hi there. i have to disagree w the last reply. although i respect the choices people make for their households its not the best one in my opinion. never leave food out all day! it could get contaminated first of all. you should give am and pm feeding dogs can get hypoglycemic so its good to give a little in am and pm with healthy treats hear and there like carrots, apples, cottage cheese helps puppies in brain development. when you give all day they have no poop schedual and no respect for you. in the wild dogs did not eat all day they ate when they found prey sometime days( fasting was common and helped w the removal of intestine parasites). free feeding can lead to boredum in the food world. they become finaky and dont follow you as a leader cause food is always there why should they look to you? as far as the amount you can judge it by what the bag says but remember the pet food co wants to sell food they sorda recomend a little tooo much! if you judge it by when the dog stops eating they could still be getting to much food dogs eat for nutrient content not to fill their stomach so make sure it is a well balanced food ment for your dogs particular needs! and like i said add other things like fresh chicken look up dr wheils on natural diets his book it might be helpfull to you.