As mentioned above, we live here and we eat too...granted, you may have a couple of stomach upsets when you visit some restaurants, especially street hawkers that sell fried pork, but this is mainly to do with the cooking oils they use, not the actual food. A lot of restaurants do not change their oils on a regular basis. Dominicn fast food is char grilled chicken that is sold on the side of the roads...this will most likely be the best chicken you have ever eaten in your life. Do not be afraid of trying this...most places sell it with a combination of rice, (go figure!), fried platano, yucca and salad. It is very cheap and better than ANY chicken you would eat in a restaurant. If you are here around Christmas time then you can also experience the best pork roasts...this meat is so succulent and tender it is making me hungry just writing about it. If you drive from Puerto Plata to Santiago over the Christmas period then you will drive past hundreds and hundreds of pigs being roasted on the side of the road...definitely not a good time of the year to be a pig!!
If you get sick at home, well, that will most likely be down to your cooking...lol.
All jokes aside, the food is fine here. The meats are excellent but as Sanation mentioned, the beef is too young. When I buy beef here it is mainly for stews. The best meats available are in the German butchers in Sosua...you will never purchase bad meat there, but they are quite pricey..
I purchase nearly all my vegetables off the back of the pick up trucks. They are the cheapest, best and freshest vegetables around. For 100 pesos you can almost fill up a shopping bag of veggies! I have never purchased anything special to sanitize my vegetables, I just rince them with tap water. If I eat raw vegetables then yes, I will rince them in bottled water.
During the rain season I would take more care as the run off water from the mountains is very dirty. I brush my teeth everyday with tap water, but after heavy rains then I will switch to bottled water just in case. Bottled water is dirt cheap, only 35 pesos (one dollar) for 5 gallons so even if you wanted to boil your rice it is very affordable.