Overweight toddlers

We are a fit family and no-one is really struggling with their weight; apart from out daughter.

When she was 12 months old She already weight 12 kilos which is way to much.

She is now 2 years and still a bit to heavy. Obviously we cannot put her on a diet.

She never had sugar, we don't give her chocolate or ice cream. We don't watch television and spend a lot of time outside.

I had to bottle feed her as she was struggling to gain weight after birth. The doc always told me baby knows when she had enough. Die to a condition I didn't provide enough breast milk.

I am worried. Every time we go to the doctor she gets weight and mothers talk about their kids weight.

Any advise?