This study looks at how **nutrition and muscle health** affect people with Cystic Fibrosis (CF), a disease that affects the lungs and makes it hard to breathe. The study will compare different ways of measuring body health, including Dual Energy X-ray Absorptiometry (DXA), which uses X-rays to look at body composition. We will also check how people's feelings and other factors might affect their nutrition. The study will examine **body and nutrition** measures and how they relate to lung health in adults with CF.
- The study includes adults with CF and different lung health levels.
- Participants should not have had certain recent medical treatments or surgeries.
- No new weight loss drugs or surgeries six months before joining.