Polycystic ovary syndrome (PCOS) is a lifelong disorder affecting reproductive, metabolic, and psychological health. A healthy lifestyle and effective weight management strategies should underpin the treatment of PCOS. This case report documents the successful management of a Chinese patient with PCOS who was overweight and presented with oligomenorrhea and persistent adiposity. The patient was diagnosed using the Rotterdam criteria. The intervention was a 2-month program involving caloric restriction (1,350 kcal/day whole-food diet), progressive exercise titration (150–180 min/week of aerobic and resistance training), mindfulness practice, and metformin initiation after confirmed insulin resistance (HOMA-IR 3.67) resulted in clinically significant body composition improvements: fat mass was reduced by 5.0 kg, visceral adipose area was reduced by 44.7 cm², skeletal muscle was increased by 1.4 kg, and regular menstrual cycles (32 day interval) were restored following 5% weight loss––consistent with evidence linking this threshold to improved ovarian function. The combination of a structured lifestyle modification program with targeted pharmacotherapy offers a viable clinical approach for metabolic PCOS phenotypes, although further validation is required to ascertain long-term efficacy.