I'm only joking about girl thing haha.
You can do a lot of cardio, but if you cut calories too drastic you'll start to feel too terrible beyond the point that taking electrolytes can help. Honestly, you can probably get away with doing that much cardio for the few days after your initial cheat day. Just listen to your body, it'll tell you when you can't do it anymore.
Lyle Mcdonald has a book about this exact thing I just wrote called Rapid Fat Loss (https://www.amazon.com/Rapid-Fat-Loss-Handbook-Scientific/dp/0967145643) which is worth a read if you're interested. He doesn't touch too much on the super or morbid obese people using this diet except for the fact that they can do it for a very long time with no side effects as long as they take the electrolyte supplements.
If you want to deviate from the plan in the book, you can actually skip the keto part and eat carbs, I've done it some weeks and haven't noticed a difference except for the occasional hunger pains. Honestly you should focus on shoving as much protein down as you can and the rest of your food shouldn't contribute much to the other macro nutrients at all. One thing to consider too, if you want to rotate this diet out with a normal deficit diet then Keto is probably going to be a lot easier to rotate without the urges to binge eat.
In an ideal world, everyone would take a long-term approach to dieting, trying to lose weight/fat gradually. They’d make small changes to their eating habits, activity patterns, or both. But we don’t live in an ideal world there are situations when that simply won’t work. Or where people simply aren’t willing to be patient. Maybe they need to drop weight fast for a special event, or they are an athlete or bodybuilder who has to get in shape and is under a time crunch. Maybe they just want the diet over as quickly as possible. Whatever the case, sometimes you need a way to drop both weight and fat quickly to reach your goals. That’s where The Rapid Fat Loss Handbook: A Scientific Approach to Crash Dieting comes in.
http://www.amazon.com/The-Rapid-Fat-Loss-Handbook/dp/0967145643
Well.. IMHO you can't do better than this...
http://www.amazon.com/Rapid-Fat-Loss-Handbook-Scientific/dp/0967145643
For speedy fat cutting. But basically that book, like almost any diet book worth anything, will advocate a cyclic ketogenic style diet. (note if you don't need speed then just a regular cyclic keto diet is cool. The main difference is amount of calories. The above book is really a temporary diet for a fast cut)
Specifically to answer your main question...
> how to cut as much fat as possible while keeping as much muscle as > possible?
Lean mass is protected by eating enough protein. (estimates are .5-1g / kg lean body mass )
So basically you want to cut calories, ensure you have enough protein, ensure your basic essential nutrient needs are met (fish oil and multivitamin and green veggies helps here).
And the 2nd part.. eat carbs once a week near or just above maintenance bmr. Why? Without getting into detail, it essentially tricks your body into thinking.. hey I'm not starving! I can continue to lose weight. But there is a well documented scientific body of research under that idea.
Thank you for your response. Would cod liver oil (from the tin, I have cod livers in the house) do? Would I need to count the fat? Presumably only a small amount is required? I do need to supplement electrolytes on low carb so will keep that going and get a multivitamin.
I see what you mean. I'd love to buy the book however as you can see it is ridiculously expensive in the UK: https://www.amazon.co.uk/Rapid-Fat-Loss-Handbook-Scientific/dp/0967145643/ref=sr_1_1?dchild=1&keywords=rapid+fat+loss+handbook&qid=1625828343&sr=8-1
I'll see if I can find it elsewhere.
> rapid fat loss handbook
But now I see there is an updated one in a kindle version for $5, but people say the links are all broken so it's not usable. https://www.amazon.com/Extreme-Rapid-Fat-Loss-Handbook-ebook/dp/B00NK15JFW/ref=sr_1_1?ie=UTF8&qid=1501534769&sr=8-1&keywords=rapid+fat+loss+handbook
/r/psmf
gogogoogo
edit: wow that book is expensive on there what the f