High Quality Content by WIKIPEDIA articles! Sagittal Abdominal Diameter (SAD) is a measure of visceral obesity, the amount of fat in the gut region. SAD is the distance from the small of the back to the upper abdomen at the point midway between the top of the pelvis and the bottom of the ribs, measured while standing. SAD is a strong predictor of coronary disease, with higher values indicating increased risk independent of BMI.