How long it will take depends on your metabolism. If you’re really fat, you’ll lose fat quickly if you follow a good meal plan and any form of exercise will just add to it.
All you have to know is if you burn more calories than you consume, you’ll lose weight. It might not be apparent really soon as our bodies have the habit of storing water, which results in water weight. You can lose fat just by controlling you calorie intake, any form of exercise just facilitates it. You’ll definitely see improvements by 3 weeks. If you follow a really good meal plan and workout strictly, you might see results in a week.
There’s no diet or exercise programme that can reduce the tummy fat or any other specific body part fat.
Once your body is calorie deficient, your body starts to burn the stored fat for energy. But Here comes the problem, from which part of your bodyfat has to burn first ???? Generally speaking it takes fat from overall body and you start to lose weight.
If you do abdominal or any other specific body part concentrated exercise, the muscles in that body parts will strengthen. But you don’t expect to burn the fat from exercising body part faster than other areas. What happens is for ex: If you’re vigoursely do abdominal exercise, Your abdominal muscles groupes will strengthen with the fat layer still on outside that yet has to burn later.
So the answer for question is there’s no such thing as spot reduction. You’re body will start to consume fat from all adipose tissues( fat cells) and once your fat storage has depleted, your body will in a good shape and of course your abs too.