By Daniel Weintraub
An intriguing study of the sugar content of popular soft drinks to be published Wednesday suggests that soda often contains more fructose than commonly believed, and fountain drinks at fast food restaurants have more sugar than advertised on nutrition content disclosures.
The study, published in the journal Obesity, was done by three University of Southern California researchers led by Dr. Michael Goran, director of the Keck School of Medicine’s Child Obesity Research Center.
The researchers collected samples of Coke, Pepsi, Sprite and other soft drinks and sent them to a lab that determined the amount of sugar overall in each drink while also breaking down the sugar content into portions of fructose, glucose and sucrose.
Bottled samples of Coke, Pepsi and Sprite had about the amount of sugar advertised — about 95 percent to 100 percent of the 36 to 41 grams per 12 ounces the samples were supposed to contain.
The bottled samples of Dr. Pepper and Mountain Dew, meanwhile, were found to contain 87 percent to 92 percent of the sugar advertised on the label.
Fountain drinks sampled at McDonalds and Burger King consistently had more sugar than advertised on the company’s websites. The samples had between 101 percent and 128 percent of the amount of sugar they were supposed to contain.
Cokes purchased at McDonalds and Burger King, for example, had 38 grams of sugar per 12 fluid ounces, compared to the 30 grams advertised by McDonalds and 32 grams by Burger King.
The researchers speculated that the discrepancy might be explained by an expectation that customers will dilute their drinks with ice, thus lowering the percentage of sugar in the contents. But if that is the case, they said, the fast-food companies should disclose that their numbers assume a certain amount of dilution.
Even though none of the bottled sodas were found to contain more sugar than advertised, they did contain more fructose than commonly assumed, the researchers wrote.
The researchers said it is commonly believed that the sugar in beverages sweetened with high fructose corn syrup contains 55 percent fructose and 45 percent glucose. The distinction is important because the two sugars are digested in different ways by the body, and the ingestion of fructose is believed to lead to more weight gain than an equivalent amount of glucose, the authors wrote.
The sugar in the samples of bottled soda contained 64 percent to 65 percent fructose, the researchers found.
“Our results suggest that more testing of actual vs. reported sugar content of sugar-sweetened beverages are in order in general, and in terms of fountain drinks, there should be information on the fast food company in-store menus and websites regarding whether the nutrition facts reflect displacement by ice,” the paper said.
“Considering that the average American drinks 50 gallons of soda and other sweetened beverages each year, it is important that we have more precise information regarding what they contain, including a listing of the fructose content.”
To download the entire paper, click here.