Insulin is an important regulator of the metabolism of fat. Digestion breaks down
starches (a form of carbohydrate that is made up of long chains of glucose), proteins,
fats, and other carbohydrates in food into amino acids, fatty acids and simple
sugars (mostly glucose and variable amounts of fructose), all of which are first
processed by the liver. Glucose supplies energy to the body’s cells, some is converted
to glycogen, a ready source of energy, by the liver, and some is converted to
triglycerides that may end up stored as fat. When glucose and the other nutrients
are not metabolized in the liver and enter the general circulation, the pancreas is
signaled to release insulin.

Insulin drives energy storage by promoting synthesis
of glycogen and its storage in the liver and muscles, and insulin also promotes the
clearing of blood lipids into fat cells for storage in the form of triglycerides.
When the body’s immediate needs for glucose, the main energy source for all cells,
and the capacity to store glycogen are exceeded, the excess calories are stored as
fat. When stored energy is needed, the fat cells release triglycerides into the bloodstream.
They are then transported to the liver, where they are broken down into
ketones that serve as an energy source.

My UCSF colleague Robert Lustig has
described the process as follows: “Insulin makes fat—the more insulin, the more
fat. And there it sits…and sits…as long as there is insulin around. When the insulin
levels drop, the process goes into reverse: the triglycerides get broken down, causing
the fat cells to shrink—when that happens, that’s weight loss!”

This blog presents opinions and ideas and is intended to provide helpful general information. I am not engaged in rendering advice or services to the individual reader. The ideas, procedures and suggestions in that are presented are not in any way a substitute for the advice and care of the reader’s own physician or other medical professional based on the reader’s own individual conditions, symptoms or concerns. If the reader needs personal medical, health, dietary, exercise or other assistance or advice the reader should consult a physician and/or other qualified health professionals. The author specifically disclaims all responsibility for any injury, damage or loss that the reader may incur as a direct or indirect consequence of following any directions or suggestions given in this blog or participating in any programs described in this blog or in the book, The Building Blocks of Health––How to Optimize Your Health with a Lifestyle Checklist (available in print or downloaded at Amazon, Apple, Barnes and Noble and elsewhere). Copyright 2021 by J. Joseph Speidel