Coffee and milk can be applied, there is no mutual reaction between the two substances, the main component is water. In addition, milk also contains some protein, fat, coffee contains some carbohydrates, crude fiber and other components. Two cups of milk and coffee a day are usually enough, and should not be used in excess. If excessive application is also easy to stimulate the nerves, leading to the emergence of nerve excitation, so easy to cause the symptoms of sleepless nights, at the same time, if the milk application is too much, it is also easy to lead to the occurrence of body fat and other situations.