I didn't realise I was doing anything like fasting until I saw people talking about it on here. Like you, I tend to get up late - usually between 10am and noon. And bedtime is nominally 1am but can be much later if I've got my nose stuck in a book. As the evening meal, anywhere between 7pm and 11pm, is the last thing I eat in a day, that means I'm technically fasting between twelve and sixteen hours each day. It works for me because I can quite easily go to sleep when I'm moderately hungry, and the evening meal contains plenty of protein which stops me feeling hungry in the evening.
How are you managing the lunch/breakfast thing at the moment? Lunch foods for breakfast, or breakfasty foods then a much later lunch? And if you're going to bed late, does that mean you're eating late? I'm curious to see how other people who keep odd hours manage it.
As for other sources of protein, this is copied and pasted from wikipedia:
"Examples of vegetarian foods with protein concentration greater than 7 percent include: soybean, lentil, kidney bean, white bean, mung bean, chickpea, cowpea, lima bean, pigeon pea, lupine, wing bean, almonds, Brazil nuts, cashew, pecan, walnuts, cotton seed, pumpkin seed, sesame seed, sunflower seed".
So nuts and seeds, peas and beans. Eggs are also good. Just don't go mad with them - some of those nuts are pretty calorie dense and it's easy to eat too many of them. There's also red meat - would make a change from chicken and fish, and if you're eating it in moderate quantities and cutting the fat off then it should be fine.
Fasting and Protein?
I already eat a lot of fish and chicken, but I'm not into eating that every day. Thank you! 
