD and 7,088 stroke cases. After multivariable adjustment, those most adherent to the EAT-Lancet diet had lower risk of incident stroke (HRQ5vsQ1: 0{middle dot}59, 95%CI = 0{middle dot}54 to 0{middle dot}64), and of incident CHD for those younger than 60 years old at baseline (HRQ5vsQ1: 0{middle dot}86, 95%CI = 0{middle dot}79 to 0{middle dot}93). High adherence to the EAT-Lancet diet reduced GHG emissions by 1{middle dot}7% (95%CI = -1{middle dot}9 to -1{middle dot}5) and land use by 6{middle dot}2% (95%CI = -6{middle dot}4 to -5{middle dot}9). The EAT-Lancet dietVV-score further reduced GHG emissions and land use by 14{middle dot}3% (95%CI= -14{middle dot}5 to -14{middle dot}0) and 18{middle dot}8% (95%CI = -19{middle dot}0 to -18{middle dot}5), respectively, when comparing extreme quintiles, while hazard ratios for CHD and stroke remained unchanged. Those most adherent to the EAT-Lancet diet consumed 16{middle dot}1% (95%CI = 15{middle dot}9 to 16{middle dot}4) more plant species and 19{middle dot}7% (95%CI = -20{middle dot}11 to -19{middle dot}40) fewer animal species. InterpretationHigher adherence to the EAT-Lancet diet was associated with co-benefits for both cardiovascular outcomes and environmental indicators, including dietary species richness. Lower GHG emissions and land use were achieved by further reducing consumption of animal-based products. FundingThe coordination of EPIC-Europe is financially supported by the International Agency for Research on Cancer (IARC) and also by the Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London which has additional infrastructure support provided by the NIHR Imperial Biomedical Research Centre (BRC). Exposure indicators were calculated with financial support of the Wereld Kanker Onderzoek Fonds (WKOF), as part of the World Cancer Research Fund International grant programme (IIG_FULL_2020_034). Research in contextO_ST_ABSEvidence before this studyC_ST_ABSThe authors considered all evidence available to them on the EAT-Lancet Planetary Health Diet, published up until May 2024. The authors searched for relevant articles on the association between adherence to the diet and cardiovascular outcomes and environmental indicators. Studies investigating the association between the diet and outcomes not of interest in this study were not considered. We restricted to evidence from prospective cohort studies with similar analyses and methodology, thereby excluding studies modelling the environmental impact. We found two research articles that explored the association of EAT-Lancet Planetary Health Diet with both cardiovascular outcomes and environmental impact, four that only assessed the association with cardiovascular outcomes, and three only focused on environmental indicators. We found no studies on the association between adherence to the EAT-Lancet Planetary Health Diet and food biodiversity. These studies spanned across varied population groups, focused on different cardiovascular endpoints and reported inconclusive evidence. This also streams from the use of different scores and indices to measure adherence to the EAT-Lancet Planetary Health Diet, which strongly influences evidence on risk estimates. Similarly, evidence on greenhouses gas emissions and land use are hindered by the use of different methodologies to calculate the associated environmental impact of foods and beverages. Added value of this studyThis study benefits from the use of a large pan-European cohort, which used a standardized nutrient and food database to determine individual dietary intake, as well as environmental data derived by Life Cycle Assessment analyses validated at the European level. The use of two diet scores--one representing an omnivorous version of the EAT-Lancet Planeatry Health Diet (EAT-Lancet diet-score) and the other representing a plant-based variation (EAT-Lancet dietVV-score) --demonstrates that greater environmental benefits can be achieved with the EAT-Lancet dietVV-score by further restricting consumption of animal-based products, without impacting the benefits on human health. The study adds to the current evidence on the impact of the EAT-Lancet Planetary Health Diet on both cardiovascular health and environmental well-being, and additionally supports evidence of an association between adherence to the EAT-Lancet Planetary Health Diet and food biodiversity. The association with food biodiversity adds an important complementary measure of health and sustainability to the current body of evidence on co-benefits of the EAT-Lancet Planetary Health Diet. Implications of all the available evidenceOur findings substantiate the co-benefits of adherence to the EAT-Lancet Planeatry Health Diet found in previous studies for cardiovascular health and environmental indicators, with evidence from a large pan-European population-based study. This research study found evidence that adherence to the EAT-Lancet diet was associated with lower risk of stroke across the whole population and with lower risk of CHD among those younger than 60 years old. This study also highlights the impact of the ways in which we operationalise adherence to the EAT-Lancet Planetary Health Diet, emphasizing its importance for comparing studies and developing national policies.

