Editor's Note: Will Brink's articles are
incredibly in-depth and this one is no exception. There is lots of great
information here on how whey may help aid in weight loss, but it does get a
little "heavy" in some sections. This is an important article for any guy
that consumes whey protein as a part of their daily diet so I've highlighted
the key points throughout the article.
Regular readers of my work have come to expect articles about the power of
whey proteins to potentially fight cancer and improve immunity among its many
benefits. The ability of whey to fight cancer, improve glutathione levels and
immunity, is well documented. Readers interested in brushing up on the effects
of whey on cancer, read my previous article titled,
Fighting Cancer with Whey.
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 macronutrient. 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 macronutrients, 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!) than
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.
Effects on Serotonin, Blood Sugar Regulation, and More!
Although the above would probably be the major mechanisms by which whey
could help the dieter, there are several secondary effects of whey that may
assist in weight loss. For example, whey's effects on serotonin levels.
Serotonin is probably the most studied neurotransmitter since it has been
found to be involved in a wide range of psychological and biological
functions. Serotonin (also called 5-hydroxytryptamine or 5-HT) is involved
with mood, anxiety, and appetite.
Elevated levels of serotonin can cause relaxation and reduced anxiety. Low
serotonin levels are associated with low mood, increased anxiety (hence the
current popularity of the SSRI drugs such as Prozac and others), and poor
appetite control. This is an extremely abbreviated description of all the
functions serotonin performs in the human body - many of which have yet to
be fully elucidated - but a full explanation is beyond the scope of this
article.
Needless to say, increased brain serotonin levels are associated with an
improved ability of people to cope with stress, whereas a decline in
serotonin activity is associated with depression and anxiety. Elevated
levels of serotonin in the body often result in the relief of depression, as
well as substantial reduction in pain sensitivity, anxiety and stress. It
has also been theorized that a diet-induced increase in tryptophan will
increase brain serotonin levels, while a diet designed for weight loss
(e.g., a diet that reduces calories) may lead to a reduction of brain
serotonin levels due to reduced substrate for production and a reduction in
carbohydrates.
Many people on a reduced calorie intake in an attempt to lose weight find
they are often ill tempered and more anxious. Reductions in serotonin may be
partially to blame here. One recent study (The bovine protein alpha-lactalbumin
increases the plasma ratio of tryptophan to the other large neutral amino
acids, and in vulnerable subjects raises brain serotonin activity, reduces
cortisol concentration, and improves mood under stress. Am J Clin Nutr 2000
Jun;71(6):1536-1544) examined whether alpha-lactalbumin - a major sub
fraction found in whey which has an especially high tryptophan content -
would increase plasma Tryptophan levels as well reduce depression and
cortisol concentrations in subjects under acute stress considered to be
vulnerable to stress.
The researchers examined twenty-nine "highly stress-vulnerable subjects" and
29 "relatively stress-invulnerable" subjects using a double blind,
placebo-controlled study design. The study participants were exposed to
experimental stress after eating a diet enriched with either alpha-lactalbumin
(found in whey) or sodium-caseinate, another milk based protein. They
researchers looked at:
- Diet-induced changes in the plasma Tryptophan and its ratio to other large
neutral amino acids.
- Prolactin levels.
- Changes in mood and pulse rate.
- Cortisol levels (which were assessed before and after the stressor).
Amazingly, the ratio of plasma Tryptophan to the other amino acids tested
was 48% higher after the alpha-lactalbumin diet than after the casein diet!
This was accompanied by a decrease in cortisol levels and higher prolactin
concentration. Perhaps most important and relevant to the average person
reading this article, they found "reduced depressive feelings" when test
subjects were put under stress.
They concluded that the "Consumption of a dietary protein enriched in
tryptophan increased the plasma Trp-LNAA ratio and, in stress-vulnerable
subjects, improved coping ability, probably through alterations in brain
serotonin." This effect was not seen in the sodium-caseinate group.
If other
studies can confirm these findings, whey may turn out to be yet another safe
and effective supplement in the battle against depression and stress, as
well as reduced serotonin levels due to dieting.
Although there is a long list of hormones involved in appetite regulation,
some of which have been mentioned above, serotonin appears to be a key
player in the game. In general, experiments find increased serotonin
availability or activity = reduced food consumption and decreased serotonin
= increase food consumption. If whey can selectively increase serotonin
levels above that of other proteins, it could be very helpful to the dieter.
Other possible advantages whey may confer to the dieter is improved blood
sugar regulation (Frid AH, Nilsson M, Holst JJ, Bjorck IM. Effect of whey on
blood glucose and insulin responses to composite breakfast and lunch meals
in type 2 diabetic subjects. Am J Clin Nutr. 2005 Jul;82(1):69-75.)
which is
yet another key area in controlling appetite and metabolism.
