Confusion between Pedi and breastfeeding norms. Help please!!

cal031686

My DD is 2.5 weeks old. She was born 4 weeks premature and lost quite a bit of weight when she was born. In the hospital I was letting her eat to her content on each breast roughly 12-15 per side. She didn't gain very much and the pediatrician said to limit her to 7-8 minutes per side and then give her another round if she wanted. The pedi's reasoning was that she is getting most of the milk in the first 7-8 minutes. So I breastfed her 7-8 on each side twice. We went in for a week checkup after discharge. She had only gained an ounce. The pedi again said that she doesn't need to waste energy nursing more that 7-8 minutes on each side. My confusion is that all the breastfeeding information says to completely empty one breast before offering the second. I will also note that DD bowl movements have been a dark greenish color, which I have read is not normal. They should be yellowish correct? So what do I do? I want baby girl to breastfeed and she does amazing at it. But what information do I follow to make sure DD is eating the correct ratio of hindmilk/ formilk? Please help ladies. TIA