Total hip arthroplasty is a frequently performed and highly successful surgical intervention. It is done to relieve pain and improve function in people with advanced arthritis of the hip joint. Symptomatic osteoarthritis is the most common indication for surgery.The number of cases has increased significantly due to the rapidly increasing aging population worldwide. It is estimated that 0.33 million total hip arthroplasty (THA) are performed annually in the United States, and the demand for these surgeries will be 0.57 million in 2030. It is important to establish practical strategies to improve the quality of healthcare for patients undergoing THA and achieve earlier recovery and better outcomes, while also facilitating the reduction of the heavy economic burden associated with healthcare associated with the increased number of procedures. According to the current protocol for total hip arthroplasty, patients are kept in a fasting state from midnight to prevent the risk of pulmonary aspiration during surgery. This condition causes both physical and mental discomfort in patients. This is an old technique that has been practiced for many years. Patients experience a catabolic state after surgery, which can contribute to insulin resistance and hyperglycemia, which can worsen the stress response and prolong recovery time. Prolonged fasting in the perioperative period slows down metabolism and induces insulin resistance. Avoiding long-term fasting and metabolic satiety before surgery significantly reduces postoperative insulin resistance and also has beneficial effects on postoperative glucose and protein metabolism. Metabolic satiety prevents early feeding, preserving muscle mass and less hyperglycemia in patients. Adequate nutritional intake before and after surgery significantly reduces surgical stress and accelerates functional recovery. After whey is consumed, it passes quickly through the stomach and reaches the jejunum as intact proteins, and as clots form in the acid environment, the release of casein from the stomach is delayed. After peptic hydrolysis, peptides are released into the small intestine. It has been reported that the hydrolysis of whey in the small intestine is slow compared to other proteins, and their digestion and absorption occur over a longer intestinal length. It has been found that whey reduces food intake more at 90 minutes, but casein has a stronger effect later (at 150 minutes). It has many physiological functions, including regulating systems. However, these actions are not limited to whey proteins and peptides alone, but also result from the synergy between whey proteins and other whey components such as calcium. The effect of the proteins found in whey on satiety and food intake has an effect on the release of satiety hormones. Insulin plays a role in both short-term and long-term regulation of food intake. In the study conducted, whey plus carbohydrate drink was drunk 6 and 3 hours before surgery. Postoperative CRP (C reactive protein), albumin and insulin resistance were found to decrease significantly in those who drank whey. In a study conducted in which perioperative 2-hour fasting was administered to patients undergoing maxillofacial surgery, glutamine and oral carbohydrate solution were found to reduce postoperative insulin resistance.Whey, which will be used in this study, is easy to digest and absorb. Whey components contain significant amounts of milk proteins and their properties. The main protein of milk is casein, approximately 80% of the proteins in milk consist of whey, and the proteins in milk contain approximately 20% of the proteins. In this planned study, the effect of oral whey on postoperative surgical stress and inflammatory responses will be investigated by giving oral whey before total hip arthroplasty.