Background: Living in walkable neighborhoods may provide long-term cardio-metabolic health benefits to residents. Little empirical research has examined the behavioral mechanisms in this relationship. In this longitudinal study, we examined the potential mediating role of physical activity (baseline and 12-year change) in the relationships of neighborhood walkability with 12-year changes in cardio-metabolic risk markers. Methods: The Australian Diabetes, Obesity and Lifestyle study collected data from adults, initially aged 25+ years, in 1999–2000, 2004–05, and 2011–12. We used 12-year follow-up data from 2023 participants who did not change their address during the study period. Outcomes were 12-year changes in waist circumference, weight, systolic and diastolic blood pressure, fasting and 2-h postload plasma glucose, high-density lipoprotein cholesterol, and triglycerides. A walkability index was calculated, using dwelling density, intersection density, and destination density, within 1 km street-network buffers around participants’ homes. Spatial data for calculating these measures were sourced around the second follow-up period. Physical activity was assessed by self-reported time spent in moderate-to-vigorous physical activity (including walking). Multilevel models, adjusting for potential confounders, were used to examine the total and indirect relationships. The joint-significance test was used to assess mediation. Results: There was evidence for relationships of higher walkability with smaller increases in weight (P = 0.020), systolic blood pressure (P < 0.001), and high-density lipoprotein cholesterol (P = 0.002); and, for relationships of higher walkability with higher baseline physical activity (P = 0.020), which, in turn, related to smaller increases in waist circumference (P = 0.006), weight (P = 0.020), and a greater increase in high-density lipoprotein cholesterol (P = 0.005). There was no evidence for a relationship of a higher walkability with a change in physical activity during the study period (P = 0.590). Conclusions: Our mediation analysis has shown that the protective effects of walkable neighborhoods against obesity risk may be in part attributable to higher baseline physical activity levels. However, there was no evidence of mediation by increases in physical activity during the study period. Further research is needed to understand other behavioral pathways between walkability and cardio-metabolic health, and to investigate any effects of changes in walkability.

Disadvantaged areas experience higher levels of loneliness than advantaged areas, though studies rarely identify environmental determinants of neighbourhood inequity in loneliness. We studied the contribution of the quantity and quality of green space to neighbourhood inequity in loneliness in three buffer sizes (400 m, 800 m, 1600 m), using cross-sectional data from 3778 individuals aged 48–77 years old living in 200 neighbourhoods in Brisbane, Australia. Levels of loneliness were significantly higher in disadvantaged neighbourhoods, and these neighbourhoods had less green space and less access to quality green space. However, there was no evidence that neighbourhood disparities in green space contributed to the association between neighbourhood disadvantage and loneliness. Possible methodological and substantive reasons for this result are discussed.

Comprehensive apartment design policies have been legislated by Australian state governments to address concerns about poor design in residential buildings. These policies aim to improve apartment design and promote good health. This study examined whether: (1) residents living in apartments that implemented more minimum design requirements perceived better apartment design and amenity; and (2) increased implementation of minimum requirements and better perceptions of design were associated with positive mental wellbeing. Apartment complexes (n = 114, built 2006–2016) were sampled from Sydney, Perth, and Melbourne. Building plans and elevations were used to measure and score apartments for their implementation of 96 quantifiable policy-specific requirements and residents (n = 1072) completed a self-report survey on their apartment design and health. Multi-level linear regression models were used to account for clustered data. Residents in apartments with greater implementation of requirements for solar and daylight, indoor space, private open space, communal space and parking had more positive perceptions of their apartment in terms of natural light and winter thermal comfort, indoor space and layout, private open space, communal area quality, and parking, respectively (all p < 0.05). Perceptions of natural ventilation, summer thermal comfort, indoor space, and communal area quality were independently associated with positive mental wellbeing (all p < 0.05), but the objective implementation scores had no direct association. When implemented as intended, minimum requirements had a positive impact on perceptions of design, which were associated with mental wellbeing. The study underscores the importance of planning instruments and design review processes that increase industry uptake of minimum policy standards.

Background: Socioeconomic disadvantage is associated with mental illness, yet its relationship with mental well-being is unclear. Mental well-being is defined as feeling good and functioning well. Benefits of mental well-being include reduced mortality, improved immune functioning and pain tolerance, and increased physical function, pro-social behaviour, and academic and job performance. This study aimed to explore the relationship between individual socioeconomic position (SEP), neighbourhood disadvantage and mental well-being in mid-age adults. Methods: Multilevel modelling was used to analyse data collected from 7866 participants from the second (2009) wave of HABITAT (How Areas in Brisbane Influence healTh and activiTy), a longitudinal study (2007–2016) of adults aged 40–65 years living in Brisbane, Australia. Mental well-being was measured using the Warwick Edinburgh Mental Well-Being Scale (WEMWBS). Exposure measures were education, occupation, household income, and neighbourhood socioeconomic disadvantage. Results: The lowest MWB scores were observed for the least educated (β = − 1.22, 95%CI = − 1.74, − 0.71), those permanently unable to work (β = − 5.50, 95%CI = − 6.90, − 4.10), the unemployed (β = − 2.62, 95%CI = − 4.12, − 1.13), and members of low-income households (β = − 3.77, 95%CI = − 4.59, − 2.94). Residents of the most disadvantaged neighbourhoods had lower MWB scores than those living in the least disadvantaged neighbourhoods, after adjustment for individual-level SEP (β = − 0.96, 95%CI = − 1.66, − 0.28). Conclusions: Both individual-level SEP and neighbourhood disadvantage are associated with mental well-being although the association is stronger for individual-level SEP. This research highlights the need to address individual and neighbourhood-level socioeconomic determinants of mental well-being.