Grayson is seven months old and over 60 pounds. I was feeding him at set times--to help with the house breaking thing. And I didn't want him to overeat and make himself sick. Lately, he'll take a few bites and walk away. Come back a little later. For the most part he is housebroken--an accident here and there. And I don't mind letting food sit out--since my yorkie is a grazer anyways it would be easier. But I am also worried he has cut down how much he is eating. I was using the directions on back as a loose guide for amounts and he was eating it all up, now though he is letting food sit.
I don't think grazing is necessarily a bad thing in itself unless you just keep the food dish full - hence over-feeding. Often the suggested serving amount on the bag is too much. If Grayson is not overweight then I would feed the amount you think he needs, weigh him in a month and see if he has gained or lost and change his portion accordingly.
Monty is 15 months old, 60 pounds. I leave his food dish full all day. He has never emptied it, eats a little, walks away, comes back later. He eats less than he did as a puppy, although I have to say he gets more extras, sometimes extra treats, but he is truly fond of carrots, watermelon, apples, strawberries, bananas. He seems to be perfect weight. I dont think you should worry as long as his weight is where it should be.
There can be long term problems when leaving the dish full without actually paying attention to the amount you are feeding. When they are young they may not overeat, but as they age and get less active, they are still grazing and you are still filling the bowl and they end up eating too much. We had a wonderful Springer that we free-fed for her entire life. She was never a gobbler or big eater. But we wondered why she was fat when she got old - it never ever dawned on us that we needed to put less in that bowl so she wouldn't be fat. We leave Ned's food down (hoping the others don't eat it) but we pay attention to how much he is actually given in that bowl. The overweight creeps up on them, especially if they are fluffy-coated.
Darwin eats his food all at once. When he was about 8 months old, he started grazing so we reduced his feeding times from 3 times a day down to 2. Now he is back to his normal eating habits.
Same with my two guys. They get two meals a day, and they eat them all at once. If there is anything left in the dish it gets thrown away (but that is rare). This may have to do with the fact that I have two dogs....they eat everything pretty quickly because they don't want the other one to get it.
Murphy grazes. I put all of his food in the bowl in the morning. When I come home from work, most of the food is still there. He finishes it off sometime before bedtime.
Harley is this way too....she usually doesn't eat her food until later in the day (after she figures out she isn't getting any people food....too funny.)
Set eating times vs grazing is totally up to you. It really depends upon your preferences and what you think is best for your dog. A meal that might spoil vs kibble are other considerations.