The
Whey To Weight Loss (Part I)
By
Will Brink
Regular readers
of my work have come to expect articles about the power of whey
proteins to potentaily fight cancer and improve immunity among
its many benefits. The ability of whey to fight cancer, improve
glutathione levels and immunity, is well documented.
Additional research suggests possible medical uses for whey that
are quite unexpected and different from whey’s traditional role
as an immune booster and anti cancer functional food. For example,
whey may be able to reduce stress and lower cortisol and increase
brain serotonin levels, improve liver function in those suffering
from certain forms of hepatitis, reduce blood pressure, as well
as other amazing recent discoveries, such as whey’s possible effects
on weight loss, which is the focus of this article.
What is whey?
When we talk about whey we are actually referring to a complex
milk-based ingredient made up of protein, lactose, fat and minerals.
Protein is the best-known component of whey and is made up of
many smaller protein subfractions such as: Beta-lactoglobulin,
alpha-lactalbumin, immunoglobulins (IgGs), glycomacropeptides,
bovine serum albumin (BSA) and minor peptides such as lactoperoxidases,
lysozyme and lactoferrin.
Each of the subfractions found in whey has its own unique biological
properties. Modern filtering technology has improved dramatically
in the past decade, allowing companies to separate some of the
highly bioactive peptides - such as lactoferrin and lactoperoxidase
- from whey.
Some of these subfractions are only found in very minute amounts
in cow’s milk, normally at less than one percent (e.g., lactoferrin,
lactoperoxidase, etc.)
The medicinal properties of whey have been known for centuries.
For example, an expression from Florence, Italy. Circa 1650, was
"Chi vuol viver sano e lesto beve scotta e cena presto" which
translates into English as "If you want to live a healthy and
active life, drink whey and dine early."
Another expression from Italy regarding the benefits of whey (circa
1777) was "Allevato con la scotta il dottore e in bancarotta."
Which translates into English "If everyone were raised on whey,
doctors would be bankrupt."
Is whey a weight loss functional food?
A few years ago, I might have said no. Now I am not so sure. Although
there was a smattering of studies suggesting whey had certain
properties that might assist with weight loss, a number of recent
studies appear to further support the use of whey as a possible
weight loss supplement. Most interesting - at least to nerds like
me - the effect appears to be not by a single mechanism, but several.
This article will briefly explore a few possible pathways by which
whey may assist the dieter.
"I’m hungry!"
Human hunger and appetite are regulated by a phenomenally complicated
set of overlapping feedback networks, involving a long list of
hormones, psychological factors as well as physiological factors,
all of which are still being elucidated. It’s a very intensive
area of research right now, with various pharmaceutical companies
looking for that "magic bullet" weight loss breakthrough they
can bring to market.
One hormone getting attention by researchers looking for possible
solutions to obesity is cholecystokinin (CCK). Several decades
ago, researchers found CCK largely responsible for the feeling
of fullness or satiety experienced after a meal and partially
controls appetite, at least in the short term.
Cholecystokinin (CCK) is a small peptide with multiple functions
in both the central nervous system and the periphery (via CCK-B
and CCK-A receptors respectively). Along with other hormones,
such as pancreatic glucagon, bombesin, glucagon-like peptide-1,
amide (GLP-1), oxyntomodulin, peptide YY (PYY) and pancreatic
polypeptide (PP)., CCK is released by ingested food from the gastrointestinal
tract and mediates satiety after meals.
Such a list would not be complete without at least making mention
of what many researchers consider the "master hormones" in this
milieu, which is insulin and leptin. If that’s not confusing enough,
release of these hormones depends on the concentration and composition
of the nutrients ingested.
That is, the type of nutrients (i.e., fat, protein, and carbohydrates)
eaten, the amount of each eaten, and composition of the meal,
all effect which hormones are released and in what amounts...
Needless to say, it’s a topic that gets real complicated real
fast and the exact roles of all the variables is far from fully
understood at this time, though huge strides have been made recently.
Whey’s effects on food intake.
This (finally!) brings us to whey protein. Whey may have some
unique effects on food intake via its effects on CCK and other
pathways. Many studies have shown that protein is the most satiating
macro-nutrient. However, it also appears all proteins may not
be created equal in this respect.
For example, two studies using human volunteers compared whey
vs. casein (another milk based protein) on appetite, CCK, and
other hormones (Hall WL, Millward DJ, Long SJ, Morgan LM.Casein
and whey exert different effects on plasma amino acid profiles,
gastrointestinal hormone secretion and appetite. Br J Nutr. 2003
Feb;89(2):239-48).
The first study found that energy intake from a buffet meal ad
libitum was significantly less 90 minutes after a liquid meal
containing whey, compared with an equivalent amount of casein
given 90 minutes before the volunteers were allowed to eat all
they wanted (ad libitum) at the buffet. In the second study, the
same whey preload led to a plasma CCK increase of 60 % ( in addition
to large increases in glucagon-like peptide [GLP]-1 and glucose-dependent
insulinotropic polypeptide) following the whey preload compared
with the casein.
Translated, taking whey before people were allowed to eat all
they wanted (ad libitum) at a buffet showed a decrease in the
amount of calories they ate as well as substantial increases in
CCK compared to casein. Subjectively, it was found there was greater
satiety followed the whey meal also.
The researchers concluded "These results implicate post-absorptive
increases in plasma amino acids together with both CCK and GLP-1
as potential mediators of the increased satiety response to whey
and emphasize the importance of considering the impact of protein
type on the appetite response to a mixed meal." Several animal
studies also find whey appears to have a pronounced effect on
CCK and or satiety over other protein sources.
