Lifestyle Changes Help Obese Lose Weight
Studies Show Diet, Activity, or Weight Loss Programs Can Help Severely Obese People Shed Pounds
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Lifestyle Interventions for Severe Obesity: What Works? continued...
At six months, weight loss in the group that began diet and exercise at the start was about 6 pounds higher -- 24 pounds compared to 18. But the delayed exercise group caught up.
After 12 months, 101 participants remained. "At 12 months there were no significant differences between groups in weight loss," Goodpaster says. The diet and exercise group lost about 27 pounds, while the delayed exercise group lost 22. The average BMI declined from about 44 to 39.
Both groups also had reductions in waist circumference and abdominal fat. They had improvement in insulin resistance, reducing their diabetes risk, he found.
Commercial Weight Loss Programs
In the second study, Rock randomly assigned 442 women who were overweight or obese to one of three groups:
- A group of 167 women was enrolled in a center-based commercial weight loss program.
- A second group of 164 women was assigned to a telephone-based commercial weight loss program.
- A third group with 111 women was assigned to a ''usual care" group which served as a comparison group.
Those in the comparison group received a consultation with a dietary professional who gave them diet and activity guidelines and meal plans. They had a one-hour educational session, then a monthly check-in by email or phone.
The others were given prepackaged foods free of charge plus all the features of the program, and $25 for each clinic visit. The program studied was the Jenny Craig program. Rock served on the advisory board for Jenny Craig from 2003-2004 but was not on the board when the study began. Jenny Craig supported the study, and University of California, San Diego funded it as a clinical trial.
The women's average age was about 44. BMIs ranged from 25 (barely overweight) to 40 (severely obese).
At 24 months, the study showed:
- Women in the center-based program lost 16 pounds.
- Women in the telephone-based program lost 14 pounds.
- Women in the usual care group lost 4.5 pounds.
"The telephone and the center group had no [substantial] difference in weight loss," Rock tells WebMD.