Any question answered...

I saw a nutritionist recently. She was of the opinion that it's total number so rather than 5 portions or whatever, aim for 25-30 different types of food for a day. Everything counts so porridge with blueberries and milk is say 3..

The idea is every food has something different to offer and even if you only have a tiny amount you get a little bit of that something. Like a food multivitamin.

But, like multivitamins, that's essentially unscientific codswallop.

The national advice is primarily based on if you can include 5 proper sized portions of fruit and veg (ideally veg but they included fruit cos people like it) it's actually quite hard to find room/recipe for much "unhealthy" - fats, excess carbs etc. I know that for example if I do some courgettes with whatever main, I won't be able to eat chips.

That's essentially the public health logic. The human body is remarkably good at synthesis of most essential things from a staple and basically unvaried diet - if you mix it around within a week or month it's fine. No need to get every vitamin and amino acid, every meal. The most common vitamin deficiency in this country is due to people being darker skinned and stuck inside all day!