http://www.keto.org/foods.htm
Ketogenic Foods
Here's a partial list of just some of the foods that can be consumed on a ketogenic diet. I'll start with the '100% safe foods', the ones that shouldn't throw you out of ketosis due to having either no carbs, or trace amounts of carbs. Next I'll go to 'questionable' foods, such as hotdogs, where you must check the carb content on the package, because some hotdogs have only 1 gram of carbs per hotdog, some have seven. I'm also including a list of higher carb content foods, that can be eaten in VERY limited quantities. Finally I give a list of foods that shouldn't be eaten on a ketodiet at all. (Note: I've tried to list every food I know, in any form, so there will be some redundancy. Foods marked with an '*' are considered healthy, we highly recommend eating them as much as possible while staying under your carb limit and staying in ketosis!)
Safe Foods (No Carbs/Trace Carbs)
Beef, Steak, Hamburger, Prime Rib, Filet Mignon, Roast Beef, Chicken*, Duck, Any Fish*, Tuna*, Salmon*, Trout*, Halibut*, Lamb, Pork, Bacon, Ham, Eggs, Shrimp, Crab, Lobster, Butter, Oils (Olive Oil*, Flaxseed oil*, etc.), Mustard, Salt, Pepper, Soy Sauce, Tea, Coffee, Heavy Cream and Nutrasweet/Equal.
Minimal Carb Foods (Limited Quantities Only, Check Carb Content!)
Broccoli*, Spinach*, Lettuce*, Cabbage*, Bok Choy*, Kale*, Asparagus*, Mustard Greens*, Mushrooms*, Cucumbers*, Pickles*, Olives*, Celery*, Green Beans*, Brussel Sprouts*, Cauliflower*, Artichokes*, Peppers* (Red, Green, Jalapeno, Habanero), Onions*, Nuts, Flaxseeds*, Cheeses, Salami, Pastrami, Hot Dogs, Sausages, Ribs (watch out for the sauce!), Buffalo Wings, Liverwurst, Oysters, Abalone, Protein Powders, Sugar Free Jello, Salad Dressings (some), some Wines.
Higher Carb Foods (Very Limited Quantities!)
Grapefruit*, Lemons*, Limes*, Strawberries*, Olives*, Rasberries*, Blackberries*, Kiwis*, and Half-N-Half.
Foods that are NOT appropriate.
Beer, Mixed drinks, Bread, Milk, Pasta, Grains, Cereal, Rice, Potatoes, Corn, Carrots, Peas, Candy, Cake, Cheesecake, Donuts, Fruit Juices, High Carb Fruits (Apricots, Banannas, Peaches, Nectarines, etc.), Pastries, Non-Diet Soft Drinks, Rolls, Bagels, Popcorn, Battered Foods (Fried Chicken, etc.), Gravy, Honey, Sugar, and Corn Syrup.
Notes: Diet Soft Drinks, such as Diet Coke, Diet 7-Up, and Diet Pepsi can usually be consumed in large quantities, but the citric acid content in these drinks can throw some people out of ketosis. Be sure to check in your individual case if this happens. Hard liquor, such as scotch, vodka, etc can be consumed because they have virtually no carbs. Wine actually makes a nice ketogenic alcoholic drink, as most wines have only 1-6 grams of carbs per glass, the sweeter the wine, the more carbs. Beer is usually very high in carbs, having 10-15 grams per glass. Watch out though, when you're in ketosis your blood sugar will be very low, and the alcohol will have a more pronounced effect.
http://www.lowcarb.com/
