I don't think you live in a parallel universe but i find your thought process that if everyone you know does it then it becomes an unwritten rule and you have to do it.
The vast majority of people eat a lot of sugary shite. Do you feel uou need to becayse they do? The vast majority also like a drink on a weekend. Do you feel you need to drink because they do? That these are also unwritten rules to be followed?
I've never been carb heavy. I don't and never have eaten breakfast. If I was going to I'd have some scrambled eggs, an omelette, some cheese and ham, or some full fat yoghurt and berries. I do not feel I should eat cereal or toast because many others do. My husband and daughter can do so if they wish.
For lunch I will eat a salad, egg, tuna, cheese, ham, whatever. Most places which sell sandwiches sell salads. I am not perceived as a weirdo for not chosing the sandwich. I don't tell others not to chose the sandwich.
For dinner, I like a meat, chicken, ham, lamb, beef, with a variety of vegetables, broccoli, cabbage, Brussels, peppers, mushrooms, cauliflower cheese etc. Done in a variety of different ways, no one screams I need to eat a potato becayse everyone else does.
On sat we went out for dinner. I had a steak and a salad. I asked the staff to switch the chips for the salad. No one looked appalled. The staff did not scurry away to talk about me in hushed tones.
For snacks I eat things like cheese, olives, clotted cream and berries etc.
My diet is healthy and varied, there are proven health benefits, there is nothing faddy about it because I don't shove bread and chocolate down my neck. There is no unwritten rule that I need to eat what the "vast majority" of others eat. Nor do I need to drink what they drink, I am an adult who has free will and can make my own choices.
You eat what you want, but please don't try to tell me my way of eating is faddy because there are apparent unwritten rules based on what others eat, there is no such thing.