International Journal of Behavioral Nutrition and Physical Activity

Abstract Background: Previous physical activity simulation studies only account for the effects of cardiovascular diseases, diabetes, dementia, and some cancers, which neglects many of its costs and benefits. We estimate the health and economic impacts of increased physical activity in Australia, including those on mental health, increased injury rate, and conditions mediated by other risk factors, commencing 2021, over 20 years. Methods: We used a Proportional Multistate Lifetable Model specified with disease rate and risk factor forecasts, and causal associations, derived from the Global Burden of Disease study and other sources. Findings: If all Australians shifted to the maximum physical activity level of 4200+ MET-min/week, there would be: 653,000 (230,000 - 1,210,000) or 0.16% more HALYs lived; 9,720 (7,400 to 12,700) or 1.33% fewer deaths before age 75; increased working age income of AUD$16.8 billion ($12.8 - $22.2 billion); and decreased health expenditure of $748 million (-$4.46 billion - $6.98 billion) or 0.02%. Net health gains diminish for each additional 600 MET-min/week increase in physical activity, and above 4,200 MET-min/week the health costs from injuries outweigh the reduction in health costs from avoided disease. Because of injuries, increasing physical activity in the lowest activity group to meet the physical activity guidelines reduces health expenditure more ($1.86 billion; 896 million - 3.13 billion) than shifting to maximum activity levels. Interpretation: Increasing physical activity levels in Australia would improve population health (even allowing for injuries due to participation), reduce health spending, and increase income. Funding: Australian Sports Commission. TB is funded by NHMRC Investigator Grant (2023) #2026992

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.

Background: This prospective cohort analysis investigated how age, sex, and body morphology modify associations of physical activity (PA) intensity, duration, and volume with cardiovascular disease (CVD) mortality. Methods: We analysed wrist-worn accelerometer data from 8,661 adults (51.9% women) in the National Health and Nutrition Examination Survey. The outcome was CVD mortality. PA intensity and volume were quantified using the intensity gradient and average acceleration, respectively. Survey-weighted Cox proportional hazards models were used to estimate associations, including interaction terms with age, sex, or body morphology (waist-to-height ratio as indicator of adiposity). Results: Median (interquartile range) follow-up was 81 (69, 94) months. All hazard ratios (HR) compare 50th with 25th percentile. Beneficial associations between CVD mortality and PA were stronger in younger than older adults for intensity (e.g., 45-year-olds: HR=0.47, 95%CI:0.29-0.75 vs 75-year-olds: HR=0.75, 95%CI:0.54-1.06), and volume (e.g., HR=0.18, 95%CI:0.07-0.71 vs 0.29, 95%CI:0.16-0.51). In women, intensity-related association were stronger than in men (HR=0.45, 95%CI:0.31-0.65 vs HR=0.79, 95%CI:0.50-1.24). Volume-related associations were stronger in men (HR=0.37, 95%CI:0.22-0.60 vs HR=0.24, 95%CI:0.11-0.51), though with earlier plateauing and greater uncertainty. Associations were observed across waist-to-height ratio levels but attenuated at higher values (intensity: waist-to-height ratio 0.5, HR=0.45, 95%CI:0.29-0.69 vs 0.6, HR=0.69, 95%CI:0.49-0.97; volume: 0.5, HR=0.07, 95%CI:0.03-0.17 vs 0.6, HR=0.28, 95%CI:0.17-0.45). Conclusion: Older adults and men may benefit more from increasing PA volume than intensity, whereas younger adults and women may benefit more from higher-intensity PA. Although benefits were observed across adiposity levels, associations were attenuated as adiposity increased, suggesting stronger benefits in individuals with low-to-moderate adiposity.

