Examining the Association between Intervention-Related Changes in Diet, Physical Activity, and Weight as Moderated by the Food and Physical Activity Environments among Rural, Southern Adults

Abstract

Background: Few studies have been conducted in rural areas assessing the influence of community-level environmental factors on residents' success improving lifestyle behaviors.

Objective: Our aim was to examine whether 6-month changes in diet, physical activity, and weight were moderated by the food and physical activity environment in a rural adult population receiving an intervention designed to improve diet and physical activity.

Design: We examined associations between self-reported and objectively measured changes in diet, physical activity, and weight, and perceived and objectively measured food and physical activity environments. Participants were followed for 6 months.

Participants/setting: Participants were enrolled in the Heart Healthy Lenoir Project, a lifestyle intervention study conducted in Lenoir County, located in rural southeastern North Carolina. Sample sizes ranged from 132 to 249, depending on the availability of the data.

Intervention: Participants received four counseling sessions that focused on healthy eating (adapted Mediterranean diet pattern) and increasing physical activity.

Potential moderating factors: Density of and distance to food and physical activity venues, modified food environment index, Walk Score, crime, and perceived nutrition and physical activity neighborhood barriers were the potential mediating factors.

Outcome measures: Diet quality, physical activity, and weight loss were the outcomes measured.

Statistical analyses: Statistical analyses included correlation and linear regression and controlling for potential confounders (baseline values of the dependent variables, age, race, education, and sex).

Results: In adjusted analysis, there was an inverse association between weight change and the food environment, suggesting that participants who lived in a less-healthy food environment lost more weight during the 6-month intervention period (P=0.01). Also, there was a positive association between self-reported physical activity and distance to private gyms (P=0.04) and an inverse association between private gym density and pedometer-measured steps (P=0.03), indicating that those who lived farther from gyms and in areas with lower density of gyms had greater increases in physical activity and steps, respectively.

Conclusions: Contrary to our hypotheses, results indicated that those living in less-favorable food and physical activity environments had greater improvements in diet, physical activity, and weight, compared to those living in more favorable environments. Additional research should be undertaken to address these paradoxical findings and, if confirmed, to better understand them.

Keywords: Built environment; Diet; Food environment; Lifestyle intervention; Physical activity.