This thread is really concerning. Proper nutrition really needs to be taught in schools. 800-calorie diets should only be undertaken under medical supervision and for no longer than 2 weeks. It can quite literally kill you.
The last time I needed medical treatment due to restrictions I was eating 600-800 calories a day. I thought what I was eating was okay and it was certainly more nutritionally dense than the diet OP was on. Admittedly it was very "samey". Eating disorders are about control. Like OP could eat her pre-packed foods I could only eat my "safe" foods and had a set of very strict rules I needed to follow, which even at the time I was following them I knew were nonsensical but I needed that control to keep me sane.
For breakfast, I would have 30g of porridge oats (114 cals) with 125 ml skimmed milk (43 cals), half a banana (50 cals), and a teaspoon of peanut butter for protein (40 cals)
Lunch a small bowl of salad made of lettuce, cucumber, cherry tomatoes, a tiny helping of beetroot, onion, 6 ocean sticks and a splash of Hellmann's 3 calorie salad dressing for 170 calories.
Dinner was an omelet made with 2 medium eggs, onions, and mushrooms and served with a handful of fresh spinach for (200 cals)
I rarely deviated from this but did swap out some meals for berries and Skyr, jacket potato with tuna and sweetcorn, and grilled chicken and veg.
After 3 months I suffered abnormal heart rhythm due to critically low potassium levels and was diagnosed with EDNOS and referred to a nutritionist who made it very, very clear that no matter how carefully planned your diet is, your body cannot sustain itself on 800 calories. There simply is not enough volume to get all the micro and macronutrients you need in 800 calories. Your brain alone uses 500 calories a day.
People who follow an 800-calorie diet for medical reasons do so under strict medical supervision and with prescription supplements and only ever for very short periods. 1200 calories a day is the bare minimum and even that is pushing it and should only ever be followed for short periods.
Seriously, some of the "advice" on this thread is dangerous and is definitely encouraging disordered eating. If you need to lose weight and think this is a good way of doing it please see your GP first and tell them what you plan on doing and ask to be referred to a nutritionist.