Is it a fat fetish? iin?

I don't know how to put this, I like to watch weight pogression videos... of women gaining weight, to a point. I like to watch thin, pencil size women. Gain weight and become curvy, maybe even gain a small muffin top... that's it. I search online for this and it makes me so angry, cause I get horrendously fat women. With huge fat rolls. depending on hieght, I like women who are 180-200lbs max. from fit healthy women, to chubby ones... not fat!

I don't know what to call this fetish, and is it normal?