Moderators of intervention dose effects on diet quality and physical activity changes in a church-based,...

Many community-based lifestyle interventions targeting African Americans have reported positive effects on participants' dietary choices and physical activity habits. However, these effects vary and not all participants will have outcome changes. Moderation analysis can help explain differential effects observed, but are not often reported. Hence, the objective of this secondary analysis was to explore potential moderators of intervention dose effects on diet quality and physical activity outcomes in an effective lifestyle intervention. Delta Body and Soul III, conducted from 2011 to 2012, was a 6-month, church-based, multicomponent, educational intervention designed to improve diet quality and increase physical activity in rural Southern African American adults. Generalized linear mixed models were used to determine associations among indicators of intervention dose received by participants, potential moderators and health outcome changes. Results indicated only three baseline characteristics-employment status, food shopping frequency and individual with primary responsibility for meal preparation-moderated the effects of education session attendance on diet quality changes. No evidence for moderation of exercise class attendance effects on physical activity changes was found. Thus, this culturally targeted, multicomponent lifestyle intervention did induce positive health changes in participants with a range of sociodemographic characteristics and food shopping and eating behaviors.