Published by trade group American Beverage Association (ABA), the new report is part of the industry's commitment to provide information on progress made during the three-year phase-in of the initiative.
The national guidelines, which were implemented last year, call for industry to provide lower-calorie, smaller-portion and nutritious options in schools.
These include 100 percent fruit juice, low-fat milk and bottled water in middle schools, as well as diet sodas, calorie-capped sports drinks, enhanced waters, and low-calorie teas in high schools.
They were created through industry collaboration with the Alliance for a Healthier Generation, a joint initiative by former President Bill Clinton and the American Heart Association (AHA), which set out science-based nutritional guidelines for foods and drinks sold in schools.
According to ABA's new report, which measures beverage shipments to schools during the 2006-2007 school year as compared to 2004 shipments, there has been a 41 percent cut in total calories contained in these beverages.
In addition, there has been a 45 percent reduction in shipments of full-calorie sodas to schools during that time.
The report shows that the average high school student consumed less than half a can of full-calorie soft drinks a week in school (5.9 ounces), compared to a little more than a full can a week (12.5 ounces) in 2004.
In contrast to the drop in full-calorie soft drinks, shipments of waters are up by 23 percent since 2004.
"We're cutting calories in schools and making wholesale change to the beverage choices in schools across America," said Susan Neely, president and chief executive officer of the American Beverage Association.
"The hard work of our companies and bottlers is already making a real difference reducing the calories students drink in school.
We're delivering."
The reduction in soft drink sales in schools is also likely a result of new restrictions implemented on sales of these products in schools by local school districts.
Limits on soda sales have come into effect over the past few years in a number of states, including Alabama, Arizona, California, Connecticut, Kentucky and New Jersey.
Furthermore, under terms of the Child Nutrition and WIC Reauthorization Act, as of July 1, 2006 every school that participates in the school lunch or school breakfast program- the large majority of US schools- was required to have a local wellness policy in place.
The policy, designed to address the problem of childhood obesity, requires that schools set nutrition standards for all foods sold in school, including in vending machines, a la carte lines, and school stores.
According to public health groups such as the Center for Science in the Public Interest (CSPI), despite the significant voluntary efforts made by industry to provide healthier options in schools, real progress will only be made if new regulations are put in place.
"Given that two-thirds of high school beverage sales are still sugary drinks, voluntary industry action and a patchwork of state and local policies are not enough to solve the problem.
The time has come for Congress to pass Senator Harkin's bill to update and strengthen the national standards for foods and drinks sold in schools," said CSPI nutrition policy director Margo Wootan.
Senator Harkin's Child Nutrition Promotion and School Lunch Protection Act, which was re-introduced this year, aims to update federal regulations governing the sale of snacks and other foods sold on school grounds.
ABA will publish another progress report next fall.
To access the current report, click here .