Let's see what the native speakers say. ;)
I'd say suggestion and recommendation is rather similar. However, suggest/recommend and suggestion/recommendation goes from less to more formal. E.g. conclusions at the end of a report would contain recommendations, never suggestions. "Can I suggest you put on something warmer, it's really cold outside" "They [weather forecast] recommend you staying indoors due to an approaching storm"
Food is what you eat and meal is during which you eat it. "I had way too much food at my last meal" - meal can be lunch, dinner..meal is a specific moment in time during which you eat.