1 KG = 2.2 bls do the math!
Who is "they"? Your question needs to include their name(s).
Oddly not too much (at first anyway). Your body goes into starvation mode and conserves energy anyway that it can. When you do eat again, the body will pack most of that away as fat because it...
exactly 61.8%
On Google search body mass index, all the answers are there. Trust me that's how I found out I was overweight