I Have Had Some Bad Relationships

I was dating this a-hole at college. I am not skinny but isn't overweight. But this guy have preference for skinny girls. Even at college, I aspired to be a web developer because I like coding and computers which meant sitting at desk for long hours and likely to gain weight. This a-hole keeps telling me I should look for a job that allows me to move around more because my body is susceptible to gain weight. This leaves the question why did he asked me, a not skinny girl, out if he likes skinny girls? I like to have a healthy weight and a bit of curves on my body. I don't want to starve myself to be one of those stick figures. Of course, the relationship didn't last more than a month because I caught him cheating with a skinny girl.

Edit: I do have a desk job but takes time to take care of my body by daily exercises and diet.