BackgroundA recent meta-analysis suggested that using physical activity calorie equivalent (PACE) labels results in people selecting and consuming less energy. Only one included study was conducted in a naturalistic setting, in four convenience stores. The current study aimed to estimate the effect of PACE labels on energy purchased in worksite cafeterias. Methods and findingsA stepped-wedge randomised controlled trial to test the effect of PACE labels (which include kcal content and minutes of walking required to expend the energy content of the labelled food) on energy purchased. The setting was ten worksite cafeterias in England, which were randomised to the order in which they introduced PACE labels on selected food and drinks following a baseline period. The study ran for 12 weeks with over 250,000 transactions recorded on electronic tills. The primary outcome was total energy (kcal) purchased from intervention items per day. The secondary outcomes were: energy purchased from non-intervention items per day, total energy purchased per day, and revenue. Regression models showed no evidence of an overall effect on energy purchased from intervention items, -1.3% (95% CI -3.5% to 0.9%) during the intervention. Of the 10 cafeterias, there were null results in five, significant reductions in four, and a significant increase in one. There was also no evidence for an effect on energy purchased from non-intervention items, -0.0% (95% CI -1.8% to 1.8%), and no clear evidence for total items -1.6% (95% CI -3.3% to 0.0%). Revenue increased during the intervention, 1.1% (95% CI 0.4% to 1.9%). Study limitations include using energy purchased and not energy consumed, and access only to transaction-level sales, rather than individual-level data. ConclusionOverall, the evidence was consistent with PACE labels not changing energy purchased in worksite cafeterias. There was considerable variation in effects between cafeterias, suggesting potentially important unmeasured moderators. Trial registrationThe study was prospectively registered on ISRCTN (date: 30.03.21; ISRCTN31315776).

ImportanceEating from out-of-home food outlets (OHFO) is common and linked to poor dietary quality, weight gain, and obesity. In response, England implemented mandatory calorie labelling regulations in April 2022 to encourage reformulation and reduce calorie consumption. Few studies have examined the impact of a national calorie labelling policy on OHFO menus. ObjectiveExamine pre-post changes in energy content of menu items from large OHFO in England after mandatory calorie labelling. Design, Setting, and ParticipantsObservational study using data from MenuTracker, a longitudinal database of online menus. Data were collected in September 2021 (pre-policy) and September 2022 (post-policy) from large OHFO in England. 15,057 pre-policy and 15,988 post-policy menu items were included from 78 large OHFO chains present in both periods. InterventionImplementation of mandatory calorie labelling on menus of large OHFOs in England. Main Outcomes and MeasuresMean energy content (kcal) of menu items, examined overall and by food group and chain type. Changes in energy content for removed, continuous, and new items to assess reformulation. ResultsOverall, a reduction of 9 kcal (95% CI: -16 to -1) in mean energy content was observed post-policy. Significant reductions per item in beverages (-36 kcal), burgers (-103 kcal), and mains (-30 kcal). By chain type, significant reductions per item in pubs, bars, and inns (-52 kcal), restaurants (-23 kcal), and entertainment venues (-49 kcal). Changes driven by removal of higher kcal items (458 kcal, 95% CI: 394 to 523) and addition of lower kcal items (434 kcal, 95% CI: 370 to 499). No significant change in energy content for continuously available items, indicating limited evidence of reformulation. Conclusions and RelevanceThe 2022 mandatory calorie labelling policy in England led to a small reduction in mean energy content of menu items, driven by removal of higher calorie items and addition of lower calorie items. Elsewhere, we did not find evidence of changes in kcal purchased or consumed, suggesting these menu changes did not focus on the most commonly consumed items. Further research is needed to evaluate longer-term menu changes and additional strategies to enhance policy impact on consumer behavior and public health.

