Welcome to the Ranch
There ain't no such thing as a 2D array in Java™.. What you have been told about is an array of arrays.
The code you have posted is difficult to read because you haven't availed yourself of the space available (which is unlimited), and squashed the { against the preceding line where they are difficult to find. If you use the indenting convention where you have { at the end of a line, separate the { from the line by several spaces.
Why have you marked everything
static? That suggests to me that you are not creating objects. Why have you not got a diet class which you create objects from? I would suggest you need to go back to the drawing board and create a diet class, with methods like recordNextMeal, getCaloriesForWeek and overridden toString.