Calory Defecit

I (m23) am 5'10" around 72kg.My ex told me she doesn't think I eat enough so I started tracking my calories.I average about 850 calories intake through food (intermittent fasting with two meals, one at 12, one at 6), and exercise with a walking treadmill while I work (about 500 calories a day) and do two 2 hours gym sessions a week with a 30 minute weight circuit every morning.The only goal I have is to tone up a little and have my abs more visible by the summer but when I look online there is a lot of fear mongering around the negative side effects of being in a serious calory defecit.These have been my habits for a few years (I couldn't tell you my exact calories but I haven't made any changes this month) and I have never noticed any of these negative side effects. Should I be concerned? Why? Am I going about my goals the right way? Looking for information/advice from more experienced folks!TLDR: in serious calory defecit, no side effects, should this worry me? via /r/intermittentfasting https://ift.tt/JX5WpyM https://ift.tt/0VKXnB4