The Keto diet basics involves going long spells on extremely low (no higher than 30g per day) to almost zero g per day of carbs and increasing your fats to a really high level (to the point where they may make up as much as 65% of your daily macronutrients intake.) The idea behind this is to get your body into a state of ketosis. In this state of ketosis the body is supposed to be more inclined to use fat for energy- and research says it does just this. Depleting your carbohydrate/glycogen liver stores and then moving onto fat for fuel means you should end up being shredded.
You then follow this basic platform from say Monday until Sat 12pm (afternoon) (or Sat 7pm, depending on whose version you read). Then from this time until 12 midnight Sunday night (so up to 36 hours later) do your massive carb up...(Some say, and this will also be dictated by your body type, that you can go nuts in the carb up and eat anything you want and then there are those that more wisely- in my view- prescribe still sticking to the clean carbs even during your carb up.)
So calculating your numbers is as simple as the following...
Calculate your required maintenance level of daily calories...
(if you are looking to drop quickly use 13- I would not advise this, if you want a more level drop in body fat use 15 and if you are going to actually attempt to maintain or possibly put on some lean muscle mass then use 17)
Body weight in pounds x 15= a
Protein for the day 1g per body weight in pounds= b
Bx4=c (c= number of calories allotted to your daily protein allowance).
a-c= d (d= amount of calories to be allotted to fat intake).
D/9= g per day of fat to be consumed.
The end calculation should leave you with a very high number for your fat intake.
Now for those of you wondering about energy levels... Especially for training because there are no carbs, with there being such a high amount of fat in the diet you feel quite full and the fat is a very good fuel source for your body. (One adaptation that I have made is to actually have a nice fish fillet about an hour before I train and I find it gives me enough energy to get through my workout.) (I am aware of the arguments made to not have fats 2-3 hrs otherwise of training. While I won't have fats 2-3 hrs after training as I want quick absorption and blood flow then, I see no issue with slowing everything down before training so my body has access to a slow digesting energy source).
Continuing with general guidelines...
There are some that say to have a 30g carb intake immediately after training- just enough to fill liver glycogen levels. And then there are those that say having even as much as that may push you out of ketosis- the state you are trying to maintain. As I have done the post-workout shake for the last 8+ years of my training I have decided to try the "no post-workout" route! I figure I may as well try!
During my carb up period- for the sake of those who would like to know of you can get in shape and sill eat the things you want (in moderation)- for the first six weeks I will be relaxed about what I eat in this period but then the following 6 weeks I will only eat clean carbs.
I also like to make sure that the first workout of the week- as in a Monday morning workout- is a nice long full hour of work so I start cutting into the liver glycogen already. I also make sure to have one last really grueling workout on Saturday before my carb up. And I am eating a lot of fish,eggs,olive oil and beef!