Not necessarily though. You lose weight if you have less calories than you burn. You can be in ketosis, but if you stuff yourself silly with high calories, low carb/carbless stuff, you wont lose weight.
But...people in ketosis rarely want to stuff themselves with the above. That's the beauty of ketosis. You can reduce calories so much easier
That is true. Ketosis is the name for burning fat for energy. There is no distinction between dietary fat and body fat. Ketostix also will not show the difference. It is actually possible to be in ketosis and put on weight.. I saw an example on another forum once of a woman who could not understand why she wasnt losing weight, when she put what she was eating each day it transpired she was having a massive amount of fat.. over a 1lb of butter alone.
Ketosis supresses hunger, so people rarely overeat, most lose weight. It is still important though to make realistic and sensible food choices.