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!
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.
https://nutrisense.wordpress.com/2013/07/10/dr-mercola-turns-the-food-pyramid-on-its-head-it-sure-beats-the-usda-food-pyramid/