For a serious cut, then sure I can see getting really strict with your diet.
For everyday life though. Dude, you need to have some balance, and actually live your life, not be a slave to it. Eat basically healthy, getting 3 solid meals a day, and some healthy between meal snack feeds. Go lift, and grow.
There is nothing wrong with having a less than perfect day of nutrients. Just don't make it a habit. If your lifting hard enough your going to burn most of the fuel your putting in your body anyway.
Now if you'll excuse me, my pizza is getting cold.