I went from 180lbs to 160lbs?

Hmm...did you lose 20 lbs rapidly? The reason I ask that is because I think by the sounds of it, your body is in starvation mode. The bare minimum of calories that a man can eat daily is 1500. You said you have been having no more than 700 daily. Therefore your body doesn't know when it's going to get food again and it starts holding on to everything you eat and converts it to fat. You should increase your calories to speed up your metabolism.