A.Z. Central explains that how long it will take a person to achieve flat abs depends on the fat content in his body. First, a person needs to use a body mass index (BMI) calculator to determine the amount of fat he has in his body.Continue Reading
One pound of fat is 3,500 calories, so lowering caloric intake by 500 calories a day loses 1 pound each week towards flattening the stomach.
According to Registered Nurse Diane Marks for A.Z. Central, the Centers for Disease Control and Prevention reports that if a person's BMI is over 24.9, that person is overweight.
Once a goal weight is established, the length of time that it will take to achieve that goal can be determined. If an individual has a goal of 140 and he weighs 160, it should take him approximately 20 weeks to lose the fat.Learn more about Fitness & Exercise