I think it took about 4 months for me. I gained 16kg during pregnancy which was huge for me bc I'm only small. My belly took ages to go down. I did absolutely no exercise, lol, and my diet wasn't that crash hot either. I think it was just breastfeeding a hungry baby. Now I am down to 47kg which is 6kg less than before I was pregnant. I don't ever remember being this light, even in high school and the only thing I'm doing different is breastfeeding so I think that just really works for me. But my tummy isn't flat at all, it never was but it's more podgy now, lol.