When you're lifting weights and trying to build up a little muscle mass, the common mantra is "eat more protein". The problem tends to be though that more protein = more fat... and when you're eating enough to make your body do all the things you really want it to do, you have plenty of calories for your body to burn/build, so all that lame fat just gets stored under the skin covering up all of those pretty bumps you've been trying to build.
Just today though I realized the formula for deciding what's "okay" to eat and what's not: The GRAMS of protein in the food must be higher than the PERCENTAGE of the USRDA of fat.
This is perfect... it avoids the "can't eat fat" thing (you do need some)... it ensures an intake of at least double the USRDA of protein, and ensures you don't go over your "normal" fat intake, and is incredibly easy to manage when looking at any nutrition facts item in the store.
...with this discovery, my plan to take over the world is almost complete... ;)