Taken from Reddit Keto Boards @ http://www.reddit.com/help/faq...
The Standard Ketogenic Diet (SKD)
What is keto?
The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet. The diet mimics aspects of starvation by forcing the body to burn fats rather than carbohydrates. Normally, the carbohydrates contained in food are converted into glucose, which is then transported around the body and is particularly important in fueling brain function. However, if there is very little carbohydrate in the diet, the liver converts fat into fatty acids and ketone bodies. The ketone bodies pass into the brain and replace glucose as an energy source. Ketosis is the state characterized by elevated levels of ketone bodies in the blood. Very simply put ketosis is when your body stops using glucose for energy and instead uses fat broken down into ketones.
Will a ketogenic diet work for me?
Probably. Some people respond better to it than others, but most people seem to respond to it pretty well. Sometimes people have problems in the beginning (fuzziness in the head and problems concentrating are the common complaints with these people) and can't seem to make the adjustment. If you're one of these people the diet may not be worth it for you. Most of the time, however, those feelings only last for a few days to a week and are most severe the first time you go into ketosis.
How do I get started?
Pretty simply just start limiting your net daily carb intake to 50g or less. This is adequate for most people but you may need to go lower. Your macro-nutrient goals should be about 60% fat, 35% protein and the other 5% carbs. It's OK if the fat and protein numbers fluctuate but keep your carb intake to 5% or less. This means you'll be eating things like whole eggs, fish, beef, chicken and turkey, green vegetables, extra virgin olive oil, cheese, butter, cream, nuts, seeds and, of course, bacon.
How do I know if I'm in ketosis?
The short answer is that if your carb intake is low enough you'll be in ketosis. It may take a couple of weeks the first time. Ketostix can show you if you're in ketosis by measuring the excess ketones in your urine. If you're hydrated well enough or if you're using all the ketones for energy you could be in ketosis without getting a positive result on the ketositx. Some people notice a metallic taste in their mouth or a strong smell of their urine.
How long should I do keto?
For as long as it's working for you or until you reach your goals. If you find you're regularly running out of energy but still haven't reached your fat loss goals you might want to switch to a CKD or TKD.
How many carbs should I be eating?
A ketogenic diet is generally one with fewer than 50g of carbs making up no more than 10% of your calories per day. A low-carb diet is generally considered one with less than 200g of carbs a day, making up between 10-20% of total calories. A low-carb diet is not designed to induce ketosis.
If I'm doing keto do I still need to count calories?
Yes and no. For some people simply cutting out all the carbs lowers their total caloric intake low enough to lose weight. For others they still need to focus on eating less and should keep track of their calories. Even the first group of people, however, would benefit from logging their food intake at least occasionally to get an idea of how many calories they're eating and what the macro-nutrient breakdown is. Although it's more difficult, you can still gain fat on a ketogenic diet so you can't go hog wild on things like bacon and cheese.
Vegetables are high in carbs, should I stop eating them?
No, absolutely not. While they're high in carbs, most of those carbs are in the form of fiber. Fiber isn't broken down and absorbed by your body so it's not counted towards your carb total. For example, one cup of Avocado cubes has about 10g of carbs, but 7 of them are fiber so you'd only count 3g towards your daily carb total. Most vegetables are also low calorie so they're good filler foods. They're also full of necessary nutrients.
Isn't ketosis bad for me? I heard it'll destroy my liver.
If you've got pre-existing liver damage or are diabetic you should consult a doctor before starting a ketogenic diet. A ketogenic diet is not bad for an otherwise healthy individual.
What are some good keto snacks?
Nuts and seeds (be careful as they do have carbs), cheese, cured meats, pork rinds, celery and peanut butter, greek yoghurt, cottage cheese, hard boiled eggs.
What comes after keto?
If you've reached your fat loss goals there would be no need to continue with a standard ketogenic diet. You can switch to a TKD, CKD or a diet with a more even ratio of carbs/protein/fat. If you do the latter make sure to slowly increase your carb intake 5-10g a week to avoid triggering large insulin spikes.
Variations of the ketogenic diet
If you're very active or have already lost most of your fat the Standard Ketogenic Diet may not be giving you enough energy for your workouts. There are some variations that are designed to provide energy for workouts, keeping or even building muscle mass while continuing to burn fat. If you've never done a ketogenic diet before it's recommended to do the SKD for at least a couple of weeks before moving on to one of these alternatives.
The Cyclical Ketogenic Diet (CKD)
Once your body uses up all it's stores of glycogen (basically glucose storage units) it'll turn to fat, produce ketones from it, and use that as fuel. That works fine for day to day activities but may not provide your muscles with enough energy for intense workouts. The CKD takes care of that. Generally it's 5-6 days of an SKD followed by 24-36 hours of a carb-up. The point of the carb-up is to refill your muscles with glycogen without creating additional fat stores. Generally the carb-up starts just before or right after an intense, full body workout. This article by Lyle McDonald goes into great detail about the CKD, types and amounts of carbs to use and proper timing.
The Targeted Ketogenic Diet (TKD)
The TKD is similar to the CKD, but instead of carb-ups there is carb intake centered around the workout. This provides fuel for the workout without knocking you out of ketosis for very long, if at all. This forum post at AnabolicMinds talks about the TKD.