HealthDay News — The U.S. Preventive Services Task Force (USPSTF) recommends clinicians screen all adults for obesity and refer patients with a BMI of 30 kg/m² or more to intensive multicomponent behavioral weight loss interventions.
Group weight management sessions, individual sessions, setting weight-loss goals, improving diet or nutrition, physical activity sessions, addressing barriers to change, active self-policing and maintenance of lifestyle changes are among strategies task force chair Virginia Moyer, MD, of Baylor College of Medicine in Houston, and colleagues suggested in the new guidelines.
The recommendations are the first updates USPSTF has issued on the topic since 2003, and are published online in Annals of Internal Medicine.
The task force reviewed new evidence on the benefits and harms of screening for overweight and obesity and determined that multicomponent weight-loss interventions could result in an average weight loss of 4 to 7 kg, as well as improve glucose tolerance and other physiologic risk factors for cardiovascular disease.
The new recommendations are graded class B, meaning there is a high certainty that the net benefit is moderate, though “[i]nadequate evidence was found about the effectiveness of these interventions on long-term health outcomes,” the researchers wrote, adding that the harms of screening and behavioral intervention for obesity are small.
The recommendations were based on data from 38 trials with a behavioral intervention, 18 with combination behavioral intervention and orlistat treatment, and three with a combination of a behavioral intervention and metformin treatment.
Results of the behavioral intervention-only trials indicated that patients who participated in the intervention lost a mean 1.5 kg to 7 kg (3.3 to 15.4 lbs.) vs. minimal or no weight in the control group at 12 to 18 months. Furthermore, those who participated in 12 to 26 intervention sessions during their first year lost an average 4 kg to 7 kg (8.8 lbs. to 15.4 lbs.) vs. 1.5 kg to 4 kg (3.3 lbs. to 8.8 lbs.) for those who participated in fewer than 12 sessions.
Behavioral interventions may also have the potential to reduce diabetes incidence, results from two of the trials that involved this method indicate — among overweight and obese patients with elevated plasma glucose levels diabetes incidence fell 30% to 50% during a two- to three-year follow-up period. Small improvements were noted in lipid outcomes, BP reduction and waist circumference, the researchers noted.
Combination treatment with orlistat and a behavioral intervention resulted in a mean weight loss of 2.6 kg (5.7 lbs), a mean 1.9-cm (0.75-inch) waist circumference decrease and a decrease in fasting glucose levels.
Although metformin is not approved in the United States for a weight-loss indication, participants in the trail that involved off-label use of the medication experienced a 3.4-cm (1.34-inch) decrease in waist circumference.
Adverse events in the behavior only interventions included reduced bone mineral density, increased fracture risk, injuries from increased physical activity and increased frisk for eating disorders. For trials involving medication, adverse events included possible risk for liver disease with orlistat and mild to moderate gastrointestinal adverse events after discontinuing treatment. There is a lack of long-term safety data available for orlistat, the researhcers noted.
“The USPSTF concludes with moderate certainty that medium- or high-intensity behavioral counseling interventions in the primary care setting to promote a healthful diet and physical activity have a small net benefit in adult patients without CVD, hypertension, hyperlipidemia or diabetes,” the researchers wrote.
Moyer VA et al. Ann Intern Med. 2012; doi:10.7326/0003-4819-157-5-201209040-00475.
Moyer VA et al. Ann Intern Med. 2012; doi: 10.7326/0003-4819-157-5-201209040-00486.