A federal judge in Chicago yesterday ordered a halt to the making, distributing and selling of the increasingly popular "starch blocker" diet pills. He ordered seven major manufacturers to destroy all the millions of pills in their warehouses.

U.S. District Court Judge Nicholas J. Bua ruled that the pills are drugs and not foods as the manufacturers had claimed. They are therefore subject to the requirements for safety and effectiveness testing of the Food and Drug Administration.

"The human population of this country should not be used as guinea pigs by manufacturers attempting to cash in on so-called dietary weight control remedies," the judge said in his order.

Dennis Gronek, an attorney representing the seven companies, said he would appeal the ruling.

The starch blocker manufacturers say the pills are food because they are made from kidney beans. Natural substances in the bean, when concentrated, help block the digestive enzyme amylase. Thus, starch is passed through the body without being broken down and absorbed as calories, proponents claim.

Witnesses for the FDA position argued before Judge Bua in August that the drugs cause nausea, stomach pains and gas, vomiting and other symptoms of gastric distress. Dr. C. Wayne Callaway of the Mayo Clinic in Rochester testified that some people who took the pills had difficulty walking, and felt lethargic and confused.

He said the effects were so pronounced that they were arrested for drunk driving when they had not been drinking. The FDA now claims that 27 people may have been hospitalized by the effects of the blockers.

Gronek dismissed the FDA's claims of negative reactions. He said that any statement that 27 people were hospitalized as a result of using the products is a "bald-faced lie." He said most reports of adverse effects amount simply to people suffering some mild distress who happen to have taken the blockers at some time.

The links between taking the starch blockers and the patients' complaints are simply not documented, he said.

Gronek said that while the seven companies affected directly by the ruling are now barred from selling starch blockers, other companies would not be legally restricted from selling them.

U.S. Attorney Dan K. Webb disagreed. He said the effect of the ruling should be a nationwide ban on starch blocker sales. Some 160 million of the starch blocker pills were sold last year by the seven companies who were affected by the Chicago decision.

"The finding of the court is very simple," Webb said. "It is now beyond all question that starch blockers are a drug and cannot be marketed by anyone in this country till they are tested and approved by the FDA."

"That means anybody who would do that is violating the law," he said. "They would be subject to immediate legal action, including criminal action."

Yesterday's ruling was the latest event in a year-old battle between the FDA and the makers of the starch blockers, which took the form of open legal warfare on July 1, when the agency ordered a halt to the sale of all starch blockers, maintaining that they are drugs being sold without safety tests.

More than 80 percent of the companies that make and distribute starch blockers quit selling them then, according to FDA figures, but some companies did not, and the FDA followed up with raids on their warehouses, making 13 seizures and hauling in more than a million pills as of last week.

The seven companies then joined together to go to court to stop the FDA action. A three-day hearing was held in August before Judge Bua, and his ruling came yesterday afternoon in Chicago.

Gronek attacked the ruling as a "novel interpretation of what a food is," an interpretation unsupported by the FDA or other courts. He said it has been held consistently that a food is not defined by its "intended use," but simply by what it is--in this case, bean concentrate.

He said vitamins and protein supplements are more comparable to the starch blockers than the typical drug would be.

In his ruling, Judge Bua said that "substances used for food are those consumed either for taste, aroma, or nutritional value. It is clear that starch blockers are used for none of these purposes." He added that they are marketed in the same ways as drugs, not foods.