“HFLC diet works - period.”
Works great when combined with periodic and intermittent fasting, especially for those who want to lose body fat and control insulin.
See anything by Dr. Jason Fung. https://intensivedietarymanagement.com
HFLC may also help control cancer, too. See anything by Drs. Thomas Seyfried or Dominic D’Agostino.
Good for the soul, too.
There are so many resources, a few hours of googling will result in more reading than you have time for. But basically, just don't eat any grains, any sugars, or any polyunsaturated oils. That's right, no bread! No pasta, cake, cookies, ice cream, sweets! Basically no processed foods. Eat meat, fish, low-starch vegetables (with lots of cheese and butter), nuts (not legumes), eggs, cheese, heavy cream, butter, coconut oil, avocado. 86 or 90% chocolate (it's delicious and good for you!) Plain full-fat yoghurt but nothing lite, low-fat, etc. Small amounts of berries such as blueberries and strawberries. Occasional starchy veggies like potato -- some can get away with it, some can't.
Use MyFitnessPal for a few months to track your nutrients, until you have a feel for it. Check what your "macros" should be (carbs, fat, protein) by using https://keto-calculator.ankerl.com/. Get the keto plugin for MyFitnessPal so you can add the proper columns to your food tracking. Keep your daily carbs between 20 and 50 grams. It can vary based on how insulin resistant you are or how obese, or whatever. Expect to feel sh###y for a few days to a few weeks as your body accepts that fact that you aren't sending down any more carbs, and converts over to burning fats. It's called keto flu. It goes away.
I haven’t tried it with fasting but I might at some point this year.