Cystic fibrosis is a genetic disorder that affects the lungs and digestive system, causing thick mucus buildup that leads to frequent lung infections and breathing issues. Other symptoms include sinus infections, poor growth, and infertility in males. The document recommends a high-calorie and high-fat diet for cystic fibrosis patients, including cheese, fish, meat, nuts, fatty milk, rice, pasta, potatoes, white bread with cream or oil added, fruits and vegetables, and fat cream and sugar to provide vitamins and calories. Antibiotics are also used to treat lung infections associated with cystic fibrosis.