In clinical observations, we have found that children with pectus excavatum generally do not have as good nutrition as normal children, and are not as plump. This may be related to the deformity of the chest indentation. We know that the normal cross-section of the thorax on a CT scan is oval-shaped, with the heart and lungs located behind the sternum. In children with pectus excavatum, the sternum is compressed backward toward the spine, which deforms and even pushes the heart completely to one side. This compression of the heart limits the blood's ability to fully return to the heart, and may even prevent the valves from closing completely, leading to valve insufficiency. As a result, both cardiac and pulmonary functions are somewhat impaired. Therefore, 80% of children with pectus excavatum experience exercise intolerance, meaning they cannot run as well as normal children, which also indicates poorer physical fitness and, comparatively, a lesser appetite. Recent studies have found that children with pectus excavatum also have slightly weaker immune functions, and their digestive and absorption capabilities are not as good as those of typical children. Poor exercise capacity and digestive function ultimately lead to poorer nutrition in children with pectus excavatum, making them less plump than normal children.