The duration of a cutting phase depends on your individual goals and body composition. Generally, it's recommended to cut until you reach your desired level of leanness or until you notice diminishing returns in fat loss progress. It's important to listen to your body and avoid prolonged extreme calorie deficits, as it can negatively impact your metabolism and overall well-being. Once you've achieved your goals, transitioning to a maintenance phase or a gradual reverse dieting approach can help you maintain your progress.