M.E SCIENCE
By Warren Germishuizen
CARB
BACK
M A NY O F
YOU OUT
MIGHT HA
THERE
V
E
H
E
A
THE TERM
RD OF
C
A
R
LOADING
B BACK-
,
B
U
T
A EN’T TO
SURE WH
AT IT AL R
L ENTAILS O
.
LOADING
CARBOHYDRATES AND INSULIN
F
irstly, the most important thing that you need to know is that
all carbohydrates – both low-glycaemic and high-glyacemic
index carbs - will elicit an insulin response from the pancreas.
Whether the pancreas secretes a large once-off amount or a slow
systematic release of insulin will be determined by the nature of the
carbohydrate. The relevance of discussing this topic is that we have a
way of manipulating our bodies by the way we eat our food.
Insulin is one of the most anabolic hormones in the body. It can be
extremely helpful and beneficial to us if we intend building muscle,
but, as part of a double-edged sword, it can be just as detrimental
to us because it can drive nutrients to the fat cells where they will be
stored within our fat depositories - not a desirable effect at all.
It is important for you to understand how insulin functions in the
body, to understand the cascade of events
that are triggered when insulin is released.
When carbohydrates are broken down
into glucose, these “sugars” need to find a
way into the cells. Insulin doesn’t do the
actual work of driving the sugars into the
cells though, that is the function of glucose
transporters (GLUTs). We currently know of
14 of these transporters, GLUT4 perhaps
being the most important. Rather than
shuttling sugar molecules through the cell
20
Muscle Evolution
Gal bladder
membranes, insulin recruits GLUT4s to do the work. When not active or
activated, GLUT4 protein s are tucked away within the cell membranes
doing nothing and are dormant.
Liver cells, striated muscle and fat cells are tissues containing high
amounts of GLUT4 proteins within their cell membranes. Once insulin hits
the cells containing the GLUT4 proteins, these proteins start moving to
the surface of the cells, in a process called translocation. They then grab
the sugar molecules and move them into the cells. The cells can then use
these sugars as energy, or they will be stored as energy for later.
Insulin sensitivity describes how reactive a cell is to the insulin-
triggered translocation of GLUT4 proteins from the interior of the cell to
the exterior where they do their work. If cells fail to
Liver
react to insulin, GLUT4 proteins move slowly and
only partially to the surface. Total insulin resistance
would mean that these GLUT4 proteins don’t move
at all in the presence of insulin. Unfortunately, as
we get older we develop a certain level of insulin
resistance. We have, however, discovered some
useful information about insulin sensitivity and
how it has a definite relationship with the time of
the day. In the morning GLUT4 proteins react more
strongly to insulin than in the evening.
Pancreas
I
T NEEDS TO BE DISSECTED QUITE
CAREFULLY AS THERE ARE A NUMBER
OF DIFFERENT CONCLUSIONS FROM
RESEARCHES AND SCIENTISTS ABOUT
HOW THIS TYPE OF DIET AFFECTS THE
PHYSIOLOGY OF THE BODY.