Background Higher levels of sedentary behaviour, such as leisure screen time (LST), and lower levels of physical activity are associated with diseases across multiple body systems which contribute to a large global health burden. Whether these associations are causal is unclear. The primary aim of this study is to investigate the causal effects of higher LST (given greater power) and, secondarily, lower moderate-to-vigorous intensity physical activity (MVPA), on a wide range of diseases in a hypothesis-free approach. Methods A two-sample Mendelian randomisation phenome-wide association study was conducted for the main analyses. Genetic single nucleotide polymorphisms (SNPs) were first selected as exposure genetic instruments for LST (hours of television watched per day; 117 SNPs) and MVPA (higher vs. lower; 18 SNPs) based on the genome-wide significant threshold (p < 5*10-8) from the largest relevant genome-wide association study (GWAS). For disease outcomes, we used summary results from FinnGen GWAS, including 1,719 diseases defined by hospital discharge International Classification of Diseases (ICD) codes in 453,733 European participants. For the main analyses, we used the inverse-variance weighting method with a Bonferroni corrected p-value of p [&le;] 3.47*10-4. Sensitivity analyses included Steiger filtering, MR-Egger and weighted median analyses, and data from UK Biobank were used to explore replication. Findings Genetically predicted higher LST was associated with increased risk of 87 (5.1% of the 1,719) diseases. Most of these diseases were in musculoskeletal and connective tissue (n=37), genitourinary (n=12) and respiratory (n=8) systems. Genetic liability to lower MVPA was associated with six diseases: three in musculoskeletal and connective tissue and genitourinary systems (with greater risk of these diseases also identified with higher LST), and three in respiratory and genitourinary systems. Sensitivity analyses largely supported the main analyses. Results replicated in UK Biobank, where data available. Conclusions Higher levels of sedentary behaviour, and lower levels of physical activity, causally increase the risk of diseases across multiple body systems, making them promising targets for reducing multimorbidity.

BackgroundEvidence on the long-term impact of urban green and blue spaces (UGBS) interventions remains limited. This study is a 15-year evaluation of an urban greenway development in Belfast (United Kingdom), assessing the potential effects of this UGBS intervention on physical activity (PA), mental wellbeing and co-benefits. MethodsUsing quasi-experimental design, a repeated cross-sectional survey was conducted in 2010 (baseline), 2017 (post-opening) and 2023 (long-term follow-up) with about 1,200 adults participated each wave. Outcomes included PA, mental wellbeing, general health, quality of life, social capital and environmental perception. Multilevel mixed-effect regressions were performed to examine within-group changes at long-term follow-up. Difference-in-differences analysis investigated the between-group changes that might be attributed to the greenway. Additional comparative analyses included distance-decay analysis and comparison with population trends in Northern Ireland. ResultsAt six years after completion, the greenway intervention appears to buffer a decline in duration of PA - mainly from moderate-intensity activity (decline lower by 118.6 min/week, 95%CI: 3.9-232.2) but with no significant impact on the proportion of the population meeting the recommended PA level. The intervention is associated with a smaller decline in self-rated health (4.98 units; 95%CI: 0.62-9.34) relative to control group. Intervention association with mental wellbeing was positive but not significant (p=0.30). The greenway also showed positive effects on social capital and environmental perceptions, with impacts most evident in improving safety and trust in the local area. ConclusionThis study provides evidence to support the public health impact of UGBS and its long-term health and social benefits.

Objective: To investigate in the National School Feeding Program (PNAE) the local level drivers and barriers to the implementation of four guidelines: the banning of sugary drinks; restrictions on the procurement of processed and ultra-processed foods; the mandatory increase in weekly servings of fruits and vegetables offered to students; and mandatory direct procurement from family farmers. Design: Qualitative study that used semi-structured interviews. Street level bureaucracy theory informed the theoretical framework and thematic analysis. Setting: Brazilian municipalities, across the country five geographic regions (North, Northeast, Southeast, South, and Midwest). Participants: Stakeholders (e.g. nutritionists, school cooks, and food procurement managers) involved in the local implementation of the PNAE program across the country. Results: Ninety stakeholders were interviewed. Stakeholders reported having autonomy to perform their activities, collaboration and support from other members within the local government and food providers, adequate infrastructure such as a well-equipped kitchens, the availability of trained personnel, and political commitment as drivers for optimum program implementation. Reported barriers included lack of support and resistance to change among cooks, teachers and parents; insufficient physical and human resources; and limited political commitment. When barriers outweighed drivers, interviewees reported adapting their practices, often in restrictive ways that could compromise the implementation of the program. Conclusions: Drivers and barriers to local PNAE implementation were generally similar across studied municipalities, although their magnitude varied. In contexts of greater economic vulnerability and fiscal constraint, additional support and targeted actions from the federal government may be required to strengthen local implementation

