The only "fattening" thing I have ever had at a Benihana's is the oil they use to keep the food from sticking to the grill.
They have lean red meat, chicken and shrimp there. Then they serve you grilled veggies with your meal and you can choose white rice or fried rice. That is the standard dinner - unless it has changed in the last 10 years?
That is when you sit around the grill though - never gone to the bar and had sushi?