Chronic daily activation of preproglucagon (PPG) neurons in two brainstem regions — the nucleus tractus solitarius and intermediate reticular nucleus — produced robust, sustained weight loss in obese mice through reduced meal size and food intake. These neurons showed distinct input patterns but convergent brain-wide projections, and their total number inversely correlated with weight gain. The breakthrough lies in demonstrating that chronic stimulation of these specific neural populations bypasses the accessibility limitations of current GLP-1 receptor drugs, which cannot effectively cross the blood-brain barrier to reach most brain GLP-1 receptors. This represents a potential paradigm shift for obesity treatment, as it identifies a direct neural pathway that could be therapeutically targeted without systemic drug delivery challenges. The sustained hypophagia occurred without notable adverse effects, addressing a major limitation of current appetite suppressants. While promising, this mouse study requires validation in primates and humans, where brainstem anatomy and neural circuits may differ. The approach could theoretically be implemented through deep brain stimulation or viral gene therapy vectors, though such interventions would face significant technical and safety hurdles in clinical translation.