I guess the recommended ratio of 65-70%fat, 25-30% protein and 4-6% carbs has developed from the fact that our body burns energy in the backwards order. First it relies on carbs for fuel (or alcohol), then protein and lastly fat. Since our goal is to stick to 20g carbs during induction, the protein and fat have to be "distributed" optimally (is there such a word?). The more fat we eat, the more the body has to rely on burning already stored fat (the whole idea of ketosis). But we also need a certain (adequate) amount of protein, for our muscles sake f.ex. And since another rule of thumb is to eat our bodyweight in lbs x 10-12 (depending on lifestyle), this percentage ratio has been proven to work for most people in order to get enough (high amounts of) fat and adequate amounts of protein while staying on 20g carbs.

The percentage ratio will change slightly during OWL an onwards (fat % will get lower as the carb % gets higher.)

Some people, with a metabolic resistance, are recommended to try the so called "Fat Fast" - but only if this resistance has been thoroughly proven. Then the fat% is drastically raised (up to 90%) for a week or two, in order to speed up the burning of stored fat.

Another way of kick starting is to follow the KISS (Keep It Simple, Sweetie) regimen for a couple of weeks. KISS is basically a stricter version of Induction, with no processed food at all. Here are the Rules for Kiss. And here are some other Guidelines for Kiss. There is a KISS challenge thread on this forum as well.

So, now I think I've confused everybody even more.

/gil