The first controlled study comparing behavior modification with drugs as methods for achieving weight loss has found not only that those using behavioral techniques do better over a long period of time, but also that those using only behavior modification do better than patients combining the psychological techniques with drugs.

"Our big hope was that by combining [drugs and behavior modification] we'd get the more rapid weight loss of the drugs" and then the better maintenance of weight loss associated with modifying eating habits, said Albert J. Stunkard, professor of psychiatry at the University of Pennsylvania.

Stunkard's study, presented here this week at the 101st annual meeting of the American Psychiatic Association, involved 145 persons in the Williamsport, Pa., area, who averaged 60 percent above their ideal weight.

The patients were divided into five groups - those using drugs alone in group therapy, those using behavior modification alone, those using the two combined, those receiving drugs alone from a private physician and a control group not receiving any treatment.

At the end of the first 16 weeks, those in the combined treatment group and the drug group had each lost at average of 25 pounds. Those using behavior modification alone lost 17 pounds, while those using drugs with monthly monitoring by a private physician lost 14 pounds and the control groups gained a pound.

Eight weeks later those in the combined treatment group had lost a total of 32 pounds each; those in the mediation group were down 30 pounds and those in the behavior modification group had lost 24 pounds. Those taking the drugs under the direction of a private physician had not lost any more weight than they had at 16 weeks, and the control group had gained four pounds.

The big advantage for persons in the behavior modification group was apparent at the six-month follow-up session when they had regained a mean of only two pounds. Those on medication had regained a mean of 9.8 pounds, and those in the combined group had regained 14.5 pounds.

The behavior modification consisted of having the patients keep extremely detailed records of how, where, why and what they ate, and with whom they ate it. The patients were then taught how to change their eating habits, learning how to avoid or control the situations and stimulations that were enticing them to overeat; some were eating as often as 12 times a day.

Stunkard said he cannot explain why the combined group did not do as well over the six-month period as the behavior modification group. In an interview, however, he theorized, "If the person loses weight with the drug he may attribute it to the drug and not to the behavior change. Then when he begins to regain he may get demoralized" and return to the habits that caused him to become obese in the first place.

Stunkard called the finding that those taking the drug in a group situation did better than those taking it under individual supervision "enormously important. It's a real breakthrough in the whole use of drug therapy."

The researcher said that although he is not sure why one group did better than the other, the finding indicates that the value of some drugs may depend on the conditions under which they are administered.