I really don't know who in the world first started blogging about food. Have heard it's the Japanese, which would not be surprising.
My online searches led to an interesting archived page by Dave Siegel - he blogged every meal in 1996. My, it's a blast from the past - the early days of the Internet - gosh, does anyone remember VRML?
Ah, those were the days when I actually could be bothered crafting websites by hand-typing HTML, and "View Source Code" was something you did when you envied a certain webpage's layout.
But back to Dave's 1996 food diary - there are no photos and long descriptions of dishes or recipes, but Dave includes memorable quotes, many of which are quite funny.