Black Labs eating habbit

Question
How much should a 3 year old Black Lab eat
and how much should they weigh.

Answer
Nobody can tell you that without examining the dog and knowing what you are feeding.  I can give you a link to learn how to examine the dog yourself.  It is a Purina site, but the method is the same as the dog guide school uses on their highly valuable dogs,  http://www.longliveyourdog.com/twoplus/RateYourDog.aspx  You may ask your vet to confirm your judgment the next time you are in.  If your Lab is the typical overweight Lab, just cut back until it starts losing weight and then find the level to maintain ideal body condition.  You dog may be disappointed in how little you are feeding him.  My adult Labs get about 3-4 cups of Pro Plan a day.