On leisure trips rarely. Sometimes McDonalds breakfast if I'm going to be doing a road trip and want something I can eat in the car while driving. Note: this rule may be suspended if I do a lot of drinking and need some late night bites
On business trips frequently. A lot of my work involves hearings at immigration courts which are located in the middle of nowhere. Lumpkin, GA (nearest city Columbus), Jena, LA (nearest cities Alexlandria or Monroe) are just two of them. These are not hot beds of dining activity and as I'm there for work I don't want to scope out restaurants. My last visit to Alexandria there was a Chili's in the parking lot which was perfect for eating in the room while I worked. Also, a lot of these places only involve the lowest tier chain hotels so I'll skip breakfast and grab McDonalds for my drive to court.