Hi. I’m not vegetarian, but find vegetarian dishes very satisfying for a fast day. All types of beans, lentils, and tofu, are high in protein. Also eggs and cheese, but cheese also usually high in fat. I make lots of different types of soup with chick peas, lentils or beans, usually adding veg such as onions, celery, cabbage or tinned tomatoes, which are very low in calories. You can flavour with herbs, lemon juice, piquant sauces, or coconut, for example. I find googling the ingredient very helpful for estimating calories. A nice cookery book is: 5:2 Vegetarian by Celia Brooks. Good luck. I’ve been doing this for almost 4 months now, and have lost 6 and a half kilos.

textured vegetable protein (tvp) has 50% protein and little else. I cooked it in a tomato sauce and ate with veggies. Very easy, ok taste and very low cal.