Weight and Sleep

As previously mentioned, Silas was born weighing in at 3932 grams. However, on the day we were discharged from the hospital, he weighed 3770 grams. Yesterday (Wednesday), the community nurse came by to check up on him, and at the same time, to weigh him. He weighed only 3642 grams. We became a bit concerned about his lack of weight gain, because after about 2 or 3 days of birth, babies are supposed to start gaining weight again, and not continue to lose weight. The nurse suggested to supplement his breastfeeding sessions with an extra ounce of baby formula.
That seemed to have worked. This evening, we went to a drop-in clinic and had him weighed, while my wife inquired about tips for breastfeeding. Silas weighed 3724 grams, which meant that he gained almost 3oz in 24 hours ! What a trooper.

I don't think there's really any problem with his weight, it's more a matter of getting the breastfeeding administered to him properly. He is a bit of a fussy eater.

He is now eating on a strict schedule of every 3 hours, starting at 12am. I think he's been awake for only about half an hour in between each feeding, which means that he's been sleeping about 18-20hrs per day. How can you lose weight when you're sleeping that much ?