Are you sure obama pays for all of his food? So when obama hosts people , like say an ambassador from Germany, or perhaps a business leader, you think obama pays for the meal? That perhaps that money doesn't come from the yearly white house budget?
I don;t think his $400,000 salary could handle all of that. Perhaps the food obama pays for (including toothpaste and dry cleaning) is for family meals.
You should not be so quick to tell other people to shut up.... you might actually learn something about how the world works.
No, when its a United States function the government pays for the food. Having a personal guest like Romney is paid for by Obama.
Nancy Reagan famously complained at the prices the government charged them for food.
"Fortunately" Presidents can use campaign donations to pay for their expenses in office so in the end the Obamas won't pay anything out of pocket.
As to what exactly determines if a function is personal or governmental related you will have to take it up with the lawyers. However, if the government pays for the food then it is a governmental function and gets covered by things like the Freedom of Information act. In many ways its very similiar to what you can write off as a business expense in the private sector.
And this is common knowledge so anyone who doesn't have even common knowledge of our government should stfu and stop posting nonsense.