That strongly depends on the job. If the company has to follow regulations to meet some security posture, wiping the OS (and all the security tools and configuration set up by IT) to put your own favored OS without matching the security requirements could wind up with you getting fired.
I don’t recommend making significant changes to activity levels at the same time as making diet changes. Weight loss comes from changing what you eat. Exercise is absolutely necessary for a healthy lifestyle, but it is not the major factor in weight loss. And increasing exercise behaviors can destabilize eating habits, making it harder to stick to any good changes you do make with either diet or exercise.