12 Months later: Motivational interviewing plus nutrition psychoeducation for weight loss in primary care

Motivational interviewing (MI) weight-loss interventions have garnered much attention, particularly in primary care. Few studies, however, have examined long-term outcomes of MI for weight loss in primary care. This study sought to examine the longer-term outcomes of a combination approach comprising MI and nutrition psychoeducation (MINP) with a publically available web-support component (i.e., livestrong.com).

Thirty-one adults with overweight/obesity were enrolled in a 3-month MINP treatment delivered in primary care by medical assistants. Weight, blood pressure, and depression (beck depression inventory) were assessed at baseline and 1-year following treatment cessation (i.e., 15 months total).

Participants' average BMI was significantly lower 12-months following treatment. Approximately one-third of participants (34.8%) maintained 5% or more weight loss. Participants also experienced significant decreases in diastolic blood pressure, resting heart rate, and depression symptoms, but not systolic blood pressure or waist circumference.

The scalable (2.5 h total) MINP intervention delivered in primary care by medical assistants resulted in significant weight (medium effect size) and psychological improvements 12 months later. These findings complement previous RCT findings that MI or nutrition psychoeducation interventions, delivered separately, resulted in small weight loss effects after 12 months, with 5% and 17% of participants, respectively, maintaining 5% weight loss. It remains unclear, however, if implementing MI in primary care for weight loss is cost effective beyond providing nutrition psychoeducation alone.

The clinical trial registration number is NCT02578199.

IV, uncontrolled trial.