The number of fat cells you have remains fairly constant throughout your life, regardless of whether or not you diet, or are thin or fat, say researchers at the Karolinska Institute, Sweden. In a study published in Nature they have demonstrated that we continually create new fat cells to replace those that are breaking down. The scientists have also demonstrated that fat people do this at a faster rate than lean people - obese people’s fat cells die at a faster rate and are created at an equally faster rate.
It seems that you are stuck with the amount of fat cells you had when you were twenty.
That leads me to the conclusion that if you were not an obese child, you should not be worse off, after having dieted down, than someone who always was lean.
However, a lot of FFB feel that they gain weight way faster than the average person. Why is that, when they theoretically should be just the same, since more fat cells can not be the issue, unless they were always obese?
PS: The good news is that they are working on a drug to prevent new fat cells from forming, so if the old ones die and new ones are not built even the fat cells acquired in childhood could be eliminated.