MANY STUDIES HAVE linked the consumption of non-diet soda and fruit juices with added sugars to obesity and attendant risks of diabetes. But now a new study of more than 50,000 U.S. nurses dramatically points up these connections and should encourage the efforts of groups seeking to ban in-school sales of such drinks. As in the past, the sugar and soft-drink industries are in a swirl, arguing that all sorts of other factors are contributing to obesity and diabetes.

Still, the correlations in the study are disturbing. As reported by The Post's Rob Stein, the data showed that the women who gained the most weight were those who increased their consumption of non-diet drinks from one or fewer per week to one or more per day. Such women gained an average of 10.3 pounds, compared with an average of slightly less than three pounds for those who consumed one drink or less per week. In addition, those who had one or more drinks containing sugar or corn syrup per day were 83 percent more likely to develop Type 2 diabetes than those who drank less than one such drink per month.

You don't have to be an expert research analyst to conclude -- as does Walter C. Willett of the Harvard School of Public Health, who helped conduct the study -- that "putting down all that sugar is not a healthy thing to do. That's the bottom line." Dr. Caroline M. Apovian of Boston University, who wrote an editorial accompanying the report in the Journal of the American Medical Association, said the findings ought to prompt action by consumers, primary care providers and government to discourage consumption of such drinks. Kelly Brownell, director of the Yale University Center for Eating and Weight Disorders, concludes that "reducing soft drink consumption may be a powerful means of addressing the obesity crisis."

Health-conscious consumers already have started to shift from sweetened drinks to diet sodas and bottled water. So, too, should operators of vending machines in schools. The American Academy of Pediatrics recommended this year that schools eliminate sales of sweetened drinks -- and many school districts have. More should follow suit.