I would strongly recommend that you schedule an appointment to talk about this with your doctor
and to possibly get set up with a nutritionist
going forward to make sure you are doing this in a healthy way.
As a brief overview, calorie restriction is the scientific theory that eating the bare minimum of calories needed to survive reconfigures cellular signaling pathways to make them anti-inflammatory and pro-longevity by maintaining a kind of perpetual activated survival state. Calorie restriction has been shown to extend lives in animals, but has not ever been shown to improve longevity in humans. The closest studies that have been done have been in monkeys, and have shown mixed results; the most recent such study did not find a longevity benefit, and while there was less cardiovascular disease there was also more infection, impaired wound healing, and a decreased fertility. Particularly if you are a young woman I would strongly advise against losing enough weight to prevent you from having a normal menstrual cycle, since this is essential to your long-term bone health. All of which is to say that, while some scientists are still practicing calorie restriction, right now the potential benefits of this diet are unknown in humans, and there may be harms as well. Particularly if you are exercising regularly you are right that you will have higher caloric needs that may not be met on a calorie restricted diet. I think it is great that you are interested in eating in a way that is good for you, and I think your primary care physician
and a nutritionist can help you determine what is the best approach for you.