YouTube search Dr Berg's video: How To Fix A Slow Metabolism.
Thanks that helps. I am pretty sure the diet caused the anaemia and other problems, so I am thinking that will go now. The palpitations certainly seem to be gone already. I don't know if there was any permanent damage, I assume not but I was curious. I am eating a lot more now and I am going to start doing a bit more exercise to my routine to hopefully keep the weight off. It confused me because even at 900-1000kcal a day, I was only losing weight gradually. So I am worried that at around 1500 I am eating now, the weight will go up rather than down. But I am going to try to switch in more protein and do a bit more exercise.
My doctor only diagnosed problems after I had already been dieting for 18 months so the damage was already done :( I am just eating normally now. It is not supposed to be a high calorie diet, I just googled how much a person is supposed to eat and there is a calculation you can do based on height, weight, age, sex, and physical activity. Mine came out at about 2000 which seems normal from reading online. But I have been on 900-1000kcal for so long, 2000 is a huge increase and I am worried about getting fat and also don't know how long I should do this or if it is even necessary. The calorie information online is scientific, but there is no good info about how to get a stable metabolism and what you should do if you put weight eating less than the recommended daily allowance. That's why I'm asking here. I saw bodybuilding websites where people talked about the same thing, someone was putting weight on by only eating 1500kcal a day and people said it sounded like a medical issue, like thyroid etc. I can ask my doctor to help with this but it might take 2 more weeks and he might not even know and may refer me to someone else. In the meantime I am putting weight on each day.
You say you saw a doctor who diagnosed you with a problem. Then, if I have this correct, you went to a random site online and started a high calorie diet? I'm confused -- do you have a medical problem or a medical problem induced by your extreme dieting? If the latter, why are you going on another extreme diet? Dieting doesn't really work --- changing your permanent diet and your energy output does. It might go more slowly but it will get you where you want to be all the time, not just for a month or two. But given you've seen a doctor and have a problem, I'm wondering if you asked your doc what to do? And since docs don't know a whole lot about nutrition, were you sent to a nutritionist to get you to a healthy way of eating? (I would look for the ones who call themselves holistic nutritionists, as mainstream ones don't really push healthy food and that's important).