My best gf is doing the low carb thing which I am normally against but for people with insulin resistance it's hugely helpful. She is doing it to control her insulin resistance but an unfortunate side effect is wt loss. Also if you have a gluten or other intolerance you won't lose.

Most people also need a lot more than 1100 cal a day.

And, last bit of unsolicited advice, there is the possibility that your body is doing fine. You are active and I assume eating well and for a good number of people that does not always translate into thin or wt loss. It's possible to be very healthy and medically overwt.