Hi J, we're doing it too (husband and I) but only recently restarted after a gap of a few years. I'm vegetarian and on fast days tend to skip breakfast, have a low calorie soup or salad for lunch and then something a bit more substantial in the evening etc. G. veggie stew. I tend to have tangerine as a snack to keep me going. Husband is not vegetarian so tends to have cauli rice and meat of some kind for lunch. I definitely find it easier to use recipes so that the calories have all been worked out rather than having to do it myself.
Happy to share recipes but I'm mainly doing a few by Celia Brooks and Elly Curshen at the moment.
Hannah