Food blogging represents a complex interweaving of “foodie” or gourmet interest in cooking with those of blog writing and photography. The majority of blogs use pictures taken by the author himself/herself and some of them focus specifically on food photography.
There are different types of Food blogging.
Recipes
Food/Restaurant Review
Food and Travel (Ethics and Culture)
Food Photography
As long as it is about food it is considered as food blog. Most often a food blog has overlapping elements of all or some of these elements. A blog is a personal journal and there is no real rule of writing a food blog.
Food Blog 