Head and neck cancer (HNC) remains a major global health issue. It is closely linked to smoking, alcohol use, and HPV infection. Nutritional and metabolic factors significantly influence surgical outcomes in these patients, especially when undergoing extensive resections and microsurgical free flap reconstruction. This comprehensive review aims to evaluate how perioperative nutritional status-particularly body mass index (BMI), serum albumin and prealbumin levels, and enteral vs. oral feeding strategies-affects complication rates, wound healing, surgical duration, and overall recovery. Poor nutritional status is associated with increased complication rates, prolonged surgery, impaired wound healing, and higher perioperative mortality. Both high and low BMI negatively impact surgical outcomes. Obesity is linked to protracted surgery and increased blood loss, while underweight patients have higher perioperative mortality. Optimizing perioperative nutrition is important for improving surgical outcomes in HNC patients. A multidisciplinary approach is necessary to tailor nutritional support and enhance recovery. Further research should focus on long-term weight management strategies and identifying biomarkers predictive of surgical success.