newbie, post-ketones, 3u N BID on Health

Can anyone offer some knowledgable advice? I've not used N, nor have I ever had a cat prone to ketones, so I'm really not sure how to balance the steep drop of N against the need to prevent ketones. This is the cat's first day at home; his bean is going to pick up ketostix and home testing supplies tomorrow. Thanks for any help; the thread is here.