As the debate regarding how best to address the rising rates of obesity among children and adults in the United States continues to evolve it may be helpful to review exactly how consumers are occupying the time in which they are eating and drinking. Data published by the U.S. Department of Agriculture’s Economic Research Service highlight primary and secondary eating occasions, the activities consumers are engaging in during those occasions, and correlate the activities to the body mass index of the participants. A review of the data highlights a single activity that appears to stand out — television watching.

This insight is important, because as smart-phones and tablet computers become more ubiquitous, and as the opportunities to view content become dramatically more numerous, the challenge of convincing consumers to adopt a more active lifestyle may grow. It also highlights the role individual behavior plays in the relationship between diet, activity and obesity.

Published in early November, the Economic Research Service’s study, titled "How much time do Americans spend on food?," reviewed time use patterns related to food for consumers above the age of 15. The report found that on an average day over a three-year period between 2006 to 2008 Americans spent about 2.5 hours eating or drinking. Slightly less than half of that time, 67 minutes, was spent in eating and drinking as a "primary" or main activity. The remaining time was spent in eating and drinking while doing something else considered secondary such as watching television, driving, preparing meals for others, working, or traveling to a meal destination such as a restaurant and waiting to eat.

Those who engaged in secondary eating or drinking while driving, working, grooming or during meal preparation and clean up had lower-than-average B.M.I.s, while those who engaged in secondary eating while watching television had higher-than-average B.M.I.s. Obese individuals spent just over three hours watching television per day, about 37 minutes more than those with normal weight, according to the study.

Against this backdrop, it’s worthwhile to look at the highly intense efforts at lowering obesity rates by finding ways to cut intake on sugar-sweetened beverages or fast food. But as a recent study in the Archives of Pediatrics & Adolescent Medicine shows, the banning of sugar-sweetened beverages in schools does not appear to reduce overall consumption among adolescents. The study found that just banning soda in schools did not limit consumption and even a ban of all sugar-sweetened beverages in schools, while limiting access, did not limit overall consumption.

Researchers from the University of Illinois at Chicago examined state policies that banned all sugar-sweetened beverages in schools compared with states that banned only soda or had no beverage policy for in-school purchases to determine whether the policies were associated with reduced in-school access and purchase of sugar-sweetened beverages. The authors also sought to determine if these polices were associated with reduced overall consumption of sugar-sweetened beverages among adolescents.

The study included 6,900 students from public schools in 40 states, who were sampled during their fifth and eighth grade years, spring 2004 and 2007, respectively, and had completed questionnaires about their in-school access to and purchase of sugar-sweetened beverages, as well as their overall consumption of sugar-sweetened beverages. The authors found that the proportion of students who reported in-school sugar-sweetened beverage access and purchasing were similar in states that banned only soda (66.6% and 28.9%) compared with states with no beverage policy (66.6% and 26%, respectively).

The complexity of the obesity problem may not be overstated, but many governmental and public health efforts to date have focused on singular causes and ignored the broad range of issues that contribute to the problem. Future progress will require efforts that focus on changing behavior rather than trying to control what people eat.