I understand that some women like to gain weight on purpose.

How can I find one. Has anyone ever met a woman gaining weight on purpose?

Why not just find a women that is at the weight you are happy with?
Like if you want a 200 pound woman then look for a 200 pound woman.

The body seeks a certain weight. If someone is gaining it on purpose, they could probably lose it easily just like people who diet to lose weight, tend to gain it back.

To find heavier women, go to a place where they pretty much need to get in a car to get anywhere. In a city, where you can walk to shop and work women tend to be smaller.