I think Samson was about 10 weeks old when I took him for his 2nd shot and I wasn't sure about the feeding so I asked the vet and he said he should be eating around 150 calories a day. Which with his dog food was I think about a half cup a day, I may be a little off. That's pretty much what I fed him and some days he would eat all of it and others he wouldn't but he's overall not one that will eat everything that's put down for him so I was able to just leave his food down all the time and he ate when he wanted. I've read both opinions about only feeding at certain times of the day and others that say let them eat whenever they want. My experience has been that it worked to let him eat whenever and he is now 7 months and his weight is fine.