Hi pp23,
I think you're right that a lot of this is trial and error, as everybody is different. Like you I also eat a lot of spaghetti (preferably with more fried/boiled/roast vegetables than pasta) and also some olives or chilli for flavour. Agree it's SO boring otherwise. I try to incorporate lettuce, cucumber or some form of side salad with most things.
My personal approach was to download the USDA database choline content of common foods spreadsheet, strike anything off the list that I knew was high in soy lecithin or torula yeast, and make my own recipes from the lowest choline foods on there. Being able to cook helps. How are you with making things from scratch? I also make a lot of smoothies in summer and soups (with minimal stock cubes and no onion/garlic) in winter.
Don't know if this helps, but I've been meaning to share a few products on here that have totally revolutionised my life. Hopefully they will be of use to somebody.
*Two chicks egg white (v low choline source of protein. Way better than poultry, which I would never eat).
http://www.twochicks.co.uk/stores/.
*Whole pieces of fresh coconut, available from Tesco, Waitrose etc etc. Often nearly 400kcal in just one pot. Excellent source of calories and fibre. (I am basically maintaining a healthy BMI of 19 because of these, whereas previously it was dropping a bit.)
*Any rice vermicelli made with 100% rice (check there's no rapeseed oil in the ingredients). It's usually easier to find these at small independent supermarkets that cater to Eastern European, Indian etc customers. You can put them in vegetable stir fries with lime, chilli etc for flavouring. This one may depend on your personal reaction to rice.
*Tinned pears for days when I'm really rushed off my feet and just need some extra calories without having to cook. Fresh is better, but I'm busy & live in the **** end of nowhere, so sometimes they're my only choice.
*I also find that keeping hydrated with isotonic drinks works for me personally (though I'm unaware of any medical research that supports the use of isotonic drinks in TMAU). PowerAde zero and coconut water could be considered an 'interesting' drink by some!
Good luck!
Tx