Human breast milk's nutritional value (serving size is 1 cup) is:

• 170 calories
• 2.5 g protein (6% of the calories)
• 10.7 g fat (57% of the calories)
• 16.9 g carbohydrates (37% of the calories)
• 34.2 mg cholesterol
• 41.6 mg sodium

• 27.7% US RDA phenylalanine and tyrosine
• 26.6% US RDA leucine
• 24.6% US RDA valine
• 22.0% US RDA lysine
• 21.9% US RDA isoleucine
• 20.5% US RDA ascorbic acid
• 19.7% US RDA vitamin A
• 19.0% US RDA tryptophan
• 18.8% US RDA linoleic acid
• 12.9% US RDA threonine
• 12.0% US RDA methionine and cystine
• 11.0% US RDA pantothenic acid
• 10.7% US RDA linolenic acid
• 9.9% US RDA calcium
• 7.4% US RDA histidine
• 7.1% US RDA folacin
• 6.8% US RDA riboflavin
• 6.4% US RDA copper
• 6.3% US RDA potassium
• 5.5% US RDA vitamin B12
• 4.2% US RDA phosphorus
• 3.5% US RDA zinc
• 3.1% US RDA thiamin
• 3.0% US RDA magnesium
• 2.9% US RDA niacin
• 1.8% US RDA manganese
• 1.7% US RDA vitamin B6
• 0.5% US RDA iron

So not only is the delivery system quite excellent, but the payload is very healthy too!

Source:
    USDA website