You do need to eat big to get big, but there comes a point of diminishing returns. I've eaten 5000 calories a day in the past but all it did was make me fat. And when you get fat it's a double-edged sword because with more fat deposits comes increased cortisol and estrogen production and thus a suppression of testosterone.
So what you need to do is eat just enough to be putting on about 2-3 lbs per month. I started this year in January weighing 210 lbs and this morning I was 229lbs. That's a gain of 19lbs in the space of 10 months, or nearly 2lbs a month. I'm bigger, leaner, and stronger as a result. Put it this way, at the beginning of the year I couldn't see my abs, now I can.
I'm eating 3,500 calories a day BTW.