First off, I am not a scientific expert on the ketones as fuel process. But I have successfully used a Keto diet to lose 60 lbs in four months and have experimented with 1) a low-calorie (800 per day) low-carbohydrate, low-fat, and high protein diet; and 2) a low-calorie (1300 per day), low-carbohydrate, high-fat, and high protein diet; and 3) a low-calorie 1000 per day), low-carbohydrate, low-fat, and moderate protein diet.
My nutritionist (and personal experience) tells me that sub-dermal fat burning ketosis is only possible once you have depleted your glycogen and are limiting your calories, including protein calories.
Humans have four “buckets” of fuel sources (in order of the body’s preference), 1) carbohydrates, 2) glycogen, 3) protein, 4) fat). If you consume too much fat and protein in your diet the body converts the protein to glucose and the consumed fats into ketones to use as fuel. In short, you need to be in a severe calorie deficit in order to burn sub-dermal fat.
Of course, everyone is different and some people may not digest, absorb, and synthesize fat as efficiently as others. So consumed fat may not be available for conversion to ketones.
There are sources on the internet that help explain these processes. Unfortunately, as a newbie I can’t post them.
I hope this helps.