Abstract Background: Insufficient physical activity, excessive sedentary time, and suboptimal sleep are linked to premature mortality and chronic disease and may contribute to social inequalities in health, but most evidence is self-reported. Device-measured, nationally representative data capturing the full 24-hour movement spectrum remain scarce, particularly among older adults. This study examined social, economic, and environmental disparities in 24-hour movement behaviours in the 2021-23 English Longitudinal Study of Ageing (ELSA) accelerometry sub-study. Methods: A subset of 5,382 ELSA participants (71.9%) was invited to wear an Axivity AX3 wrist accelerometer for eight days, with 4,354 (80.9%) agreeing. Raw data were processed using machine learning to derive step count, sleep duration, moderate-to-vigorous and light physical activity, sedentary time, and time in bed. Cross-sectional associations with sex, age, education, marital status, wealth, and urbanicity were examined using linear regression. Findings: Data from 3,648 participants (mean age 68.5 {+/-} 9.3 years; 44.3% men) were included in wear time analyses (median 6.6 days, IQR 6.0-6.9), with 3,161 (86.7%) having sufficient wear time for movement behaviour analyses. Older, unmarried, or lower education/wealth participants were less active, more sedentary, and slept less. Rural participants were more active than urban participants. Women accumulated fewer steps and less moderate-to-vigorous physical activity and sedentary time, but more light activity and longer sleep than men. Interpretation: Social, economic, and environmental disparities exist across the full 24-hour movement spectrum, highlighting population groups for targeted interventions. Follow-up data will clarify how 24-hour movement behaviours influence healthy ageing and contribute to social inequalities in health.

HighlightsO_LIHealth inequalities have widened over 15 years, favouring high-income groups C_LIO_LIInequality in physical activity & mental health widened the most pre-intervention C_LIO_LIPost-intervention, inequalities persisted but stayed relatively unchanged. C_LIO_LILong-term illness and unemployment were key drivers of inequality C_LIO_LIThe greenway may have slowed down the inequality widening but the impact is limited C_LI BackgroundEvidence concerning health inequalities following urban green and blue space UGBS) interventions is limited. This study examined the changes in health inequalities after a major urban regeneration project, the Connswater Community Greenway (CCG), in Belfast, UK. MethodCross-sectional household surveys were conducted in 2010/11 (baseline), 2017/18 (immediately after completion), and 2023/24 (long-term follow-up) with a sample of approximately 1,000 adults each wave. Using concentration indices (CI), income-related health inequalities for three outcomes (physical activity, mental wellbeing and quality of life) were measured. A regression-based decomposition of concentration index examined the contribution of sociodemographic factors to the observed inequalities underpinning each outcome over time. ResultsAcross three waves, there was widening of inequalities over the 15-year period across all three health outcomes, with those from high-income groups reported higher levels of physical activity (CI=0.33, SE=0.026), better mental wellbeing (CI=0.03, SE=0.003), and better quality of life (CI=0.09, SE=0.008). The widening inequalities mainly occurred during the construction phase of CCG (2010-2017) and remained stable post-intervention (2017-2023). Decomposition analysis revealed that the pro-poor concentration of long-term illness and unemployment was the key driver that together explained approximately 51%-76% of the inequalities. ConclusionThe CCG was limited in reducing health inequalities which were mainly driven by long-term illness and unemployment - factors beyond the direct scope of the UGBS intervention - resulting in low-income groups likely to fall further behind the wealthier groups. The widening of inequality is consistent with findings from other public interventions that did not have a primary equity focus.

