Limiting calories can potentially be detrimental to your health. When reducing calories, it’s important to go for highly nutritious and high fiber foods (your microbiome needs to be eat too.) Load up on a LOT of various vegetables, especially greens (may even help your asthma by supporting your nervous system health) and maybe even add in some vitamins and mineral supplements to help boost anything you're losing by reducing calories. I admire you taking charge of your health. Good luck. <3