Achieving Long-Term Weight Loss in Patients in Clinical Practice Settings: Insights From the POWER Trials Contents More than one-third of U.S. adults are obese, having a body mass index (BMI) of 30 or more. The extra weight increases a person’s risk factors for heart disease, including high blood pressure, type 2 diabetes, and dyslipidemias, such as high cholesterol. Weight loss of just 5 percent of body weight in overweight or obese adults can lower these risk factors and improve health. The clinical practice setting offers an ideal environment in which to promote and deliver weight loss interventions to overweight and obese patients. New results from research funded by the National Heart, Lung, and Blood Institute (NHLBI) show that when physicians and their staff engage their patients in weight loss programs, the patients can lose 5 percent or more of their starting body weight and keep it off for 2 years. The POWER Trials The Practice-Based Opportunity for Promotion of Weight Reduction (POWER) trials were three separate, 5-year randomized control trials (RCTs) funded by the NHLBI. The trials sought to identify effective interventions that can be used in clinical practice settings (primary care and general internal medicine practices) to help obese patients who have one or more cardiovascular disease risk factors lose weight and maintain the loss. Results from two of the studies were published in the New England Journal of Medicine in November 2011. Results from a third study are pending. To evaluate a range of approaches to determine what may be most effective to achieve weight loss in a clinical practice setting, the three trials differed in their interventions. However, they shared several key features: - The primary outcome measure was change in body weight 2 years after the start of the study.
- The weight loss interventions were feasible for delivery in routine clinical practice (they had reasonable costs and were potentially reimbursable).
- The interventions incorporated evidence-based behavioral approaches.
- Study participants had a BMI of 30–50 kilograms/meters2 (kg/m2), and a body weight less than or equal to 400 pounds (lb), or 182 kg.
- Participants had at least one additional cardiovascular risk factor (such as hypertension, hypercholesterolemia, or diabetes), in addition to obesity.
POWER Hopkins (Johns Hopkins University) What was the study? Six primary care practices in the Baltimore area participated in the study. At these clinics, 46 primary care providers (PCPs) enrolled 415 participants, who were recruited though physician referral, brochures, and targeted mailings. - The mean age of the participants was 54 years; 64 percent were female, and 41 percent were African American. Participants had a mean BMI of 36.6 and mean weight of 104 kg (229 lb).
- All participants had at least one or more cardiovascular risk factors (hypertension, hypercholesterolemia, or diabetes).
- Participants had to have regular access to a computer and basic computer skills (they could enter data into a Web site and send and receive e-mail).
Participants were randomly assigned to one of three groups: - Remote intervention group. This group received weight-loss support via phone, Web, and e-mail from trained weight loss coaches, without any face-to-face contact.
- The Web site included learning modules and self-monitoring tools and graphs (to record weight, minutes of exercise per day, and calories consumed per day).
- The e-mails were automated monthly messages that summarized progress.
- In-person intervention group. These participants received support through individual and group sessions with coaches, in addition to receiving remote support via phone, Web, and e-mail. Participation in group sessions was encouraged but not mandatory, and individuals had the option of phone contact versus in-person support, to reflect a typical clinical practice setting.
- Control group (usual medical care). Weight loss was self-directed. This group received weight loss brochures and a list of recommended Web sites promoting weight loss.
Participants in the two behavioral weight loss intervention groups were encouraged to lose 5 percent of their weight within 6 months and to maintain the reduced weight throughout the 2-year study period. - Weight loss coaches were employees of Johns Hopkins University or Healthways. They were trained on topics such as behavioral theory, basic nutritional and exercise guidelines, and motivational interviewing techniques. They provided encouragement and reinforced key behavioral recommendations.
- PCPs played a supporting role. They reviewed progress reports on the participants in the intervention groups and provided basic guidance at routinely scheduled visits.
- The intervention recommendations included:
- Calorie recommendation:
1,200 kcal/day if <170 lb
1,500 kcal/day if >170 lb and <220 lb
1,800 kcal/day if >220 lb and <270 lb
2,200 kcal/day if >270 lb - Dietary pattern: Dietary Approaches to Stop Hypertension (DASH); 7–12 servings of fruits/vegetables and 2–3 servings of low-fat dairy daily; reduced sodium intake; ≤25 percent of calories from fat.
- Physical activity goal: Build to ≥180 minutes/week of moderate intensity physical activity in bouts ≥10 minutes in length.
- Web site log-in: At least weekly.
- Self-weighing: At least weekly during weight loss; daily during maintenance.
- Tracking: Daily tracking of food intake and physical activity.
What did the study find? - Forty-one percent of participants in the in-person intervention group and 38 percent in the remote intervention group lost 5 percent or more of their initial body weight, compared with 19 percent of participants in the control group.
- Mean weight loss at 2 years was 5.1 kg in the in-person support group, 4.6 kg in the remote support group, and 0.8 kg in the control group.
- Use of the Web site was high, whereas participation in group sessions was low.
- There was no difference in weight loss between the two intervention groups at any time point. Participants in both of the intervention groups achieved substantial weight loss with or without in-person coaching sessions.
