Calibration of activity-related energy expenditure in the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)

Objectives: Usual physical activity (PA) is a complex exposure and typical instruments to measure aspects of PA are subject to measurement error, from systematic biases and biological variability. This error can lead to biased estimates of associations between PA and health outcomes. We developed a calibrated physical activity measure that adjusts for measurement error in both self-reported and accelerometry measures of PA in adults from the US Hispanic Community Health Study/Study of Latinos (HCHS/SOL), a community-based cohort study. Design: Total energy expenditure (TEE) from doubly labeled water and resting energy expenditure (REE) from indirect calorimetry were measured in 445 men and women aged 18–74 years in 2010–2012, as part of the HCHS/SOL Study of Latinos: Nutrition & Physical Activity Assessment Study (SOLNAS). Measurements were repeated in a subset (N = 98) 6 months later. Method: Calibration equations for usual activity-related energy expenditure (AEE = 0.90 × TEE-REE) were developed by regressing this objective biomarker on self-reported PA and sedentary behavior, Actical accelerometer PA, and other subject characteristics. Results: Age, weight and height explained a significant amount of variation in AEE. Actical PA and wear-time were important predictors of AEE; whereas, self-reported PA was not independently associated with AEE. The final calibration equation explained fifty percent of variation in AEE. Conclusions: The developed calibration equations can be used to obtain error-corrected associations between PA and health outcomes in HCHS/SOL. Our study represents a unique opportunity to understand the measurement characteristics of PA instruments in an under-studied Hispanic/Latino cohort

Disordered eating behaviours and cognitions in young women with obesity: relationship with psychological status

Objective: To examine levels of eating disorder behaviours and cognitions of young women with obesity in the Australian Capital Territory, Australia and assess the impact upon psychological status.\ud \ud \ud Design: General population cross-sectional survey.\ud \ud Subjects: A total of 4891 young women from the community aged 18–42 years, of which 630 were in the obese weight range.\ud \ud Measurements: Body mass index (BMI), eating disorder psychopathology (eating disorder examination questionnaire), and psychological distress (K-10).\ud \ud Results: Women with obesity had significantly higher levels of dietary restraint, eating concern, weight concern, shape concern, binge eating, misuse of diuretics, use of diet pills and fasting compared to other women in the community. These eating disorder cognitions and behaviours were associated with increased levels of psychological distress. In women with obesity, eating concern, weight concern, shape concern, dietary restraint and decreased age predicted psychological distress in a multivariate model. Among other women in the community, behaviours such as laxative misuse, 'hard' exercise and subjective bulimic episodes also contributed to the model predicting psychological distress.\ud \ud Conclusion: As disordered eating psychopathology is high in young obese women and negatively impacts upon psychological status, obesity prevention and treatment should consider eating disorder psychopathology and mental health outcomes