Here are some prior threads on this:

Marriott Russia

Moscow hotels

Moscow locations

They are all perfectly clean and safe. But why would anyone want American food in a city bustling with numerous places to eat excellent local food (as well as just about any international cusine you can imagine), is completely beyond my comprehension... Of course, different strokes for different folks. Plenty of McD's within walking distance from any of the Marriott locations in Moscow.