POWER-UP (University of Pennsylvania) What was the study? Six primary care practices (three urban and three suburban) in the Penn Medicine system participated in this study. The clinics enrolled 390 participants, who were recruited though physician referral and self-referral from in-clinic advertisements. - The mean age of the participants was 51 years; 80 percent were female, and 39 percent were African American. Participants had a mean BMI of 38.5 and mean weight of 108 kg (238 lb).
- All participants had at least two of five components of metabolic syndrome (a large waistline, high triglyceride levels, low HDL cholesterol levels, high blood pressure, and high fasting blood glucose).
Participants were randomly assigned to one of three groups: - Brief lifestyle counseling group. This group was offered monthly sessions (25 total) with lifestyle coaches who instructed participants about behavioral weight control.
- Enhanced brief lifestyle counseling group. This group was offered the monthly sessions and had the additional option of using meal replacements (such as liquid shakes or meal bars) or taking weight loss medication (such as orlistat).
- Control group (usual medical care). This group received printed educational materials.
Participants in the two behavioral weight loss intervention groups were encouraged to lose 5 percent of their weight within 6 months and to maintain the reduced weight throughout the 2-year study period. - The primary care providers met with all participants four times a year to discuss coexisting illnesses, and spent about 5–7 minutes reviewing the participant’s weight change.
- The lifestyle coaches were staff (primarily medical assistants) at the clinics who had good patient rapport. None had experience with weight management. Both PCPs and lifestyle coaches received 6–8 hours of training.
- The treatment recommendations for all three groups included:
- Calorie goal:
1,200–1,500 kcal/day if <250 lb
1,500–1,800 kcal/day if ≥250 lb - Physical activity goal: >180 minutes/week of moderate intensity activity
- “Aim for a Healthy Weight” NHLBI handouts
What did the study find? - Nearly 35 percent of participants in the enhanced brief lifestyle group lost 5 percent or more of their initial body weight, compared with 26 percent of participants in the brief lifestyle counseling group, and 21.5 percent in the control group.
- Mean weight loss at 2 years was 4.6 kg in the enhanced brief lifestyle group, 2.9 kg in the brief lifestyle counseling group, and 1.7 kg in the control group.
- Monthly counseling sessions combined with the option to use weight loss medication or meal replacements (such as liquid shakes or meal bars) helped about one-third of obese participants lose a significant amount of weight and keep it off for 2 years.
Be Fit, Be Well (Washington University and Harvard University) The study was conducted at three community health centers in the Boston area. The participants were predominantly low-income and from racial and ethnic minority groups, and had been diagnosed with high blood pressure (hypertension). The study compared usual care with lifestyle modification intervention in which health coaches provided support though phone calls and bimonthly group sessions and the patients set goals, monitored their progress, and received additional support. Results from this study are pending. Key Steps for Health Professionals - Health care providers are uniquely positioned to screen their patients for obesity and to engage their patients in a dialogue about their weight and the health risks associated with it.
- Health care providers can help overweight and obese individuals understand that even modest weight loss (5 percent of body weight) can lead to clinically important reductions in heart disease risk factors.
- By building a partnership, health care providers can help individuals develop weight loss goals that they can achieve and sustain.
- Health care providers should encourage individuals to:
- Adopt healthy lifestyle behaviors (balance calories consumed with calories burned).
- Make healthy food choices, such as those recommended in the research-based DASH dietary plan.
- Engage in regular physical activity.
- Spend less time in sedentary activities such as watching television or computer games.
POWER Study Resources - Appel L.J., Clark J.M., Yeh H.C., et al. (2011). Comparative effectiveness of weight-loss interventions in clinical practice. New England Journal of Medicine, 365(21):1959–68.
- Wadden T.A., Volger S., Sarwer D.B., et al. (2011). A two-year randomized trial of obesity treatment in primary care practice. New England Journal of Medicine, 365(21): 1969–79.
- Practice-Based Opportunity for Promotion of Weight Reduction Trials (POWER Trials) (overview)
- NIH studies find long-term weight loss methods for clinical practice (news release)
Popular NHLBI Materials - Aim for a Healthy Weight Provider Kit
- Aim for a Healthy Weight: 3 Steps to Initiate Discussion About Weight Management With Your Patients
- Aim for a Healthy Weight Patient Booklet
- Aim for a Healthy Weight: Keep an Eye on Portion Size Z Card
- Aim for a Healthy Weight Tools (BMI calculator, Menu Planner, Portion Distortion)
- At-A-Glance: Facts About Healthy Weight
NIH Obesity Resources - “Overweight and Obesity” From the NHLBI Health Topics Web site
- NHLBI Obesity Research Web site
- The Weight-control Information Network, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH
- Strategic Plan for NIH Obesity Research
Other Resources - ChooseMyPlate.gov, U.S. Department of Agriculture (USDA)
- Dietary Guidelines for Americans, 2010 (USDA)
- 2008 Physical Activity Guidelines for Americans (U.S. Department of Health and Human Services)
- Let’s Move! Initiative
December 2011 |