Background Physical activity (PA) and body mass index (BMI) shape cardiovascular risk, particularly in women. Yet, little research exists examining intersectional social axes shaping PA and BMI inequities among women living in the United States (US). Methods Data included women sampled in the 2015-2020 National Health and Nutrition Examination Survey. We used Intersectional Multilevel Analysis of Individual Heterogeneity and Discriminatory Accuracy (I-MAIHDA) via linear models to examine PA (n=,4591) and BMI (n=4,596) inequities across intersectional strata defined by race/ethnicity, age, education, nativity, and work status. We further quantified the contribution of these strata to the observed inequities and estimated additive fixed effects. Results In the null model, intersectional strata explained 4.6% and 13.8% of the variance in PA and BMI inequities, respectively, with 99.2% for PA and 97.5% for BMI explained by age, race/ethnicity, education, nativity, and occupation status. On average, Asian and Black women, those aged 35-49 years, those born outside the US, and those with less than a high school diploma had the lowest predicted mean PA. For BMI, Black and Hispanic/Latino women and those younger than 64 years had the highest mean BMI. Conclusion PA and BMI inequities are mostly explained by race/ethnicity, age, education, nativity, and work status. Our findings offer insights into universal and potential policy-informed health promotion strategies that may be tailored to women with these social identities and lived experiences that have shaped physical activity and body mass index inequities.

Background: Hospital canteens provide an effective setting for improving the dietary habits of users. The study evaluates the food choices of users after an educational and environmental intervention, considering nutritional composition and environmental impact, and to compare the results with pre-intervention choices. Methods: A cross-sectional study was conducted in three hospital canteens (C1, C2, C3) in northeastern Italy, during two index weeks in September 2022 (T0) and 2023 (T1). An intervention was introduced between T0 and T1, consisting of posters on healthy eating, descriptive norm messages, and environmental changes regarding fruit and vegetables. Photos of lunch trays were collected, and choices were analyzed for nutritional composition and sustainability. Results: 2,851 trays were analyzed: 1,227 at T0 (798 in C1, 228 in C2 and 201 in C3) and 1,624 at T1 (1,005 in C1, 348 in C2, 271 in C3). In C1 and C3, there was an increase in median energy (+30 kcal; +135 kcal) compared to pre-intervention meals, while in C2 there was a decrease (-118 kcal). Despite a slight improvement in macronutrient composition, at T1 meals in all canteens were still high in lipids (30%E; 39%E; 35%E) and low in carbohydrates (44%E; 39%E; 41%E). The fibre value fell within the recommended range only in C1 and C3. The median carbon (CF) and water (WF) footprints of meals in all canteens remained high: at T1 CF ranged from 966 gCO2eq. to 1,227 gCO2eq. and WF from 1,025 L H2O to 1,207 L H2O. Conclusion: The intervention has led to partial improvements in food choices. To achieve more significant results, it may be necessary to implement a parallel intervention on food offer.

