Tl;dr: What is the net joule value of fat if used for energy provision, compared to e.g. carbohydrates. So does 1 Joule Fat intake result in 1 - X Joule energy provided to the cell, or does it work in a completely different way?
My understanding is that if I take in one Joule of fat, my body takes in the energy to move ~100g of mass up by one meter (Wikipedia).
Now for my body to use that energy, it needs to convert it to some sort of Glucose, right?
From the Lipid Metabolism Wikipedia Article I get that my fat needs to become a Triglyceride to serve as energy source.
There are some steps involved, roughly the following:
- gastric peristalsis (basically muscle contractions to mix it all up)
- peristaltic contractions in the gut (again, mixing is key)
- lipase, also working in the gut to finally create Triglyceride
- then the fat gets "packaged" in Chylomicrons and put into the bloodstream
releasing energy to the cell involves the following
- Lipase unpacking the Chylomicrons
- Splitting of the Triglyceride in Glycerin (the stuff we want) and fatty acids
Now this seems like a really cumbersome process to me, and I wonder what the net Joule Value is that arrives at the cell. Is it significant, or is this process so efficient that it doesn't matter anyways?