Pediatrician says:

Jess • They call me mom
"Don't nurse longer than 20 minutes at a time..."
 I have a lower supply and am supplementing with 2oz of formula if she seems hungry after a feeding. I can't seem to understand why if she is nursing successfully and I'm producing at the time why I should stop her.
I asked the doctor and her reasoning was "to ensure she's given an opportunity to have enough formula for weight gain."
 Sounds to me like she wants me to give up breast feeding... Thoughts?