I ate fairly well just as you have been doing & put on around 25kg with my second pregnancy! It was scary when I looked at the scales but to look at me there was no excess weight anywhere except for in my belly! I think some people are prone to put on more when they are pregnant. Don't forget also you have baby, placenta, amniotic fluid, double the normal amunt of blood plus any fluid you're retaining so that all counts for quite a bit too