Backgroundparkrun, an international movement which organises free weekly 5km running events, has been widely praised for encouraging inactive individuals to participate in physical activity. Recently, parkrun received funding to establish 200 new events across England, specifically targeted at deprived communities. This study aims to investigate the relationships between geographic access, deprivation, and participation in parkrun, and to inform the planned expansion by proposing future event locations. MethodsWe conducted an ecological spatial analysis, using data on 455 parkrun events, 2,842 public green spaces, and 32,844 English census areas. Poisson regression was applied to investigate the relationships between the distances to events, deprivation, and parkrun participation rates. Model estimates were incorporated into a location-allocation analysis, to identify locations for future events that maximise deprivation-weighted parkrun participation. ResultsThe distance to the nearest event (in km) and the Index of Multiple Deprivation (score) were both independently negatively associated with local parkrun participation rates. Rate ratios were 0.921 (95%CI = 0.921-0.922) and 0.959 (0.959-0.959), respectively. The recommended 200 new event locations were estimated to increase weekly runs by 6.9% (from 82,824 to 88,506). Of the additional runs, 4.1% (n=231) were expected to come from the 10% most deprived communities. ConclusionParticipation in parkrun is wide spread across England. We provide recommendations for new parkrun event location, in order to increase participation from deprived communities. However, the creation of new events alone is unlikely to be an effective strategy. Further research is needed to study how barriers to participation can be reduced. Online Map, data, and source codeAn interactive online map is available here, and the annotated R source code and all data that were used to generate the results of this study are provided on a repository.

IntroductionPhysical activity is an important global health issue, yet surveillance and measurement methods vary considerably across countries and programs. This paper examines the use of the single-item physical activity (SIPA) measure through a comparative analysis of three representative national surveys and evaluates how well the SIPA reflects national estimates of meeting cutpoints for physical activity guidelines. Finally, we assess the application of the SIPA in the evaluation of four large community-based physical activity programs. MethodsWe describe the SIPA distribution using national data from the Active New Zealand Survey, the Australian National Health Survey and the Irish Sport Monitor. We explore the relationship between the SIPA and existing physical activity measures of guideline attainment using Receiver Operating Characteristic (ROC) analysis, with Area Under the Curve (AUC) as the measure of fit. For the four community programs, we compare pre- to post-program changes, including effect sizes (Cohens {delta}). ResultsAcross the three national datasets, mean SIPA values ranged from 2.68 to 3.31 days/week, with a bimodal distribution--people reported either zero or seven days of physical activity/week. A cutpoint at a threshold of [&ge;]3 days/week provided optimal classification of guideline attainment (AUC >0.8 in all countries). Across the four large community programs, SIPA values increased by a typical 0.5-1.0 days/week, with 10-30% more participants meeting physical activity guidelines post-program. ConclusionSIPA offers a feasible, low-cost option for both population surveillance and community program evaluation. This is particularly relevant in low-income countries and settings, and complements growing interest in device-based measurement (e.g., accelerometry). Testing of SIPA in low- and middle-income countries is urgently needed. Despite the need for future research, SIPA holds immediate promise as a standardised physical activity measure for policymakers, researchers and community program evaluators. Key MessagesThere are many measures used for physical activity population surveillance and for large program evaluation, but the single item physical activity (SIPA) offers new potential for coordination and standardisation of measures used by asking adults about the number of days/week they were active. Limited research has described population use of the SIPA. This study describes population physical activity levels in national surveys in Australia, New Zealand and Ireland, and also describes the use of the SIPA in the evaluation of physical activity change in four large community physical activity programs. The SIPA provides a validated, comparable, and easy to administer measure for use in physical activity surveillance systems and for policymakers and practitioners evaluating community programs.

