Milk contains lactose, fat and protein. And like other dairy and animal products, it is an acid-forming food. Take it on empty stomach may worsen reflux symptoms or cause mild diarrhea in some people. The best way is to drink it together with snacks, bread and food containing carbohydrates. Lukewarm milk is easy to be digested than cold milk. It is a good source of calcium for building stronger bones and teeth. The iron, copper and lecithin in milk improve brain health, too. However, too much milk may be harmful to the body, or even result low bone mass according to some research.