At 06:42 PM 02/20/2001 -0500, Ming wrote:
  Besides glucose,
>protein (amino acids) can also induce an insulin response.  In his NHE
>book, Faigin states that the sensitivity of induction by protein is 30%
>relative to that by glucose (units?).

Westphal, et al (Am J Clin Nutr 1990;52:267-72), measured insulin response
to a meal with 50g glucose and a meal with 50g protein, from cooked lean
hamburger (6.5% fat), as well as other combinations of glucose and protein.
The peak insulin response for the glucose meal was about 63 uU/ml above
baseline and occurred 45 minutes after ingestion. The peak insulin response
for the protein meal was about 10 uU/ml above baseline and occurred 90
minutes after ingestion, although the curve is nearly flat from 30 minutes
until 120 minutes after ingestion. They do not present data for the area
under the curve, however it is quite clear that the insulin response to the
glucose meal greatly exceeds that of the protein meal. Other combinations
tested were 50g glucose combined with either 10g, 30g, or 50g of protein.
Each of these curves closely resemble the glucose-only curve. I must
conclude from this data that the insulin response to protein is quite a bit
smaller than that given by Faigin and nearly insignificant.

Interestingly, their data also show that there is a mild glucose increase
in response to ingestion of protein. Protein ingestion in the absence of
glucose causes the secretion of glucagon, which in turn liberates glucose
from storage. It may be this "secondary" glucose which is responsible for
the insulin response due to protein ingestion.

John