Discipline Equals Freedom Field Manual by Jocko Willink ( PDFDrive.com )

insulin pushes the sugar in the blood into fat cells
and also slows down the process of fat in the fat
cells being pulled out and used for energy.
Obviously, when your body is putting fat into fat
cells and not using your fat for energy, you get
fatter.
In order to use the fat in your body for energy, the
body must have gone through its most readily
available source of energy: glucose or sugar in the
blood. Once that is depleted, the body begins to
utilize fat for energy. You can deplete that sugar in
the blood by exercising until it is gone, fasting
until it is gone, or adjusting your carbohydrate
intake.
There are other extremely negative effects of
continued elevated insulin levels in the blood beyond
gaining or maintaining body fat. Consistent spiking
of insulin in the blood can lead to insulin
resistance, which can eventually lead to type 2
diabetes. Other long-term impacts that prolonged
elevated insulin levels can cause are heart disease,
diabetic retinopathy (blindness), strokes, and kidney
failure. Not good.
So, the solution seems obvious: Stop eating
carbohydrates—or at least minimize carbohydrate
intake.
Why is that so hard? The answer is simple:
Carbohydrates are addictive. Yes, sugar is like a
drug in your brain and causes neurochemical responses
similar to drugs like heroin.