Animal fats are best as humans have developed on it for 100k of years. Plant/seed oils are only about 120y old and were initially developed as grease for machines.
The body always uses more than one fuel substrate at any time (redundancy). It's just when consuming lots of carbs, it will be used first and hence more glucose in relation to fat is used.
The metabolic pathway into and out of your fat cells is a one way street. Either in or out. When you're in ketosis your fat cells are exporting triglycerides into your blood stream to be broken down and used as energy. When you eat carbohydrates your glucose becomes elevated and that pathway runs the other way taking in glucose and packaging it into triglycerides. There's a little more to it but that's basically how it works.
👍 thanks.
