Mayor Michael Bloomberg proposed prohibiting food service establishments from selling sweetened drinks larger than 16 ounces, but diet sodas, dairy products like and alcoholic beverages would be exempt.
Opponents of the plan say soda lovers can simply buy two 16-ounce soda to bypass the ban.
Brian Elbel of the New York University School of Medicine and colleagues evaluated the potential effect of the ban policy on the consumption of calories from beverages at fast-food restaurants.
"We combined data from two separate studies in which receipts were collected from consumers at fast-food restaurants, including 1,624 receipts that listed a beverage, excluding milk shakes, from three different fast-food restaurants in four separate cities -- New York City; Newark, N.J.; Philadelphia; and Baltimore -- from 2008 through 2010," the researchers said. "With these receipts, the corresponding survey from both studies, and data from the Web site of each restaurant, to calculate calories in each beverage."
The researchers found if 100 percent of consumers switched to 16 oz. and 0 percent purchased 32 oz. the resulting change would be 63 fewer calories consumed via sugary beverages.
Only if 80 percent or more of consumers purchased 32 oz. drinks would calories from sugar-sweetened beverages purchased increase, the researchers said.
The findings were published in a letter to the New England Journal of Medicine.