Food environments are relevant to recruitment and adherence in dietary modification trials

Abstract

Few studies have examined the built environment's role in recruitment to and adherence in dietary intervention trials. Using data from a randomized dietary modification trial of urban Latina breast cancer survivors, we tested the hypotheses that neighborhood produce access could act as a potential barrier and/or facilitator to recruitment, and that a participant's produce availability would be associated with increased fruit/vegetable intake, one of the intervention's targets. Eligible women who lived within a higher produce environment had a non-significant trend towards being more likely to enroll in the trial. Among enrollees, women who had better neighborhood access to produce had a non-significant trend toward increasing fruit/vegetable consumption. As these were not a priori hypotheses to test, we consider these analyses to be hypothesis generating and not confirmatory. Results suggest that participants’ food environment should be considered when recruiting to and assessing the adherence of dietary intervention studies.

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

“…Our findings are the opposite of Wedick et al 10 and Feathers et al 11 who found that a more supportive food environment (e.g., greater access to Green Carts, farmers’ markets, and supermarkets) was associated with improved intervention-related outcomes. However, these prior studies included interventions focused on reducing dietary fat and increasing fruit, vegetable, and fiber consumption, and both were set in urban areas of the Northeastern United States.…”

“…In correlational analyses, we generally found small but statistically significant improvements in diet and PA among those who lived in less favorable food and PA environments, contrary to our original hypothesis, and to previous findings in urban settings. 10, 11, 13, 42 In adjusted analyses, which controlled for baseline values of outcomes and socio-demographic variables, findings again indicated that those who lived in less favorable environments lost more weight and increased PA to a greater degree than those in healthier, more supportive environments. Our results could suggest a hypothesis to be tested in rural settings: when resources are less plentiful, intrinsic motivation may influence an individual’s ability to make healthy changes to a greater degree than supportive environments and community resources.…”

“…Two studies have examined the hypothesis that dietary behavior change interventions may be more effective when participants live in areas where more healthful foods are available 10, 11 with the potential causal mechanism being that individuals who live in areas with more healthy eating opportunities are more likely to increase healthy eating behaviors. Both studies found greater adherence to dietary interventions among those with improved access to healthy food sources such as supermarkets, farmers’ markets, and green carts.…”

“…Both studies found greater adherence to dietary interventions among those with improved access to healthy food sources such as supermarkets, farmers’ markets, and green carts. 10, 11 Four additional studies have examined factors in the perceived and objectively-assessed built environment related to PA, generally finding improvements in PA among those participants who lived in more favorable PA environments. 12–15 However, both the diet- and PA-focused studies 10–15 were set primarily in urban areas, further supporting the need to determine whether the food and PA environment may moderate the effect of diet and PA interventions among rural residents.…”

Does Effectiveness of Weight Management Programs Depend on the Food Environment?

“…And Feathers et al. (), in a secondary analysis of data from an intervention designed to increase fruit and vegetable intake, found no statistically significant relationship between intervention adherence and density of retail produce locations near home for the 53 out of 70 women enrolled in the intervention for whom data were available. A key limitation in the literature is that existing research is based on relatively small sample sizes that may lack the statistical power to reliably measure treatment effect heterogeneity.…”