When RDAs are changed FDA determines whether or not the revision is sufficient to require a labeling change. The latest revisions are being done in seven stages and won't be completed until 2000. RDAs are being expanded updated and reshaped to reflect current scientific evidence. The aim is to help prevent chronic diseases including cancer heart disease and osteoporosis. The first revisions involved five nutrients and for the first time set upper limits for consumption of some of them. Two new age categories 51 to 70 years old and 70 years and older were added. The project is a joint U.S./Canadian effort with the goal of harmonizing food labels between the two countries improving marketability.