Article of the week -February 11th 2016

Why is this study important? As a follow-up to last week's article on the impact of policies to reduce sugar content in drinks, we will continue on the theme of policies to reduce sugar sweetened beverage intake. This is a hot topic currently as data suggest that calories from sugar sweetened beverages (SSB's) contribute adverse health outcomes in youth including weight gain and cardiometabolic risk factor clustering. More importantly, randomized controlled trials that target SSB reduction have shown positive effects on child and adolescent health. For example, a trial published in the New England Journal of Medicine found that an promotional intervention that advocated for choosing water or calorie-free drinks in place of SSB's delivered to families with overweight and obese adolescent, prevented weight gain in youth, particularly among Hispanic youth. With mounting evidence that modifying SSB intake may lead to better health outcomes in youth, population-based strategies or policies that could nudge families away from SSB's would be attractive to governments interested in reducing the global burden of obesity and chronic diseases in children and adolescents.

Labelling as a option to reduce SSB intake.  Labelling foods or menu items became a very hot topic a few years ago, when the US congress passed a law requiring chain restaurants to provide nutritional information on their menus. The city of New York received more attention than others for implementing the policy and early results were not overly exciting. Consumers were aware of the labels, but only a small portion (<20%) used the labels to change their menu choice. However, among those that did, they reduced their calorie intake by ~100 kcals for the meal purchased. As we saw last week, a seemingly meager 100kcal reduction per meal, could prevent hundreds of thousands of cases of type 2 diabetes. Based on this information, a group of Canadian scientists from the University of Waterloo designed a study, that was published this week in the journal Pediatrics, to evaluate the impact of SSB labelling on knowledge and behavior of parents of children. The hypothesis they had was: "that a warning label would be more likely to increase perceptions of the health harms of SSBs and reduce purchase intentions for SSBs relative to calorie labels or no labels. This research has the potential to inform regulatory efforts in states and municipalities considering SSB warning label policies."

How did they test the study hypothesis? Led by fellow CIHR Applied Health Chair, Dr. David Hammond, his team recruited ~3300 parents of children 6-11 yrs of age were randomly assigned to one of 6 conditions: two control labels; one with no label and one with simple calories and 4 intervention labels with various health warnings. After seeing the warning, they were provided with a simulated vending machine task and then asked to complete a short survey regarding various factors that might influence their decision about purchasing SSB's (See table 2 here).

What did they find? Compared to calorie-only or no label conditions, no one health-messaging label was better than another for altering knowledge or intended purchase of an SSB, therefore the authors collapsed all 4 health labels. When a health label was added to an SSB bottle however, parents were ~33% less likely to chose an SSB for their child (40% vs 60%) and convinced parents that SSB's were unhealthy for their child (Table 4). All of these changes were statistically significant. Most participants felt that a warning label would change their beliefs about the health benefits of SSBs and 73% supported labelling of beverages.

Why is this important?  As we try to build sandbags to defend the children and teenagers in our country against obesity and it's many consequences, we will need to rely on interventions that have the greatest impact and one's that nudge us to make the right choices. This study provides some evidence that providing a label that contains a health message on pop bottles, will change a parent's perception of how healthy the item is and more importantly, it will dramatically shift the purchasing behavior of the parent.

Limitations of the study. The study is strengthened by the large sample size, the randomized nature of the experiment and the use of multiple messages to influence behavior. The study however was a simulation, therefore it is unclear if this information will be as effective in the grocery store where people are distracted, influenced by sales tactics by the store and (perhaps more importantly) screaming children as they are marching down the aisles. The large effect seen in this simulation however (i.e. reduction in desire to purchase SSBs), makes me interested in seeing this type of study extended to a real-world setting on a larger scale. So, when you are voting for someone advocating for health policies, consider those who are aware of these nudge-grounded interventions that may have a population health impact at a relatively low cost.