Importance: While increased physical activity (PA) and decreased sedentary behavior (SB) are associated with favorable health outcomes, evidence regarding their causal effects on healthcare costs remains limited. Objective: To assess the causal effects of PA and SB on healthcare costs. Design: A two-sample Mendelian randomization (MR) study. Setting: Separate, non-overlapping cohorts with genetic instruments for self-reported and device-based PA and SB, and healthcare costs. Participants: The instruments used to assess self-reported PA were derived from a genome-wide meta-analysis of 606,820 individuals across 51 cohorts. Two large genome-wide association studies (GWASs) were used for self-reported SB (leisure screen time N=526,725; television watching N=408,815), while accelerometer-based GWASs (N=89,683-91,105) were used for device-based PA and SB. The instruments used to assess the outcome data were obtained from the FinnGen cohort (N=373,160). Exposures: Genetically predicted PA and SB. Main Outcomes and Measures: Validated genetic instruments for log-transformed annual healthcare costs derived from registers, including primary care, secondary care, and medication costs. Inverse variance weighting was used as the primary MR measure, while the sensitivity analyses included MR-Egger, weighted median, simple mode, weighted mode, F-score, Cochran's Q, and leave-one-out analysis. Results: Higher genetically predicted self-reported PA was associated with lower healthcare costs (causal estimate, {beta} = -0.166; 95% CI, -0.270 to -0.062). In contrast, higher genetically predicted SB (leisure screen time or television watching) was associated with higher healthcare costs across self-reported datasets ({beta} = 0.097; 95% CI, 0.064 to 0.130; {beta} = 0.114; 95% CI, 0.063 to 0.165, respectively). No associations were observed for device-based PA ({beta} = -0.014; 95% CI, -0.040 to 0.014) or SB ({beta} = -0.009; 95% CI, -0.197 to 0.179). Conclusions and Relevance: Findings based on genetically predicted PA and SB support a causal association between these behaviors and healthcare costs, suggesting that increasing population's leisure-time PA and reducing SB may decrease healthcare expenditure. This highlights the importance of promoting PA for both population health and long-term sustainability of healthcare systems. However, causal evidence remains partly limited, particularly for device-based measures of these behaviors.

Introduction High consumption of ultra-processed foods (UPF) is associated with adverse health outcomes and weight gain. Despite increasing calls for behavioural strategies to reduce UPF intake, no theory-informed intervention targeting UPF reduction has been evaluated in UK adults in alignment with national dietary guidance. We assessed the feasibility, acceptability, and preliminary behavioural and clinical outcomes of a multi-component intervention designed to reduce UPF consumption (and increase physical activity (PA)/minimally processed food (MPF) intake). Methods In this exploratory single-arm pre-post study, adults (N=45) living with overweight or obesity and habitual UPF intake [&ge;]50% of total energy were offered a 6-month behavioural intervention following a controlled feeding phase (UPDATE trial, stage 1). The intervention was developed using the Behaviour Change Wheel and Capability, Opportunity, Motivation-Behaviour (COM-B) model and included one-to-one sessions with a behavioural scientist, tailored print and digital materials, peer-support meetings, and a moderated group chat. Feasibility outcomes included uptake, retention, and intervention fidelity. Secondary outcomes included COM-B constructs, dietary intake, PA, clinical and self-reported outcomes, and qualitative feedback. Results Uptake was 91% (41/45). Retention at 6 months was 68% (28/41), with 83% (34/41) providing follow-up data (intention-to-treat). Median attendance at one-to-one sessions was 86% (interquartile range (IQR): 57-100) with 56% (23/41) attending all sessions (per-protocol). Fidelity to core behaviour change techniques was high. At 6 months, COM-B scores improved for healthy eating (+7%, standard deviation (SD): 8; p<0.001) and physical activity (+5%, SD: 9; p=0.013). UPF intake decreased by 25% of total energy (95% confidence interval (95%CI): -32, -17), with a corresponding increase in minimally processed foods (+23%; 95%CI: 17, 29). Vigorous physical activity increased (+60 min/week, IQR: 0-180), weekday sitting time decreased (-61 min/day, SD: 110), and weight reduced by 3.8 kg (IQR: -8.5-1.0; p=0.001). Findings were similar in per-protocol analyses. Qualitative data indicated perceived improvements in wellbeing and habit formation. Conclusion This theory-informed intervention demonstrated good feasibility and acceptability and was associated with improvements in targeted behavioural mechanisms and health-related outcomes. A randomised controlled pilot trial is warranted to evaluate effectiveness and refine implementation.