IntroductionIncreasing global prevalence of overweight and obesity underscores the need for context-specific evidence to guide preventive policy implementation. Previous modelling showed that promoting healthy indigenous foods, implementing a 20% tax on sugar-sweetened beverages (SSBs), and introducing mandatory kilojoule menu labelling in formal-sector restaurants in Kenya were health-promoting, cost-saving, and cost-effective. Cost-effectiveness evidence is strengthened when considered alongside broader policy implementation considerations. We engaged stakeholders to assess additional implementation considerations relevant to decision-makers and to evaluate the stakeholder engagement process used in the modelling study. MethodsUsing the Assessing Cost-Effectiveness approach, we conducted a stakeholder-engaged study with national-level Kenya stakeholders recruited through purposive and snowball sampling. Through deliberative dialogue at a hybrid workshop, stakeholders assessed implementation considerations such as equity, feasibility and sustainability using a colour-coded scoring tool. We evaluated the engagement process using an anonymous survey covering seven stakeholder-engaged research domains. We analysed responses thematically. ResultsAcross the three interventions, most implementation considerations for feasibility, reach and impact, affordability, acceptability, and sustainability were assessed as medium or high. Industry acceptability of kilojoule labelling and SSB tax and affordability of kilojoule labelling to industry were rated low. Equity scores varied. Stakeholders proposed complementary measures that could raise low ratings to favorable scores. Clarity on stakeholder roles was identified as a key strength of the engagement process, while competing time commitments limited participation. ConclusionStakeholder insights contextualise prior cost-effectiveness evidence within policy-relevant implementation considerations and inform current fiscal and regulatory debates. Evaluation of the stakeholder engagement process underscores its contribution to strengthening public health research.

Introduction: Physical inactivity and sedentary behaviour are significant risk factors for noncommunicable diseases. Engaging in regular physical activity (PA) during childhood is crucial for preventing long-term health burdens. This study examined PA levels and associated factors among upper primary school children in Lusaka, Zambia. Methodology: A cross-sectional survey was conducted from August to October 2022 among 638 children aged 9-18 years from six public and six private schools. Data were collected using the Physical Activity Questionnaire for Children (PAQ-C), Youth Risk Behaviour Survey (YRBS), Model of Youth Physical Activity Questionnaire (MYPA), and 3-Day Physical Activity Recall Questionnaire (3DPAR). Analyses included descriptive statistics, Chi-square, Fishers exact tests and multivariable binary logistic regression at a 0.05 significance level and 95% confidence interval. Results: Most participants (82%) were insufficiently active, with only 18% achieving sufficient PA. Reported barriers included lack of playgrounds or parks near home (p=0.012), neighbourhood safety concerns (p=0.041), and limited parental supervision (p=0.006). Watching television reduced the odds of PA by 69% (aOR=0.31; 95% CI: 0.13-0.75). Conversely, peer support increased activity by 15% (aOR=1.15, 95% CI: 0.67-1.97), while not being concerned about showering or fixing hair after PA increased activity by 94% (aOR=1.94; 95% CI: 1.21-3.11). Conclusion: The majority of school children in this study did not meet recommended PA levels. Barriers to activity included personal, parental, and environmental factors. Interventions should prioritise safe play spaces, increased parental and peer support, and reduced screen time to curb future non-communicable disease risks.

Loneliness--the perceived discrepancy between desired and actual social connection--is a common and aversive psychological state associated with a range of adverse health outcomes. Several theoretical models suggest that these associations may operate partly through health behaviors. In this preregistered study, we used data from the All of Us Research Program to evaluate associations of loneliness and functional rurality (FR), a study-specific contextual index of reduced neighborhood accessibility, with Fitbit-derived physical activity and sleep outcomes. Final samples included 16,912 participants for physical activity analyses and 13,937 for sleep analyses. In adjusted models, higher FR was associated with greater loneliness ({beta} = 0.061, 95% CI [0.045, 0.077], p = 9.63 x 10-14). FR and loneliness were independently associated with fewer daily steps and lower moderate-to-vigorous physical activity. Loneliness was also associated with shorter sleep duration, greater sleep duration variability, higher odds of short sleep, and higher odds of low sleep efficiency. FR was not associated with sleep duration or sleep duration variability but showed a small positive association with mean sleep efficiency and lower odds of low sleep efficiency. Interaction analyses provided little evidence that FR modified the associations of loneliness with most outcomes, although the FR x loneliness interaction was significant for sleep duration variability, indicating that loneliness was more strongly associated with irregular sleep duration in higher-FR contexts. Sensitivity analyses using stricter valid-day thresholds, winsorization, quartile-based exposure coding, and a backward 30-day window yielded directionally similar findings. These results suggest that FR and loneliness are independently associated with lower physical activity, whereas loneliness shows a more consistent relationship with adverse sleep patterns.

