4. Widespread use of preservatives in order to prolong shelf life of food.
5. The compliance capacity of many restaurants toward health department regulations is slim, barely making minimums.
7. You usually don't know where your food comes from.
8. Kitchens and preparation surfaces are often cleaned with harsh chemicals before your food is prepared there.
9. You have about a 50/50 shot at the fish you ordered actually being what it is stated as in the menu (based on lab results from restaurants in 24 U. S. cities). More expensive fish is substituted with cheaper alternatives to maximize profits.
10. Restaurants mark up all meals to average the profits at about 60% and although a lot of it goes for expenses, do you really want to pay a 30 - 40% markup on the meal you could have prepared yourself?