The HSPH Prevention Research Center developed the Planet Health curriculum for middle school students.

The HSPH Prevention Research Center developed the Planet Health curriculum for middle school students.

Lowered “time-price” of food to blame for rising obesity, says HSPH prevention expert

August 30, 2011

HSPH Prof. Steven Gortmaker believes that there is a simple explanation for the globally skyrocketing rates of obesity in recent decades. It is now easy to obtain fast and cheap food at all hours of the day and night, giving eating a much lower “time-price” than in previous generations. People are exercising at about the same rate that they were 20 years ago, Gortmaker, professor of the practice of health sociology and director of the Harvard School of Public Health Prevention Research Center, told an HSPH audience on July 19, 2011 as part of the School’s Hot Topics series, but the food environment they face every day has changed.

Constantly eating and drinking has become the norm, Gortmaker said. It is easier than ever to get cheap, high-calorie food and sugary beverages at all hours of the day and night, and kids are particularly vulnerable. Aggressively targeted by marketers of unhealthy foods and beverages, and surrounded by vending machines and fast food restaurants during the school day, unhealthy choices become their default.

“We need to alter the environment where children spend their time so that it’s easy to make healthy diet and physical activity choices,” Gortmaker said. “You can’t just leave it to individual choice.” He said a good start would be to take unhealthy products out of vending machines at schools and make sure free water is available.

Sugar-sweetened beverages are a unique nutritional villain. They can pack many calories yet don’t appear to satiate the appetite like other foods. But consuming just an extra 150 calories a day—the amount found in a typical regular soda—can lead to an extra 7.5 pounds of weight gain over the course of a year, and 15 pounds over three years, Gortmaker said. This weight gain adds up slowly over time and can lead to health problems and increased health care costs.

Gortmaker favors a national excise tax on sugar-sweetened beverages. In a study published in the August 25, 2011 edition of the journal The Lancet, he and his co-authors estimate such a tax would produce cost savings (produce more savings in future health cares costs than it cost to implement the tax). In addition, states can generate substantial revenue. He said recent calculations that they have done indicate a state like California could bring an extra $1.5 billion per year after implementing a $0.01 per ounce excise tax on sugar sweetened beverages. He also called for restricting companies’ ability to take a tax deduction for marketing costs when advertising non-nutritious foods to children.

Citing the successes that Planet Health, the middle school curriculum that the HSPH Prevention Research Center developed, has had in lowering obesity among girls and reducing the amount of time both boys and girls spent in front of the television, Gortmaker stressed the importance of reaching kids when they are young.

“Never before have our children been so obese,” he said. “We don’t really know the consequences because we have never been here before.”

Public health practitioners also have more work to do in helping time-crunched and budget-strapped adults make healthy choices in the real world, Gortmaker said. Both fresh and microwaved frozen vegetables, for example, can be quick and affordable alternatives to a fast food drive-through, he said. And don’t forget water as a primary beverage – Boston and Cambridge have good-tasting and high-quality water and you can’t beat the price.

– Amy Roeder