Pot belly is caused by that the intestines themselves are going forward. That means that pot belly is caused by the looseness of the muscles covering the intestines.
Iliopsoas is a muscle which connects the spine and the legs and is the key to lose weight. Weakness of iliopsoas gives you a bent back, causing pot belly, but if you strengthen iliopsoas, you can flatten your stomach and have good posture.
Exercise to strengthen iliopsoas
Starting posture (Fig. 1)
Sit forward in a chair and place your feet shoulder-width apart.
Straighten your back and lift your arms in front.
Movement (Fig. 2)
Hunch your back, breathing out for 5 seconds (dent your belly like looking at your navel).
Go back to the original posture, breathing in for 5 seconds.
Repeat this movement 3 times (Performing this exercise SLOWLY stimulates iliopsoas.).
Another exercise (Fig. 3)
Sit back in a chair and bend your knees at 90 degrees.
Lift up one leg slowly taking 5 seconds and put it down taking 5 seconds.
It is good to exercise 2 hours after meals because the energy of protein that is the material of the muscles can be used 2 hours after meals. If you exercise when you are hungry, the muscles can be broken down and used as energy.