Abstract
BACKGROUND: Extremes of body mass index (BMI) and low Muscle Mass are associated with increased morbidity and mortality in older adults. Modifiable factors may include the frequency of participation in key out-of-home activities. METHODS: Using a cross-sectional study design, we examined the relationship between frequencies of out-of-home activities-specifically dining, grocery shopping, exercise, and recreation-and BMI as well as Muscle Mass among community-dwelling adults aged 50 years and older in Singapore (n = 1,118). Frequencies of out-of-home activities over 14 days were measured using Global Positioning System (GPS)-based travel data. Participants' sociodemographic, health, and neighborhood environmental information was collected through a questionnaire, physical performance tests, and publicly available databases. Multivariable regression was performed to examine the association between activity frequency and BMI as well as Muscle Mass while controlling for known predictors of the outcome variables. RESULTS: We found a positive and significant association between out-of-home dining frequency and BMI even after controlling for exercise frequency and self-reported physical activity level. Out-of-home exercise and recreation frequencies were also associated with Muscle Mass. Importantly, increased participation in out-of-home recreational activities was significantly associated with higher Muscle Mass, independent of out-of-home exercise frequency and self-reported physical activity level. Other findings included association between low gait speed and higher BMI. Lower perceived income adequacy was also associated with higher BMI, after controlling for income surrogates such as housing type, education, and employment status. Living in a neighborhood with hills and/or barriers to walking from place to place was associated with greater Muscle Mass. However, most environmental factors including distance to nearest dining cluster and supermarket were not associated with BMI or Muscle Mass. CONCLUSIONS: Key modifiable life activities associated with clinically significant differences for BMI include out-of-home dining frequency, whereas for Muscle Mass, they include out-of-home recreation and exercise frequencies. TRIAL REGISTRATION: Not applicable.