More metabolism

Or, as I like to title it, "The Day The Biochem Girls Learn That Atkin's Diet Doesn't Work, and Why".

The short version of the answer probably doesn't make much sense, because it is "if Atkin's diet worked, a lot of people wouldn't be suffering from diabetes".

The less condensed version is this: the carbohydrates that we eat, i.e. carbs, get processed in a series of steps called the "glycolysis", giving us pyruvate (a chemical compound). Pyruvate can either enter the Kreb's cycle (another series of metabolic pathways) via pyruvate decarboxylase (an enzyme) into acetyl CoA (CoA is short for Coenzyme A, acetyl is basically acetate, the chemical, when it's attached to something else), or it can processed via pyruvate carboxylase (another enzyme) into oxaloacetate (OAA, another chemical). Fat (or fatty acyls, as I'm forced to remember them as) is what people try to get rid of when they go on a diet, and fat can only be "gotten rid of" by burning, i.e. metabolizing it. Fat can only be processed ("changed") to acetyl CoA, but not OAA.

All of which is all well and very good if not for the fact that fat has a lot of carbon molecules in it and we get rid of most of our carbon molecules in the Kreb's cycle, and in order for Kreb's cycle to be efficient, we need BOTH acetyl CoA AND oxaloacetate.

Therefore, the people who are on the diet are skimping their carbs and so their oxaloacetate eventually runs low and instead of efficient fat burning the body starts making ketone bodies instead. This is the same as what happens in certain type of diabetes -- i.e. the type that is due to the cell's inability to get the carbs inside of itself. Poor, carb-starved cells also make ketone bodies which leak out ...I think some in the urine, some in the saliva, etc.

I am getting an education. Scary, isn't it?