标题：Reducing Sugar-Sweetened Beverage Consumption by Providing Caloric Information: How Black Adolescents Alter Their Purchases and Whether the Effects Persist
摘要：Objectives. We examined the ways in which adolescents altered the type and size of their purchases of sugar-sweetened beverages (SSBs), together with whether the effects persisted after removing caloric information signs in stores. Methods. We used a case-crossover design with 6 stores located in low-income Black neighborhoods in Baltimore, Maryland, from 2012 to 2013. The intervention used 1 of 4 randomly posted signs with caloric information: absolute calories, number of teaspoons of sugar, and number of minutes of running or miles of walking necessary to burn off a beverage. We collected data for 4516 purchases by Black adolescents, including both baseline and postintervention periods with no signs posted. Results. We found that providing caloric information significantly reduced the number of total beverage calories purchased, the likelihood of buying an SSB, and the likelihood of buying an SSB greater than 16 ounces ( P < .05). After removing the signs, the quantity, volume, and number of calories from SSB purchases remained lower than baseline ( P < .05). Conclusions. Providing caloric information was associated with purchasing a smaller SSB, switching to a beverage with no calories, or opting to not purchase a beverage; there was a persistent effect on reducing SSB purchases after signs were removed. An important contributor to adolescent obesity 1–4 is the consumption of sugar-sweetened beverages (SSBs). SSB consumption is highest among minority adolescents; it is approximately 15% of their daily caloric intake. 5,6 Although American Health Association guidelines recommend that SSB consumption be limited to 8 to 12 ounces per day for children 7 to 18 years old, 7 Black adolescents appear to consume at least twice that much of SSBs daily. 6 Understanding the potential for environmental interventions, which are increasingly seen as essential for obesity prevention, 8 to motivate reductions in SSB consumption among groups at high risk of obesity is important. Clinical obesity interventions are not easily accessible to all adolescents, and most adolescents who begin obesity treatment do not complete it, 9 with poor and minority youths at even higher risk for discontinuing treatment. 10 One promising environmental strategy to reduce consumption of SSBs is to provide consumers with easily interpretable caloric information; this is the result of the empirical evidence that suggests that consumers significantly underestimate the amount of calories in the foods they consume, 11–13 and that consumer choices can be markedly affected by information. 14,15 Moreover, relative caloric information, such as the running minutes required to burn off a particular beverage (as opposed to absolute calories), may be more effective in reducing consumption. 16,17 Our previous work, 17 which was the only study on caloric labeling to focus on low-income Black adolescents, examined the effect of providing caloric information and found that providing this information in the form of a physical activity equivalent (e.g., minutes of running required to burn off a bottle of soda), relative to no information, significantly reduced the likelihood that an observed beverage purchase was an SSB and increased the likelihood of a water purchase. 17 However, our previous study was unable (1) to examine the decision to purchase any beverage or the size of beverage purchased; (2) to determine whether study participants understood or believed the caloric information, which was critical based on the research that suggested that information could only affect purchasing behavior if individuals noticed or perceived it 13,18,19 ; (3) to examine which type of caloric information was most effective (because of the small sample size); or (4) to examine whether exposure to caloric information had a persistent effect postintervention. These key unanswered questions from our initial study are important areas of inquiry that have not been previously addressed in the research. The previous literature related to the persistence or duration of information and behavior change is particularly scarce. A recently published theoretical framework that examined consumer responses to nutrition information on food labels posited that a label’s effect on purchasing might persist over time, even after the label was removed. 20 By contrast, empirical evidence from the literature on mass media campaigns for tobacco cessation suggested that the removal of information was associated with a decline in beneficial effects. 21–23 Our main purpose of this study was to identify the most effective modes of communicating SSB caloric information among Black adolescents to reduce the quantity, volume, and number of calories from SSB purchases. Our secondary aim was to examine whether providing caloric information had a persistent effect on behavior after it was removed. For our primary aim, we hypothesized that providing caloric information in an easily understandable format would reduce adolescent purchases of SSBs in 3 different ways: forgoing any beverage purchase, switching to a non-SSB, and switching to a smaller SSB. For our secondary aim, we hypothesized that caloric information would have an attenuated, but persistent effect, on beverage purchasing after the intervention ended.
