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Fat

Fat is primarily ketogenic (90%) but also has a slight anti-ketogenic effect (10%). This
represents the fact that ten percent of the total fat grams ingested will appear in the
bloodstream as glucose (via conversion of the glycerol portion of triglycerides) (5,6). If 180 grams
of fat are oxidized (burned) per day, this will provide 18 grams of glucose from the conversion of
glycerol.

Alcohol

Although alcohol is not represented in the above equation, having no direct effect on
ketosis, alcohol intake will have an impact on the depth of ketosis and the amount of body fat
used by the body. As discussed in chapter 4, excessive alcohol intake while in ketosis can cause
runaway acidosis to develop which is potentially very dangerous. Additionally as alcohol intake
limits how much FFA can be processed by the liver, calories from alcohol will detract from overall
fat loss.

Summary

The three macronutrients are carbohydrate, protein and fat. All three nutrients have
differing effects on ketosis due to their digestion and subsequent effects on blood glucose and
hormone levels. Carbohydrate is 100% anti-ketogenic due to its effects on blood glucose and
insulin (raising both). Protein is approximately 46% ketogenic and 58% anti-ketogenic due to the
fact that over half of ingested protein is converted to glucose, raising insulin. Fat is 90%
ketogenic and ten percent anti-ketogenic, representing the small conversion of the glycerol
portion of triglycerides to glucose. While alcohol has no direct effect on the establishment of
ketosis, excessive alcohol intake can cause ketoacidosis to occur.

Section 2: Nitrogen sparing:

A theoretical approach

The breakdown of body protein during total starvation to produce glucose ultimately led
researchers to explore two distinctly different approaches to prevent this loss. The simplest
approach was to provide glucose in order to eliminate the need for protein breakdown. However,
this had a secondary effect of preventing the adaptations to ketosis. In some clinical situations
such as post-surgical trauma, providing glucose or glucose with protein caused greater protein
losses by preventing the adaptations to ketosis from occurring.

The second approach was to mimic the effects of starvation while consuming food. This
allows ketosis to develop while limiting the loss of body protein. One approach was to simply
consume high quality protein, which was called the protein sparing modified fast (PSMF).