Thanks for your question, but unfortunately the answer is that this varies widely from patient to patient. If you are overweight, your tummy may not be as flat after a tummy tuck, but your weight loss from the surgery will be larger. Likewise, if your only problem is loose skin, your change in weight and abdominal circumference will be limited. I would say that with my patients having a tummy tuck, the amount of tissue removed weighs anywhere from less than 1 lb (less than 1/2 kg) to 10 lbs (a little under 5 kg). I usually never measure abdominal circumference. Hope this helps, but an exam with a plastic surgeon will better answer your question. Best of luck!