Sunday, March 4, 2012

Eat fat and grow slim

Eat Fat AND Grow Slim is the title of a book from the 1950s that suggests a high fat, zero carb diet to lose weight.  The theory is that the body creates pyruvic acid out of carbs, and the pyruvic acid turns into fat and inhibits using fat for fuel.  If you don't eat carbs then little or no pyruvic acid is created.

Mr. Fatten-Easily's trouble is thought to be his inability to oxidise pyruvic acid properly—the so called pyruvic acid block .
He gets stuck with large quantities of pyruvic acid which is bad for him in two ways:
  1. He cannot readily use it for energy, so he takes it by a short cut to his fat stores.
  2. It prevents the mobilisation of fat from his fat stores by inhibiting the oxidation of fatty acids.
If a fat man stops eating carbohydrate, he makes little pyruvic acid and removes the stimulus to his "fat organ" to make fat. By eating fat and protein he by-passes his metabolic block.

Here is some terminology:
Glycolysis is the is the metabolic pathway that converts glucose (C6H12O6), into pyruvate, (CH3COCOO + H+).
Glycogenesis aka glycogenolysis is the process of glycogen synthesis, in which glucose molecules are added to chains of glycogen for storage. This process is activated during rest periods following the Cori cycle, in the liver, and also activated by insulin in response to high glucose levels, for example after a carbohydrate-containing meal.
Gluconeogenesis (abbreviated GNG) is a metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as lactate, glycerol, and glucogenic amino acids.
Ketogenesis is the process by which ketone bodies are produced as a result of fatty acid breakdown.  Ketone bodies are produced mainly in the mitochondria of liver cells. Its synthesis occurs in response to low glucose levels in the blood, and after exhaustion of cellular carbohydrate stores, such as glycogen. Ketosis is a state of having elevated ketone bodies in the body.

The three ketone bodies are:
  • Acetoacetate, which, if not oxidized to form usable energy, is the source of the two other ketone bodies below
  • Acetone, which, unlike free fatty acids, can be used by the brain for energy. Acetone is generated through the decarboxylation of acetoacetate which may occur spontaneously or through the enzyme acetoacetate decarboxylase.
  • β-hydroxybutyrate, which is not, in the technical sense, a ketone according to IUPAC nomenclature. It is generated through the action of the enzyme D-β-hydroxybutyrate dehydrogenase on acetoacetate.

In plain English, glycogenesis is the process by which the body turns excess glycogen (carbs) into fat.  Ketogenesis is the process by which the body turns excess fat into glucose (energy).  Gluconeogenesis (GNG) is the process by which the body converts muscle into glucose.  So the challenge is to switch the body from glycolysis into ketogenesis without entering gluconeogenesis.  There are 3 modes and your body will only be in one of them at a time.

When the body is in GNG (aka "starvation mode"), the body's metabolism slows down, it burns muscle and stores fat.  So this is very bad.  Also eating too much protein can cause GNG as the body converts it into fuel.  Eating moderate amounts of protein will keep the body from entering GNG.

A ketogenic diet will keep the body in ketosis.

Here is information on a ketogenic diet:
The ketogenic diet is a high-fat, adequate-protein, low-carbohydrate diet that in medicine is used primarily to treat difficult-to-control (refractory) epilepsy in children. The diet mimics aspects of starvation by forcing the body to burn fats rather than carbohydrates. Normally, the carbohydrates contained in food are converted into glucose, which is then transported around the body and is particularly important in fuelling brain function. However, if there is very little carbohydrate in the diet, the liver converts fat into fatty acids and ketone bodies. The ketone bodies pass into the brain and replace glucose as an energy source. An elevated level of ketone bodies in the blood, a state known as ketosis, leads to a reduction in the frequency of epileptic seizures.

The original therapeutic diet for pediatric epilepsy provides just enough protein for body growth and repair, and sufficient calories to maintain the correct weight for age and height. This classic ketogenic diet contains a 4:1 ratio by weight of fat to combined protein and carbohydrate. This is achieved by excluding high-carbohydrate foods such as starchy fruits and vegetables, bread, pasta, grains and sugar, while increasing the consumption of foods high in fat such as cream and butter.

Who knew that the treatment for epilepsy was also a great way to lose weight?

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