Structured programs that help overweight and obese people eat less and exercise more work, offering a rare bit of success in the battle of the bulge, U.S. researchers said.
Two studies published online Saturday by the Journal of the American Medical Association showed that people who took part in programs that included both dieting and exercise lost weight.
In one, people fared best when they started both an exercise program and a diet at the same time. In another, the team compared the commercial weight-loss program and meals from Nestle AG's Jenny Craig Inc with conventional care.
"Intensive lifestyle interventions using a behavior-based approach can result in clinically significant and meaningful weight loss," Bret Goodpaster of the University of Pittsburgh School of Medicine and colleagues wrote in the Journal of the American Medical Association. The studies were presented at the Obesity Society meeting in San Diego.
More than 72 million U.S. adults, or 26.7 percent of Americans, are obese, a growing threat to public health and a drain on the nation's healthcare system.
So far, drug companies have been largely unsuccessful at finding a magic pill that can melt the pounds off, and many promising treatments have been marred by safety concerns. The latest drug to fall was Meridia, Abbott Laboratories' weight-loss pill which the U.S. Food and Drug Administration ordered off the market Friday.
That leaves weight-loss surgery, a risky but successful approach, and behavior modification programs.
Goodpaster and colleagues studied the latter.
The team divided a group of 130 obese adults into two groups. One dieted and exercised for a year; the other dieted for the first six months, then added the exercise program, working up to an hour walk five days a week.
By the end of the 12 months, the group that started exercising first lost nearly 27 pounds (12 kg) and the group that delayed exercising lost about 22 pounds (10 kg).
Both groups also got slimmer waists, lost abdominal fat, had less fatty buildup in their livers, had lower blood pressure and saw improvements in the way their bodies processed sugar -- all positive signs of improvement in cardiovascular risk factors.
In the second study, Cheryl Rock of the University of California, San Diego, compared the Jenny Craig weight-loss program to standard counseling in 442 overweight or obese women who were put in one of three groups.
In one, the women attended classes at a weight-loss center; another group got weekly weight-loss counseling by telephone. Both groups also got free meals provided by Jenny Craig.
The third group got two weight-loss counseling sessions and had monthly contact with a dietitian.
After two years, more than half of the women in the weight-loss groups that received free Jenny Craig meals had lost at least 5 percent of their original body weight, compared with 29 percent of those who got usual care.
The findings "raise the possibility that if structured commercial weight-loss programs could be provided free of charge to participants, both retention and average weight-loss outcomes might be far better," Rena Wing of Brown University in Rhode Island said in a commentary.
Wing said insurance companies often cover the estimated $19,000 to $29,000 cost of weight-loss surgery, but not the cost of commercial weight-loss programs such as Jenny Craig, which costs $1,600 for 12 weeks of counseling and food.
"Providing commercial weight-loss programs free of charge to participants might be a worthwhile health care investment," Wing wrote.
Rock served on the advisory board for Jenny Craig, which helped pay for and provided food and services for the study.