Neighborhood Walkability Is Associated with Physical Activity and Prediabetes in a Behavioral Weight Loss Study: a Secondary Analysis.

BACKGROUND: Socio-environmental factors may affect uptake and utility of behavioral interventions targeting weight loss and cardiometabolic health. To evaluate the relation of neighborhood walkability to physical activity (PA) and glucose control in a sample of adults with overweight/obesity participating in a weight loss study. METHODS: Secondary analysis of a 12-month behavioral weight loss intervention (2011-2015) using one-group pretest-posttest design. Neighborhood walkability was assessed via residential Walk Score (0-100) at study entry. Fasting plasma glucose (FPG) via phlebotomy and PA via waist-worn ActiGraph GT3X were assessed at baseline and end of study. Study variables included neighborhood walkability (car-dependent: Walk Score < 50 vs. walkable: Walk Score ≥ 50), prediabetes (FPG 100-125 mg/dL), and recommended PA (moderate to vigorous PA [MVPA] > 22 min/day). Generalized linear model with logit link results were reported as adjusted odds ratios (AOR) with 95% confidence intervals (CI). RESULTS: The sample (N = 114) was mostly female (88.6%), white (83.3%), college educated (73.7%), and on average 51.4 ± 1.0 years of age. At baseline, persons residing in car-dependent neighborhoods tended to have higher income than those in walkable neighborhoods. Neighborhood walkability interacted with household income at study entry to predict participants' ability to meet the MVPA goal at 12 months (AOR = 13.52, 95% CI: 1.86-119.20). Those from walkable neighborhoods had 67% lower odds of having prediabetes compared to those from car-dependent neighborhoods (AOR = 0.33, 95% CI: 0.10-0.87) at 12 months. CONCLUSION: Our findings corroborate previous research characterizing the relationship between neighborhood walkability, PA, and prediabetes status. Key drivers of this impact warrant further investigation in a study with a larger, more diverse sample.

Associations Between Physical Activity and Changes in Weight Across 7 Years After Roux-en-Y Gastric Bypass Surgery: A Multicenter Prospective Cohort Study.

OBJECTIVE: To examine associations of objectively-measured physical activity (PA) with changes in weight after roux-en-Y gastric bypass (RYGB) over 7 years. BACKGROUND: The contribution of free-living PA to surgery-induced weight loss and subsequent weight regain is not well understood. METHODS: Participants of a multi-center prospective cohort study of bariatric surgery were followed annually ≥7 years. Of 807 participants who underwent RYGB and were given an activity monitor, 649 (80%) had sufficient data for this report (78% female; median age 47 years; median body mass index 46 kg/m2). Mean daily steps, hours/day in SB and minutes/week in moderate-to-vigorous physical activity (MVPA) were determined at each assessment. Mixed models tested associations between PA measures and weight outcomes, controlling for sociodemographics, health status, and eating behaviors. RESULTS: Across follow-up, mean pre to postsurgery changes in PA were small, and mean postsurgery PA level was below PA recommendations for health (eg, 101 MVPA min/week 7 years postsurgery versus the ≥150 MVPA min/week recommendation). There was a dose-response association between more steps, less SB and more MVPA with greater weight loss. Steps and SB, but not MVPA, were also associated with weight regain. For example, participants in the highest versus lowest steps quartile lost 2.9% (95% confidence interval, 1.8-4.1) more of their presurgery weight and regained 5.4% (95% confidence interval, 2.4-8.3) less of their maximum weight lost across follow-up. CONCLUSIONS: Despite only small increases in objectively-measured PA level after RYGB, PA level was independently associated with weight outcomes of bariatric surgery throughout 7 years of follow-up. REPRINTS: Reprints will not be available from the authors.