Changes in eating, physical activity and related behaviors in a primary care-based weight loss intervention.

OBJECTIVE: To examine changes in eating behaviors and physical activity, as well as predictors of weight loss success, in obese adults who participated in a 2-year behavioral weight loss intervention conducted in a primary care setting. DESIGN: A longitudinal, randomized controlled, multisite trial. SUBJECTS: Three hundred ninety obese (body mass index, 30-50 kg m(-2)) adults, ≥ 21 years, in the Philadelphia region. METHODS: Participants were assigned to one of three interventions: (1) Usual Care (quarterly primary care provider (PCP) visits that included education on diet and exercise); (2) Brief Lifestyle Counseling (quarterly PCP visits plus monthly lifestyle counseling (LC) sessions about behavioral weight control); or (3) Enhanced Brief LC (the previous intervention with a choice of meal replacements or weight loss medication). RESULTS: At month 24, participants in both Brief LC and Enhanced Brief LC reported significantly greater improvements in mean (± s.e.) dietary restraint than those in Usual Care (4.4 ± 0.5, 4.8 ± 0.5 and 2.8 ± 0.5, respectively; both P-values ≤ 0.016). The percentage of calories from fat, along with fruit and vegetable consumption, did not differ significantly among the three groups. At month 24, both the Brief LC and Enhanced Brief LC groups reported significantly greater increases than usual care in energy expenditure (kcal per week) from moderately vigorous activity (+593.4 ± 175.9, +415.4 ± 179.6 and -70.4 ± 185.5 kcal per week, respectively; both P-values ≤ 0.037). The strongest predictor of weight loss at month 6 (partial R(2)=33.4%, P<0.0001) and at month 24 (partial R(2)=19.3%, P<0.001) was food records completed during the first 6 months. Participants who achieved a 5% weight loss at month 6 had 4.7 times greater odds of maintaining a ≥ 5% weight loss at month 24. CONCLUSIONS: A behavioral weight loss intervention delivered in a primary care setting can result in significant weight loss, with corresponding improvements in eating restraint and energy expenditure. Moreover, completion of food records, along with weight loss at month 6, is a strong predictor of long-term weight loss.

Effect of lifestyle intervention on cardiometabolic risk factors: results of the POWER-UP trial.

OBJECTIVE: To investigate the effects of three weight loss interventions on cardiometabolic risk factors, including blood pressure, lipids, glucose and markers of insulin resistance and inflammation. We also examined whether categories of incremental weight change conferred greater improvements on these parameters. METHODS: This 2-year trial was conducted in a primary care setting and included 390 obese participants who were randomly assigned to one of three interventions: (1) Usual Care (quarterly primary care provider (PCP) visits that included education about weight management); (2) Brief Lifestyle Counseling (quarterly PCP visits plus monthly behavioral counseling provided by a trained auxiliary health-care provider); or (3) Enhanced Brief Lifestyle Counseling (the same care as described for the previous intervention, plus weight loss medications or meal replacements). The primary outcome was change in cardiometabolic risk factors among groups. RESULTS: At month 24, participants in Enhanced Brief Lifestyle Counseling lost significantly more weight than those in Usual Care (4.6 vs 1.7 kg), with no other significant differences between groups. Enhanced Brief Lifestyle Counseling produced significantly greater improvements in high-density lipoprotein (HDL) cholesterol and triglyceride levels at one or more assessments, compared with the other two interventions. Markers of insulin resistance also improved significantly more in this group throughout the 2 years. Collapsing across the three groups, greater weight loss was associated with greater improvements in triglycerides, HDL cholesterol and markers of insulin resistance and inflammation at month 24, but was not significantly associated with reductions in blood pressure, total cholesterol and low-density lipoprotein cholesterol at any time. CONCLUSIONS: Enhanced Brief Lifestyle Counseling, which produced the largest weight loss, was generally associated with the greatest improvements in cardiovascular risk factors. These findings suggest that an intensive weight loss intervention, delivered in a primary care setting, can help obese individuals improve some cardiometabolic risk factors.

Cost-effectiveness of a primary care intervention to treat obesity.

BACKGROUND: Data on the cost-effectiveness of the behavioral treatment of obesity are not conclusive. The cost-effectiveness of treatment in primary care settings is particularly relevant. METHODS: We conducted a within-trial cost-effectiveness analysis of a primary care-based obesity intervention. Study participants were randomized to: Usual Care (UC; quarterly visits with their primary care provider); Brief Lifestyle Counseling (BLC; quarterly provider visits plus monthly weight loss counseling visits) or Enhanced Brief Lifestyle Counseling (EBLC; all above interventions, plus choice of meal replacements or weight loss medication). A health-care payer perspective was used. Intervention costs were estimated from tracking data obtained prospectively. Quality-adjusted life years (QALYs) were estimated with the EuroQol-5D. We estimated cost per kilogram-year of weight loss and cost per QALY. RESULTS: Weight losses after 2 years were 1.7, 2.9 and 4.6 kg for UC, BLC and EBLC, respectively (P=0.003 for comparison of EBLC vs UC). The incremental cost per kilogram-year lost was $292 for EBLC compared with UC (95% confidence interval (CI): $219-$437). The short-term incremental cost per QALY was $115,397, but the 95% CI were undefined. Comparison of short-term cost per kg with published estimates of longer-term cost per QALY suggested that the intervention could be cost-effective over the long term (≥ 10 years). CONCLUSIONS: A primary care intervention that includes monthly counseling visits and a choice of meal replacements or weight loss medication could be a cost-effective treatment for obesity over the long term. However, additional studies are needed on the cost-effectiveness of behavioral treatment of obesity.