According to a new study, obese patients who took the diet drug Meridia and received intensive weight-loss counseling, lost twice as much weight as patients who only took the drug.
As almost one third of Americans are considered overweight, the U.S. Food and Drug Administration regards any diet pill effective if it enables a 200-pound (90-kg) person to lose at least 10 pounds (4.5 kg) in a year.
Although most obese people need to lose far more than 10 pounds (4.5 kg), doctors always say that even a moderate weight loss has health benefits.
At present Meridia and Xenical are the only diet drugs licensed by the FDA.
In the study of Abbott Laboratories drug Meridia, researchers found that when the drug was combined with 30 weight-loss counseling sessions lasting 90 minutes each, the treatment produced an average weight loss of 27 pounds (12.1 kg) for 60 volunteers.
The counseling ranged from advice on healthier eating habits to other behavioral changes that can reduce weight.
Another 55 patients in the study, took the drug but received no counseling and lost 11 pounds (5 kg).
A third group of 55 volunteers, who only received counseling, lost an average of 15 pounds (1.7 kg).
At the start of the study the patients in general weighed about 240 pounds (108 kg); the study was sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases.
The researchers, led by Thomas Wadden of the University of Pennsylvania School of Medicine, also found that obese patients who received both the drug and counseling lost the most when they recorded how much food they were eating.
Those who regularly logged their consumption shed 49 pounds (18.1 kg) versus 17 pounds (7.7 kg) among those who did not track what they ate.
A separate study, also published in the same journal, examined the experimental diet medicine Acomplia.
This study was financed by Sanofi-Aventis the drug's manufacturer.
In this study participants on average weighed 192 pounds (96 kg) and had high cholesterol.
Thirty-three percent of patients who ate a low-calorie diet and took 20 milligrams of Acomplia every day for a year lost an average of 15 pounds (6.9 kg) and three inches (7.1 cm) from their waistlines.
Their "good" cholesterol levels also climbed.
Placebo recipients lost three pounds (1.5 kg) and an inch (2.4 cm) from their waists, but more than a third of the study's 1,036 volunteers dropped out of the study, complaining mostly of depression, anxiety and nausea.
Susan Yanovski of the National Institute of Diabetes and Digestive and Kidney Diseases, describes the weight loss from Acomplia as "moderate" and comparable to other drugs.
She warned that while weight loss seems to improve risk factors such as blood pressure, no study has yet demonstrated conclusively that any weight-loss treatment actually reduces the risk of heart disease.
And also she says it remains uncertain whether obese people who lose weight are ultimately as healthy as people who were never obese.
The Meridia study is published in the New England Journal of Medicine.