The Short Version
No scientific study has ever tested whether women sleeping naked next to partners lose weight faster than those sleeping clothed. The claim stitches together unrelated findings — a five-man brown fat study, neonate skin-to-skin research, and general sleep-quality data — into a speculative chain that no evidence supports as a whole. Every credible medical source consulted explicitly states sleeping naked does not directly cause weight loss. The added detail about a partner's presence has zero basis in any published research.