Warning!
Always try to aim for the "Fat Loss" daily calorie level.
The "Extreme Fat Loss" level is effectively a rock bottom calorie level. Do not attempt to immediately drop your calories to this level hoping for the quick fix. This may ultimately backfire.
The Extreme Fat Loss level shows the lowest calorie amount that can be considered. It should be seen as the exception rather than the rule.
It truly is better to burn the fat than to starve it.