Abstract:
Background: Glucagon-like peptide-1 (GLP-1) receptor agonists can produce rapid weight loss, but this loss is frequently accompanied by disproportionate lean mass loss, especially during the early phase of GLP-1 treatment. Physical activity, particularly resistance training, is the most effective behavioral strategy for enhancing fat reduction while preserving lean mass during weight loss, yet little is known about whether remote virtual health programs can deliver the structured, strength-focused support needed to achieve high-quality weight loss in this population.
Methods: This work used a quasi-experimental design to evaluate whether a 12-week virtual GLP-1 lifestyle companion program that includes physical activity coaching is associated with increased weight loss and preservation of muscle mass among adults with obesity who initiated GLP-1 therapy for weight loss ≤8 weeks prior to baseline. A total of 245 adults received either a virtual GLP?1 lifestyle companion program (n=151) or usual care (n=94). The GLP-1 lifestyle companion program provides virtual health coaching, GLP?1–specific peer support groups, digital tools for meal logging and behavior tracking, AI?based nutrition support, and a tailored resistance? and function?focused physical activity plan, plus asynchronous messaging with an exercise coach certified in personal training. Body composition was measured using home bioelectrical impedance analysis scales, and psychosocial and behavioral outcomes were self-reported. Outcomes analyses were conducted using linear mixed?effects models fit by restricted maximum likelihood. Our primary focus was the timepoint × group interaction, which tests whether changes over time differ between participants in the GLP-1 lifestyle companion program and control group.
Results: Among the primary analytic sample (n=245), mean age was 42.9 years, 72.7% were female, and mean BMI was 36.3 kg/m², with no significant differences in these characteristics between the GLP?1 lifestyle companion and usual care groups at baseline (all p > 0.05). Participants in the GLP?1 lifestyle companion program lost approximately 6.0% of their baseline body weight versus 3.3% in the control group (between?group difference 2.8%, p < 0.001). Compared with usual care, GLP-1 program participants also experienced a greater decline in body fat percentage (−3.3% vs. −1.6%, p < 0.001), a greater increase in muscle mass percentage (+0.6% vs. +0.2%, p < 0.01), and greater improvements in weight loss self-efficacy, well-being, physical functioning, depression symptoms, and anxiety symptoms.
Conclusions: Personalized, virtually delivered physical activity programming as part of a GLP-1 lifestyle companion program may meaningfully improve the quantity and quality of weight loss during GLP-1 therapy as well as improve patient psychosocial and behavioral outcomes.
