I take protein shakes and chicken/rice meals into work with me every day.
The chicken and rice nobody seems to bother or ask about it, lots of other people bring in food in tupperware, salads and the like, so it's seen as pretty normal.
The protein shakes on the other hand, and the occasional MRP seem to bring out the curiosity, ignorance, and sometimes downright stupidity in some people.
Guy at work (untrained, unhealthy, typical poorly-dressed twink) came up to me once as I was necking my 40g of very tasteful strawberry-flavoured whey and proceeded to lecture me that I would eventually suffer liver failure if I drank too much of "those shakes". Another one (female) told me that her brother "used to" drink protein shakes, he was "bigger" me, but now isn't big anymore because he "had a heart attack which was caused by all the protein". She then went outside for a cigarette.