Background: The timing of energy intake could be important in the development of obesity. However, most observational evidence stems from adults, anthropometric defined obesity outcomes, single meal timing phenotyping, and traditional regression modeling. Objective: We aimed to describe meal timing patterns in adolescents and determine if they associated with fat mass by modeling the median and all other percentiles of the frequency distribution. Methods: We analyzed data from the Sleep and Growth Study 2 (S-Grow2, N=286, 12-13y). Participants completed 3-day 24-hour dietary recalls and time stamped eating occasions were used to define 8 meal timing traits, with aide from self-reported wake and bed timing. Principal component analysis (PCA) identified multi-dimensional meal timing patterns. Fat mass index (FMI) was estimated using dual energy X-ray absorptiometry. Quantile regression assessed if there were associations between meal timing traits and FMI across the entire FMI frequency distribution. Results: The typical first and last eating occasions were 8:00am (40 minutes after waking) and 8:00pm (2.7 hours before sleep), respectively, thus the eating period typically lasted 11.5 hours per day. The typical eating period midpoint was 2:15pm, and the timing when 50% of energy intake was consumed typically occurred at 3:15pm. PCA revealed three meal timing patterns: 1) Delayed Start, Condensed Eating Period (43% of variance; shorter eating period and delayed timing of first eating); 2) Late, Sleep Proximal Eating (30% of variance; later timing of last eating and extended eating period), and 3) Later Energy Intake (10% of variance; delayed energy intake midpoint). Higher scores for the Delayed Start, Condensed Eating Period pattern associated with higher body mass index and FMI at the upper tails of their distributions. Conclusions: Distinct multidimensional meal timing patterns emerged in early adolescence, with the delayed start, condensed eating period pattern potentially associated with higher adiposity.

Objective: To investigate the effects of breaking up prolonged sedentary behavior (SB) on daily movement behavior and energy balance in adults with overweight/obesity. Methods: Thirty participants (16F/14M; 34.2+-7.3y; 29.5+-3.2kg/m2) were randomized to either BREAK (nine hourly 5-min brisk walking bouts) or a duration-matched intervention, ONE (45-min brisk walking), both performed 5 days/week for 6 weeks. Pre- and post-intervention, daily SB and physical activity (PA; accelerometry), body composition (doubly labeled water [DLW]), total daily energy expenditure (TDEE; DLW), appetite, and fasting leptin were measured. Linear-mixed effects models tested time effects and time-by-group interactions. Results: Only BREAK reduced prolonged SB (-8%; interaction: p=0.043). Both groups shifted SB-PA composition toward greater moderate-to-vigorous PA with proportional reductions in SB and light PA (time: all p<0.012), which were associated with increases in TDEE (+0.67 MJ/d; time: p=0.040). Body and fat mass increased in ONE only (interaction: p=0.061 and p=0.055). No differences were noted in energy intake, appetite, or leptin levels. Conclusions: Spreading short PA bouts throughout the day increases MVPA and TDEE to the same extent as a traditional continuous PA bout. Future studies should investigate whether minor differences in body composition are driven by distinct behavioral/physiological compensations influenced by the daily pattern of PA/SB.

