This prospective observational study aims to evaluate longitudinal changes in sarcopenia-related parameters in patients undergoing bariatric surgery. Obesity and rapid weight loss following bariatric surgery may lead to changes in muscle mass, muscle strength, and physical performance, which are important components of sarcopenia.

Participants will be evaluated before bariatric surgery and during postoperative follow-up visits. Muscle thickness will be assessed using ultrasonography of the femoral muscles. Muscle strength and physical performance will be evaluated using handgrip strength, the 5-meter walk test, and the five-times sit-to-stand test.

The study aims to investigate the effects of bariatric surgery on muscle function and physical performance over time and to contribute to the early identification of sarcopenia risk in this patient population.