It is not typical of most people to plan out a week's or even, a month's meals.
Quite true - but there are quite a few folk here who plan their main meals on a weekly basis.
Personally, I love to improvise and cook more or less every main meal from scratch unless I'm very busy with something else (in which case its egg and oven chips!). I don't plan very much - I just buy a selection of ingredients and take it from there. I wouldn't really like to know what I'm going to be cooking and eating every day in advance. Boring!
What I do 'do' is plan recipes (often experimental) according to the ingredient for the current recipe challenge. I write quite a few pages of notes/diagrams/ideas and make sure I have the ingredient in question to hand.
And it's hard for an old grizzler like myself to deal with these guidelines as a single meal is puny by their definition. I'd be unhappy with anything, but a big meal. So, I eat a small breakfast and later in the day, one big meal, without a lot of snacking in between. I'm not a constant grazer.
I agree. The best thing to do is plan one main meal per day. Breakfast (if eaten) can be something healthy and simple (fruit/some type of unsweetened cereal or maybe eggs and toast). I always have eggs in stock.