Pilot Findings from a Randomized Controlled Trial Targeting Sugar-Sweetened Beverage Behaviors

Background: Low health literacy and increased sugar-sweetened beverage (SSB) consumption are two broad public health concerns facing the United States. For example, it is estimated that 90 million Americans have insufficient literacy skills (IOMC, 2004) and low health literacy is associated with poorer health outcomes (Berkman et. al., 2011). Furthermore, SSBs contribute about 80% of added sugars in the diet (Nielsen & Popkin, 2004) and have been associated with poor health outcomes, including obesity, type II diabetes, bone fractures, dental caries, and coronary heart disease. Despite these findings, there is limited research related to how to effectively decrease SSB intake among adults. Additionally, there have been few studies investigating health literacy interventions that target health behaviors in community settings (Allen et.al, 2011).

Objective: As guided by the Theory of Planned Behavior (TPB) and constructs of health literacy, this 5-week, 2-arm randomized controlled pilot trial, used mixed methods to examine the effects of an intervention to decrease SSB (SipSmartER), as compared to a matched-contact control condition targeting physical activity (Move More). The primary aims of this pilot project were to evaluate participant's feedback through process and summative evaluation as well as evaulate intervention content and/or delivery through process evaluation by staff tracking for quality improvements. Secondary aims included the assessment of changes in theorized mediating variables and health behaviors among participants.

Methods: Twenty-five participants (mean age = 42±14 years, mean BMI = 34.3±7.5 kg/m₂, 19 females, 12 African Americans, 9 (high school education) residing in Roanoke, VA were randomized to either SipSmartER (n=14) or Move More (n=11) to begin the 5-week intervention. Inclusion criteria consisted of participants being 18 years of age or older, English speaking, consuming greater than 200 kcal/day of SSB, and being without medical conditions in which physical activity would be contraindicated. Both 5-week interventions included two interactive small group sessions (Weeks 1 & 5) and three support telephone calls (Weeks 2, 3 & 4). Pre-post data was obtained using previously validated instruments including Beverage Intake Questionnaire (Bev-Q), Theory of Planned Behavior constructs addressing SSB and physical activity, media literacy, subjective numeracy, Stanford Leisure-Time Activity Categorical Item (L-CAT), and quality of life. Descriptive statistics, ANOVA, and regression models were used in data analysis.

Results: Although SSB consumption decreased more among the SipSmartER participants (-257±622.6 kcal/day) than Move More (-200±404.6 kcal/day) there were no significant group by time differences. However, among all participants, changes in TPB constructs significantly predicted changes in SSB (R²=0.592; F=2.485; p=0.080) and physical activity behaviors (R2=0.621; F=2.813; p=0.056). Participant and staff feedback were very positive, ranging from 4.2-5.0 on a 5-point likert scale that included questions about intervention organization, flow, effectiveness, engagement, and enjoyment. Favorite themes that emerged with SipSmartER participants when asking about small group sessions included, realizing how much sugar is found in SSBs, understanding the health risks associated with drinking too much sugar, realizing how much sugar was being consumed during the day, and learning about better alternatives.

Conclusion: Findings suggest promise for the piloted intervention to reduce SSB consumption through targeted TPB and health literacy strategies. This pilot study has allowed further refinement and execution of a larger trial that includes a larger sample and longer study duration (i.e. 6-months) and follow-up period (i.e. 18-months).