I didn't have a very strict diet. I live with my parents and I'm in college, so I don't have the cash to buy excellent foods all the time. I focused on a lot of meats high in protein. Lots of chickens, lots of pastas, fast food every few days for extra calories. I stayed away from super greasy and fatty foods, 90% of the time. No soda, very little junk food like Candy and sweets.
So basically I was focusing more on quantity than quality, but I didn't get too bad.
I focused on both, the scale going up shows progress to an extent, but I also made sure I wasn't gaining too much fat. I took a lot of photos and always made sure to see my progress from month to month.