By narrowing standards for what is permissible and strengthening the FDA's legal authority to act against misleading claims, the rules could curtail a trend in food marketing that has resulted in almost 40% of new products and a third of the $3.6 billion in food advertising over the last year featuring health-related messages.

Federal policy on health claims has been in limbo since 1984, when Kellogg's placed a message on its All Bran cereal noting the scientific evidence linking a high fiber diet to a reduction in colon cancer. Although the move was in apparent defiance of a longstanding FDA rule prohibiting all health-related messages on food products, the agency did not act.

Those rules made enforcement difficult and allowed what then-FDA Commissioner Frank E. Young last year referred to as "overly broad or otherwise unjustified" messages.