Background: Digital phenotyping using wearable devices and ecological momentary assessment (EMA) enables continuous, real-world monitoring of physiological and emotional states, but identifying high-risk stress states in real time remains challenging. We examined day-level associations between emotional distress and heart rate variability (HRV), and assessed whether daily physical activity modifies this relationship using longitudinal wearable and EMA data. Methods: The Smart Momentary Interactive Longitudinal Evaluation Study (SMILES) was a prospective cohort study conducted among STEM graduate students in the U.S. in 2025. Participants wore an Oura Ring Generation 3 continuously for five months and completed daily EMA surveys assessing emotional distress. The primary outcome was nightly HRV measured as the root mean square of successive differences and log-transformed for analysis. Quantile regression within a quadratic inference function framework was used to estimate associations at the 25th, 50th, and 75th percentiles of HRV, accounting for within-participant correlation and time-varying covariates. Findings: Thirty-one participants contributed 1,724 person-days of observation. High emotional distress was associated with lower HRV across the HRV distribution, with the strongest association observed at the lower HRV quantile ({beta} = -0.094, 95\% CI: [-0.111, -0.078]). A significant interaction between daily step count and emotional distress was observed across quantiles, such that higher physical activity was associated with higher HRV on high emotional distress days but not on low-to-moderate distress days. Interpretation: Integration of wearable-derived physiological data with EMA enables real-time identification of high-risk stress states in naturalistic settings. The observed buffering effect of physical activity during periods of elevated emotional distress suggests that wearable-guided, personalized just-in-time adaptive interventions, such as physical activity prompts, could be deployed to improve autonomic regulation and mental health.

BackgroundCommercial motorcycle riders are among the most vulnerable road users in low- and middle-income countries and contribute substantially to the burden of road traffic injuries. The use of personal protective equipment (PPE), including helmets and protective clothing, reduces injury severity; however, uptake remains suboptimal. This study evaluated the effectiveness of a theory-driven health education intervention in improving knowledge, attitudes, and use of PPE among commercial motorcycle riders in Cameroon. MethodsA quasi-experimental, non-randomized controlled before-and-after study was conducted in Limbe (intervention) and Tiko (control) Health Districts between August 4, 2024, and April 6, 2025. Participants were recruited from a cohort of commercial motorcycle riders and followed over an eight-month intervention period. The intervention, guided by the Health Belief Model and developed using the Intervention Mapping framework, combined face-to-face sensitization sessions with mobile phone-based educational messaging adapted to participants literacy levels and communication preferences. Data were collected at baseline and endline using structured questionnaires and direct observation checklists. Intervention effects were estimated using difference-in-differences analysis with generalized estimating equations, adjusting for socio-demographic factors. ResultsA total of 313 riders were enrolled at baseline (183 intervention, 130 control), with 249 retained at endline (149 intervention, 100 control). The intervention was associated with significant improvements in PPE knowledge ({beta} = 2.91; 95% CI: 2.14-3.68; p < 0.001) and attitudes ({beta} = 5.76; 95% CI: 4.32-7.21; p < 0.001) compared with the control group. No statistically significant effect was observed for PPE practice scores ({beta} = 0.21; 95% CI: -0.09-0.52; p = 0.171). Among individual PPE items, helmet use increased significantly in the intervention group relative to the control group (AOR = 2.38; 95% CI: 1.19-9.45; p = 0.036), while no significant effects were observed for gloves, trousers, eyeglasses, or closed-toe shoes. ConclusionThe theory-driven health education intervention significantly improved knowledge and attitudes toward PPE and increased helmet use among commercial motorcycle riders but did not lead to broader improvements in the uptake of other protective equipment. These findings highlight the need for complementary structural and policy interventions to address persistent barriers to PPE use in similar low-resource settings. Trial registrationClinicalTrials.gov Identifier: NCT07087444 (registered July 28, 2025, retrospectively)

