Motivational Interviewing for Weight Loss: A Review of Evidence-Based Outcomes in Overweight and Obese Adults

Abstract

Obesity is a significant clinical problem affecting 41.9% of adults in the United States, with profound implications for individual health and healthcare economics. Standard weight loss interventions, often limited to pharmacological treatments and dietary guidance, frequently fail to achieve sustained adherence and meaningful longterm outcomes. This quality improvement (QI) project evaluated the integration of motivational interviewing (MI), a patient-centered counseling strategy, into routine clinical practice at Innovafusion, a medically supervised weight loss clinic in Aubrey, Texas. The aim was to enhance adherence to lifestyle modifications, promote intrinsic motivation, and improve weight loss outcomes among adults aged 18–65. Using a retrospective and prospective comparative chart review design, baseline data from standard care alone were compared to outcomes from MI-enhanced interventions over an 8-week period. Weight loss was measured using bioimpedance analysis, and adherence and motivation were assessed with the Weight Efficacy Lifestyle Questionnaire–Short Form (WEL-SF). Although no statistically significant difference in mean weight loss was observed between groups (t(88) = 0.37, p = 0.714), participants receiving MI demonstrated improved motivation and self-reported adherence behaviors. These findings suggest that MI addresses psychological and behavioral barriers that impede sustained weight loss. Clinical recommendations include routine MI integration to strengthen patient self-efficacy and adherence. Future studies should assess MI\u27s longterm impact and explore objective adherence measures to further inform evidence-based obesity management