Cystic fibrosis transmembrane regulator (CFTR)-directed therapies, such as modulators, have transformed the medical management of people with CF, resulting in better lung function, weight, and body mass index in recent years. With improved nutrition status in people on CFTR modulators, the emphasis on a high-energy, high-fat diet (the legacy CF diet) is declining, with an increased focus on a healthy diet. The increased survival and median predicted age of people with CF have created a need for more attention to metabolic diseases, including hypertension, dyslipidemia, and cardiovascular diseases. The effects of modulators on extrapulmonary manifestations associated with CF, such as CF-related diabetes, CF hepatobiliary involvement, gastrointestinal tract disorders, and pancreatic manifestations, are currently unknown. Approximately 95% of people with CF qualify for treatment with a CFTR modulator. This review discusses the basics of CFTR gene mutations and changes in nutrition status related to treatment with CFTR modulators.