"Yo probé muchas comidas diferentes."
Translation:I tried many different foods.
This may be a regional difference. I am a native English speaker. "I tried many different food" sounds very wrong. It could be "I tried a lot of food", or "I tried different food", but using "many", the only right way that sounds right to my ears is to use the plural form of food.
In American english I would say I tried a lot of different food. Foods sounds strange.
The spanish grammar is correct, but the english translation ought to be "I tried many different types of foods." English adds more filler words, but "I tried many different foods" is not the exact translation, because two adjectives should not follow one another in either language (many different). Translating word for word, it is the literal translation. A correct and proper translation could be "I tried a lot of different foods."