What's the minimum amount of calories you need to eat daily to survive?

I'm a vegetarian and I want to do a 5 day fast so I can reset my gut. I have very bad digestion for the past 2 months, and I think it's because I gobble down my food in 5 minutes. <br><br>I have a few questions about fasting, and whether I'm doing it right. I haven't eaten anything for the past 48 hours now except water, tea, coffee and black salt. I have to fast for 3 more days. <br><br>Is it alright to drink tea and black salt? Most of the videos I've watched say you can drink tea. <br><br>Also, are there calories in tea? I was thinking that tea has calories but then I looked at the calories of black tea, and it's 0 calories. I've literally been drinking litres of tea and black salt water everyday with 0 calories. I've eaten absolutely nothing in the past 48 hours. And I'm just drinking water and tea, so am I surviving on literally 0 calories? <br><br>If you can't survive on 0 calories, then how many calories is the absolute minimum calories that you need to survive daily? <br><br>And another thing, I've heard that if you're too skinny, then you can't do a water fast because your body will start eating away your organs. So does this mean that if you're too skinny, it's better to do a calorie deficit diet instead? <br><br>I think I'm kind of skinny. My BMI is 20, and my height is 165 cms, and my weight is 56 kgs. I just want to know if I'm skinny enough to be too scary to do a water fast? <br><br>I don't feel weak or anything after 48 hours of fasting but I feel slightly dizzy. I'm drinking tons of water. I was thinking that my body would start eating away my organs after 2 days of a water fast if I'm too skinny, but I've already survived 2 days so far, so I guess my body hasn't started eating away my organs yet. <br><br>I'm still paranoid though. I want to know if I'm skinny enough to be too crazy to do a water fast.<br><br>And also, how do I break a fast? Do I just eat anything? I'm planning on eating something light like soup or a salad, or maybe fruit. But how many calories should I eat everyday after I break my fast? Should I eat a calorie deficit? Or should I just eat normally?<br><br>Please let me know because I'm getting very paranoid about this and I think I'm making a mistake.