Your diet should be following the mypyramid.gov nutritional dietary reference intakes(DRI). Any other diet unless instructed by a dietary physician, or your doctor, isn't healthy. With the DRI you are allowed to eat a proportioned size of lean steak, as long as it meets your daily calorie needs.
What type of diet are you on that makes you ask if you can eat steak? If your diet restricts meat then NO! A weight lose diet yes you can eat steak!