It should be noted however that not all studies have found the
effect of whey vs. other protein sources on food intake (Bowen
J, Noakes M, Clifton P, Jenkins A, Batterham M.Acute effect of
dietary proteins on appetite, energy intake and glycemic response
in overweight men. Asia Pac J Clin Nutr. 2004;13(Suppl):S64.).
It should also be noted that although studies find protein to
be the most satiating of the macro-nutrients, certain protein
sources (e.g. egg whites) may actually increase appetite (Anderson
GH, Tecimer SN, Shah D, Zafar TA. Protein source, quantity, and
time of consumption determine the effect of proteins on short-term
food intake in young men. J Nutr. 2004 Nov;134(11):3011-5.), so
protein sources appear worth considering when looking to maximize
weight loss and suppress appetite.
How whey achieves this effect is not fully understood, but research
suggests it’s due to whey’s high glycomacropeptide and alpha-lactalbumin
content, as well as its high solubility compared to other proteins,
and perhaps it’s high percentage of branch chain amino acids (BCAA’s).
Whey’s effects on body fat, insulin sensitivity, and fat
burning... .
So we have some studies suggesting whey may have some unique effects
on hormones involved in satiety and or may reduce energy (calorie)
intake of subsequent meals, but do we have studies showing direct
effects of whey vs. other proteins on weight loss? In animals
at least, whey has looked like a promising supplement for weight
loss.
Although higher protein diets have been found to improve insulin
sensitivity, and may be superior for weight loss (with some debate!)
then higher carbohydrate lower protein diets, it’s unclear if
all proteins have the same effects.
One study compared whey to beef (Damien P. Belobrajdic,, Graeme
H. McIntosh, and Julie A. Owens. A High-Whey-Protein Diet Reduces
Body Weight Gain and Alters Insulin Sensitivity Relative to Red
Meat in Wistar Rats. J. Nutr. 134:1454-1458, June 2004) and found
whey reduced body weight and tissue lipid levels and increased
insulin sensitivity compared to red meat.
Rats were fed a high-fat diet for nine weeks, then switched to
a diet containing either whey or beef for an additional six weeks.
As has generally been found in other studies, the move to a high
dietary protein reduced energy intake (due to the known satiating
effects of protein compared to carbs or fat), as well as reductions
in visceral and subcutaneous bodyfat.
However, the rats getting the whey, there was a 40% reduction
in plasma insulin concentrations and increased insulin sensitivity
compared to the red meat. Not surprisingly, the researchers concluded
"These findings support the conclusions that a high-protein diet
reduces energy intake and adiposity and that whey protein is more
effective than red meat in reducing body weight gain and increasing
insulin sensitivity."
Other studies suggest taking whey before a workout is superior
for preserving/gaining lean body mass (LBM) and maintaining fat
burning (beta oxidation) during exercise over other foods taken
prior to a workout. The study called "A preexercise lactalbumin-enriched
whey protein meal preserves lipid oxidation and decreases adiposity
in rats" (Am J Physiol Endocrinol Metab 283: E565-E572, 2002.)
came to some very interesting conclusions.
One thing we have known a long time is the composition of the
pre-exercise meal will affect substrate utilization during exercise
and thus might affect long-term changes in body weight and composition.
That is, depending on what you eat before you workout can dictate
what you use for energy (i.e. carbs, fats, and or proteins) which
alters what you burn (oxidize) for energy.
The researchers took groups of rats and made the poor buggers
exercise two hours daily for over five weeks (talk about over
training!), either in the fasted state or one hour after they
ingested a meal enriched with a simple sugar (glucose), whole
milk protein or whey protein.
The results were quite telling. Compared with fasting (no food),
the glucose meal increased glucose oxidation and decreased lipid
oxidation during and after exercise. Translated, they burned sugar
over body fat for their energy source. In contrast, the whole
milk protein and whey meals preserved lipid oxidation and increased
protein oxidation. Translated, fat burning was maintained and
they also used protein as a fuel source.
Not surprisingly, the whey meal increased protein oxidation more
than the whole milk protein meal, most likely due to the fact
that whey is considered a "fast" protein that is absorbed rapidly
due to it’s high solubility.
As one would expect, by the end of the five weeks, body weight
was greater in the glucose, whole milk protein and whey fed rats
than in the fasted ones. No shock there. Here is where it gets
interesting: In the group getting the glucose or the whole milk
protein, the increase in weight was from bodyfat, but in the whey
fed group, the increase in weight was from an increase in muscle
mass and a decrease in bodyfat!
Only the rats getting the whey before their workout increased
muscle mass and decreased their bodyfat. The researchers theorized
this was due to whey’s ability to rapidly deliver amino acids
during exercise. Is this the next big find in sports nutrition
or those simply looking to preserve muscle mass loss due to aging?
Hard to say at this time being it was done in rats, but if it
turns out to be true in humans (and there is no reason people
can’t try it now) it would indeed be a breakthrough in the quest
to add muscle and lose fat.
About the Author: More from sports nutrition expert and industry
author Will Brink: Online Articles: http://www.brinkzone.com/onlinearticles.html
Muscle Building: http://www.musclebuildingguide.com/
Diet Supplements: http://www.dietsupplementsreview.com/
Subscribe to the Glutathione
Report newsletter to learn more about safe, natural ways to optimize
glutathione levels
