Washington ? Consumer advocates and others have complained bitterly in recent years that the Food and Drug Administration has veered from its scientific roots, making decisions on controversial matters – such as the emergency contraceptive “Plan B” – on political rather than scientific grounds.

Now comes a test of just how rational the public wants the FDA to be.

Later this week, the agency is expected to release a formal recommendation that milk and meat from cloned animals should be allowed on grocery store shelves. The long-awaited decision comes as polling data to be released this week show that the public continues to have little appetite for such food, with many people saying the FDA should keep it off the market.

The FDA decision is based on a substantial cache of data from rigorous studies, all of which have concluded that milk and meat from cloned animals is virtually identical to such products from conventional animals. Scientists have also been unable to detect health problems in laboratory animals raised on clonal food.

By contrast, studies have found that consumers’ discomfort with the idea of eating food from clones is largely based on vague emotions. Indeed, polls have repeatedly found that the public understands little about what cloning really is.

That raises the issue: Should decisions such as this one be based solely on science, or should officials take into account public sensitivities, which may be unscientific but are undeniably real?

Regulators and leaders of the handful of companies poised to enter the cloned-food market say this is a chance for the government and the public to hew to the facts.

“There is no science-based reason” to withhold clone-derived meat or milk from the market or to require that they be labeled as such, FDA scientists conclude in a report in the Jan. 1 issue of the journal Theriogenology.

But others say people cannot help but be emotional about food, and those feelings deserve consideration – if for no other reason than because ignoring them could weaken confidence in the food supply.

“There is more to this issue than just food safety,” said Susan Ruland of the International Dairy Foods Association, which represents such major companies as Kraft Foods and Dannon. The organization’s member companies are concerned that sales of U.S. dairy products could drop by 15 percent or more if the FDA allows the sale of meat and milk from clones.

“There’s a real trust in milk as a wholesome provider of core nutrition in your diet,” Ruland said. “You don’t want to fool around with that.”

Scientists make clones from single cells taken from animals they want to replicate. The process involves growing a cell into an embryo in a laboratory dish, then transferring the embryo to the womb of a surrogate mother animal. The resulting critter is a genetic twin of the animal that donated the starter cell.