this may sound like heresy, but
I could give two shits about what arnold says. His "encyclopedia of bodybuilding" is not worth the paper it is printed on. The man was a genetic freak who was both overtrained and overdrugged, but at the end of the day, genetics are what set the great ones apart from mere mortals.
For nearly everyone (except those with lactose intolerance problems), milk (either 1 or 2 percent) should be the cornerstone of any bulking cycle. It is very, very difficult to consume the amount of calories nessecary for growth from just solid foods. Milk combined with a protein powder is almost essential in any anabolic regimen. Lactose is one the best forms of carbohydrate out there and milk protein is one of the only non-meat sources for a complete, biologically usable protein, (which soy is not).