Question: Why does the Eshel Avraham hold that drinking coffee with milk in the morning is enough sustenance, the same as having bread for breakfast?
Background:
A. The Mishna Berura (155:2:11) says that before going to the Beis medrish one can eat bread for breakfast if that is what he is use too, and it’s good to make it a habit, as it says in the gemara: There are 83 types of sicknesses caused by bile in the gall bladder and a kibeitzah (egg measurement as per the pri megadim) of bread with salt and cup of water in the morning can prevent it. And it’s a mitzvah to act with good attributes and in good measure to protect one’s health in order to be strong so that one can serve Hashem. (Parenthetically Rav Rav Shmuel Wasner zt”l says that if one doesn’t eat breakfast properly he is not a sinner because this wasn’t enacted by the Rabbis as a mitzvah but rather only as good advice and the proper thing to do, like a queasy mitzvah.
B. The Pri Megadim says that it doesn’t have to be specifically bread but any mezonos, cakes, cookies, crackers, pizza (pas haba bikisnen) will suffice, however a cooked dish even something like pasta, oatmeal or cream of wheat would not suffice.
Answer: Since the milk in the coffee has enough vitamins and minerals in it that suffices to sustain the person for this purpose. (See Dirshu Mishna Berura footnote 8.)