Association between neighborhood food environments and bariatric surgery outcomes.

Background: Individual characteristics associated with weight loss after bariatric surgery are well established, but the neighborhood characteristics that influence outcomes are unknown.

Objectives: The objective of this study was to determine if neighborhood characteristics, including social determinants and lifestyle characteristics, were associated with weight loss after bariatric surgery.

Setting: Single university healthcare system, United States.

Methods: In this retrospective cohort study, all patients who underwent primary bariatric surgery from 2008 to 2017 and had at least 1 year of follow-up data were included. Patient-level demographics and neighborhood-level social determinants (area deprivation index, urbanicity, and walkability) and lifestyle factors (organic food use, fresh fruit/vegetable consumption, diet to maintain weight, soda consumption, and exercise) were analyzed. Median regression with percent total body weight (%TBW) loss as the outcome was applied to examine factors associated with weight loss after surgery.

Results: Of the 647 patients who met inclusion criteria, the average follow-up period was 3.1 years, and the mean %TBW loss at the follow-up was 22%. In adjusted median regression analyses, Roux-en-Y gastric bypass was associated with greater %TBW loss (11.22%, 95% confidence interval [8.96, 13.48]) compared to sleeve, while longer follow-up time (-2.42% TBW loss per year, 95% confidence interval [-4.63, -0.20]) and a preoperative diagnosis of diabetes (-1.00% TBW loss, 95% confidence interval [-1.55, -0.44]) were associated with less. None of the 8 neighborhood level characteristics was associated with weight loss.

Conclusions: Patient characteristics rather than neighborhood-level social determinants and lifestyle factors were associated with weight loss after bariatric surgery in our cohort of bariatric surgery patients. Patients from socioeconomically deprived neighborhoods can achieve excellent weight loss after bariatric surgery.