Background: Ethnic minorities and socioeconomically disadvantaged populations in the UK are at increased risk of obesity. We modelled longitudinal body mass index (BMI) trajectories through infancy, childhood, and adolescence to identify at-risk groups and modifiable risk factors. Methods: This cohort sampled 10,350 White and South Asian children born in Leicestershire, 1985-1997. We included 5,571 participants with [&ge;]3 BMI measurements between 0-18 years collected from healthcare records, questionnaires, and study visits. We used Group-Based Trajectory Modelling of BMI, separately by sex and ethnicity, and combined. We identified at-risk groups and modifiable risk factors using multinomial logistic regression, with inverse probability weighting to reduce selection bias. Results: We identified similar five BMI trajectories across sex and ethnicity: stable normal BMI (47%); persistent low BMI (30%); early overweight resolving (8%); childhood onset obesity (4%); and adolescent onset overweight (11%). Childhood onset obesity deviated from stable normal BMI at 2-4 years of age, adolescent onset overweight at 4-6 years. South Asians were at higher risk of childhood onset obesity (aOR: 1.66 [95%CI 1.08-2.53]) and adolescent onset overweight (1.29 [0.98-1.71]) than Whites. Children from deprived backgrounds (1.66 [0.92-2.82], most vs least deprived quintile) and those with less educated parents (1.67 [1.08-2.63], compulsory vs higher education) were at increased risk of childhood onset obesity. Smoking during pregnancy (1.50 [0.88-2.54]) and absence of breastfeeding (1.56 [1.07-2.29]) increased risk of childhood onset obesity. Physical activity decreased risk of childhood onset obesity (0.64 [0.44-0.93], [&ge;]4 vs 0-3 hours/week) and adolescent onset overweight (0.75 [0.59-0.94]). Conclusion: BMI trajectories diverge as early as age 2 years, revealing ethnic and social inequalities. Obesity strategies in the UK should intervene during critical windows in early life and prioritise South Asian children and those from socioeconomically deprived backgrounds.

Objectives. To test whether the association between household income and tooth retention differs by race/ethnicity and whether this interaction varies by reason for the most recent dental visit among US adults. Methods. We analyzed 13,190 adults in the National Health and Nutrition Examination Survey (2009 to 2018). Survey weighted linear regression estimated interactions between household income and race/ethnicity in models of tooth retention, stratified by reason for last dental visit. Results. Higher income was associated with greater tooth retention across groups, but income related gains were larger for Non-Hispanic White adults than for Non Hispanic Black and Mexican American adults, particularly in problem-focused care settings. In problem focused visits, each higher income category was associated with 0.5 additional teeth among White adults (95% CI 0.4, 0.6) versus 0.2 (95% CI 0.0, 0.4) among Black adults and 0.1 (95% CI 0.1, 0.3) among Mexican American adults. Racial differences were attenuated in routine check-up contexts. Conclusions. Income related gains in tooth retention differed by race/ethnicity and dental care context. Public Health Implications. Expanding access alone may be insufficient to reduce racial inequities in oral health.

Background: Accurate dietary assessment is essential for precision nutrition and effective nutrition surveillance. However, portion size estimation remains a persistent challenge, particularly in culturally diverse regions such as Central Asia. Traditional self-reporting tools often yield inconsistent results due to communal eating practices and unfamiliarity with standard measures. Objective: To address these limitations, this study aimed to compare three methods: unassisted human judgment, visual food atlas assistance, and an artificial intelligence (AI) model, using Central Asian food items. Methods: In this cross-sectional study, 128 participants from Astana, Kazakhstan, visually estimated portion sizes of 51 foods and 8 beverages from standardized photographs. Participants were randomized into two groups: one using unassisted visual estimation and the other aided by a regionally tailored digital food atlas. Additionally, an AI model trained on Central Asian food images was evaluated. Actual food weights served as the reference standard. Accuracy was assessed using Mean Absolute Error (MAE) and Mean Absolute Percentage Error (MAPE) across food types and portion sizes. Results: The atlas-assisted group demonstrated the highest accuracy, with the lowest MAE (80.81g) and MAPE (44.76%) across all portions. The AI model showed promising results for average portions (MAE: 79.07g, MAPE: 67.91%) but underperformed on small portions, particularly for meat-based items. Unassisted estimates were the least accurate (MAE: 133.86g, MAPE: 79.40%). Across food categories, visual aids consistently improved accuracy, while AI demonstrated variability by texture and portion size. Conclusions: Culturally adapted visual atlases significantly enhance portion size estimation accuracy in non-Western, communal-eating contexts. While AI models hold promise for dietary assessments, particularly with standard portions and beverages, further refinement is needed for complex food items and small portion types. These findings support the integration of visual and AI-based tools into region-specific dietary monitoring strategies.