24 Hrs Stopover

You could do the Big Bus Tour. That will allow you to see most of Dubai's sights within your limited timeframe.

In terms of food: Since you will be traveling, it will not obligatory for you to fast, even though it's Ramadan. However most of the restaurants, food courts, etc. will be closed during the day. And even if you get something from a supermarket or from one of the take-away restaurants that open around midday, you should not eat in public. After Iftar you can of course eat and drink wherever you want.