Mayor Michael Bloomberg is proposing a ban on the sale of large sodas and other sugary drinks in the city's restaurants, delis and movie theaters in the hopes of combatting obesity - an expansion of his administration's efforts to encourage healthy behavior by limiting residents' choices. The proposal - expected to be announced formally on Thursday in a City Hall briefing - would take 20-ounce soda bottles off the shelves of the city's delis and eliminate super-sized sugary soft drinks from fast-food menus. It is the latest health effort by the administration to spark accusations that the city's officials are overstepping into matters that should be left in the hands of individual consumers. "There they go again," said Stefan Friedman, spokesman for the New York City Beverage Association, who called the proposal "zealous" in a statement. The New York City Health Department's unhealthy obsession with attacking soft drinks is again pushing them over the top. The city is not going to address the obesity issue by attacking soda because soda is not driving the obesity rates. But City Hall officials, citing a 2006 study, argue that sugary drinks are the largest driver of rising calorie consumption and obesity. They note that sweet drinks are linked to long-term weight gain and increased rates of diabetes and heart disease. The administration's proposal would impose a 16-ounce limit on the size of sugary drinks sold at food service establishments, including restaurants, movie theaters, sports venues and street carts. The ban would apply only to drinks that contain more than 25 calories per 8 ounces. It would not apply to diet soda or any other calorie-free drink. Any drink that is at least half milk or milk substitute would be exempted. The ban, which could take effect as soon as March, would not apply to drinks sold in grocery or convenience stores that don't serve prepared food. Establishments that don't downsize would face fines of $200 after a three-month grace period. The proposal requires the approval of the city's Board of Health - considered likely because its members are all appointed by Bloomberg. Under the three-term mayor, the city has campaigned aggressively against obesity, outlawing trans-fats in restaurant food and forcing chain restaurants to post calorie counts on menus. The mayor has also led efforts to ban smoking in the city's bars, restaurants, parks and beaches. Bloomberg often cites the city's rising life expectancy numbers as proof the approach is working, but his efforts have drawn criticism from others who accuse him of instituting a "nanny state." His administration has tried other ways to make soda consumption less appealing. The mayor supported a state tax on sodas, but the measure died in Albany, and he tried to restrict the use of food stamps to buy sodas, an idea federal regulators rejected. City Hall's latest proposal does not require approval beyond the Board of Health, although public hearings will be held.