how much should i feed her

Question
i have a 9 month old choco lab...i currently feed her one cup of food twice fight now it is half and half puppy/dog food... but i take her to the dog park and she looks so much smaller then the rest of the labs... she is about 40-45 lbs now and to me she looks fine till i compare her two the others and some of them are very fat. i just want her to be healthy lean weight but i don't know much about labs... can you send me a chart or something that shows different ages and what amount they should be feed at those ages...

Answer
The charts exist, but aren't much use.  Each dog is different.  I can give you a link to determining how much your dog should weigh, http://www.longliveyourdog.com/twoplus/RateYourDog.aspx  You then adjust the food and exercise to reach the ideal condition for your dog.  

Unfortunately too many Labs are over fed.  I am pleased you are concerned about your dog.  

There was an extensive discussion of weight in a recent newsletter from a service dog school.

''Obesity is the number one nutritional disease affecting dogs. It's estimated that 25-45% of dogs in the US are obese. Studies have shown that joint and locomotive problems increase by 57%, circulatory problems by 74%, respiratory problems by 52%, skin problems by 40% and cancer by 50% in animals that are overweight.

Large breed dogs that are overweight also are more prone to developing hip dysplasia. Obesity is especially dangerous for young puppies, as their underdeveloped frame cannot support the extra poundage that it must carry.''