Yes you will still go into ketosis as you are on very low calories.
Anything under 800 calories is called a very low calorie diet.
The same principles apply to the 790 as when SSing and you must introduce carbs gradually when you finish the plan so that you do not carb overload.
The weight loss is very similar to SSing perhaps a pound or two in some people... it is just that some people may need a total break away from food to help them overcome their over eating.
Love Mini xxx