Ed wrote:
> I also seem to remember reading that by slowing down the conversion of carbs
> to glucose, say by adding fat, has the benefit that if some part of the food
> makes it to the intestines before conversion, then the glucose is less
> likely to end up in the bloodstream. In other words, absorbtion of the
> glucose is cut down if the food enters the intestines from the stomach.
> Anyone else concur with this?
> ed

Nope. A mono-saccharide (like pure glucose) actually starts to be
absorbed through the buccal mucosa in the mouth. Saliva starts the
enzymatic breakdown of the di-saccharides like table sugar, as saliva
contains amylase.

The more complex the carb, the more the body has to break it down to the
simple structures that it can absorb. Most of this happens in the
intestinal lumen beyond the stomach.

The exocrine pancreas produces three sets of enzymes (or their
precursors), trypsin for protein, lipase for fats, and amylase for
carbs. It also releases bicarb to neutralize the strong acid coming from
the stomach.

So if you had a complex carb meal, the amylase needs time to break down
the poly- or oligo-saccharides into simpler structures like maltose,
which is two glucose molecules stuck together into another di-saccharide.

While all this is happening, the trypsin is breaking down the protein
into amino acids, and the lipase is doing the same thing to the fats,
producing free fatty acids (FFAs). Parenthetically, you also need bile
salts, made by the liver and stored in the gallbladder, to break down
the triglycerides and allow their absorption.

Since we tend to eat foods that contain fat, protein and carbs together,
the fats coat the carbs, and that fat has to be enzymatically stripped
off the carbs before the amylase can get to them. That is why fat delays
the appearance of glucose from carbs, and is the principal reason for
"Pizza Effect".

Aside from some minor losses in processing, the AUC for glucose vs. time
will be essentially the same for pure glucose, complex carbs, and carbs
coated in fat.

All this might be somewhat OT in AFD, but this is where you asked.

Jim