Finally, calcium from dairy products has been found to be associated with a
reduction in bodyweight and fat mass. Calcium is thought to influence energy
metabolism as intracellular calcium regulates fat cell (adipocyte) lipid
metabolism as well as triglyceride storage.
It's been demonstrated in
several studies the superiority of dairy versus non-dairy sources of calcium
for improving body composition, and the whey fraction of dairy maybe the
key.
The mechanism responsible for increased fat loss found with dairy-based
calcium versus nondairy calcium has not is not fully understood but
researchers looking at the issue theorized "... dairy sources of calcium
markedly attenuate weight and fat gain and accelerate fat loss to a greater
degree than do supplemental sources of calcium. This augmented effect of
dairy products relative to supplemental calcium is likely due to additional
bioactive compounds, including the angiotensin-converting enzyme inhibitors
and the rich concentration of branched-chain amino acids in whey, which act
synergistically with calcium to attenuate adiposity."
It appears components in whey - some of which have been mentioned above -
are thought to act synergistically with calcium to improve body composition
(Zemel MB. Role of calcium and dairy products in energy partitioning and
weight management. Am J Clin Nutr. 2004 May;79(5):907S-912S.).
Conclusion
Taken in isolation, none of these studies are so compelling that people
should run out and use whey as some form of weight loss nirvana. However,
taken as a total picture, the bulk of the research seems to conclude that
whey may in fact have some unique effects for weight loss and should be of
great use to the dieter. More studies are clearly needed however.
So what is the practical application of all this information and how does
the dieter put it to good use? Being
the appetite suppressing effects of
whey appear to last approximately 2-3 hours, it would seem best to stagger
the intake throughout the day. For example, breakfast might be 1-2 scoops of
whey and a bowl of oatmeal, and perhaps a few scoops of whey taken between
lunch and dinner.
If whey does what the data suggests it does in the above, that should be the
most effective method for maximizing the effects of whey on food (calorie)
intake on subsequent meals as well as the other metabolic effects covered.
If working out, the schedule may be different, however, and people should
follow the pre and post nutrition recommendations made in my ebook,
Bodybuilding
Revealed.
About the Author - William D. Brink
Will Brink is a columnist, contributing consultant, and writer for various
health/fitness, medical, and bodybuilding publications. His articles
relating to nutrition, supplements, weight loss, exercise and medicine can
be found in such publications as Lets Live, Muscle Media 2000, MuscleMag
International, The Life Extension Magazine, Muscle n Fitness, Inside Karate,
Exercise For Men Only, Body International, Power, Oxygen, Penthouse, Women's
World and The Townsend Letter For Doctors. He is the author of Priming The
Anabolic Environment and Weight Loss Nutrients Revealed. He is the
Consulting Sports Nutrition Editor and a monthly columnist for Physical
magazine and an Editor at Large for Power magazine. Will graduated from
Harvard University with a concentration in the natural sciences, and is a
consultant to major supplement, dairy, and pharmaceutical companies.
He has been co author of several studies relating to sports nutrition and
health found in peer reviewed academic journals, as well as having
commentary published in JAMA. He runs the highly popular web site
BrinkZone.com which is strategically positioned to fulfill the needs and
interests of people with diverse backgrounds and knowledge. The BrinkZone
site has a following with many sports nutrition enthusiasts, athletes,
fitness professionals, scientists, medical doctors, nutritionists, and
interested lay people. William has been invited to lecture on the benefits
of weight training and nutrition at conventions and symposiums around the
U.S. and Canada, and has appeared on numerous radio and television programs.
William has worked with athletes ranging from professional bodybuilders,
golfers, fitness contestants, to police and military personnel.
See Will's ebooks online here:
Bodybuilding Revealed
http://BodybuildingRevealed.com
A complete guide bodybuilding supplements and eating to gain lean muscle.
Fat Loss Revealed
http://FatLossRevealed.com
A review of diet supplements and guide to eating for maximum fat loss.
He can be contacted at:
PO Box 812430
Wellesley MA. 02482
BrinkZone.com
Email: will@brinkzone.com
Additional References of Interest:
Curzon G.Serotonin and appetite.Ann N Y Acad Sci. 1990;600:521-30;
discussion 530-1.
Pierson ME, Comstock JM, Simmons RD, Kaiser F, Julien R, Zongrone J,
Rosamond JD. Synthesis and biological evaluation of potent, selective,
hexapeptide CCK-A agonist anorectic agents. J Med Chem 1997 Dec
19;40(26):4302-7
Blundell JE, King NA. Overconsumption as a cause of weight gain: behavioural-physiological
interactions in the control of food intake (appetite). Ciba Found Symp
1996;201:138-54; discussion 154-8, 188-93
Zittel TT, von Elm B, Teichmann RK, Rabould HE, Becker HD. Cholecystokinin
is partly responsible for reduced food intake and body weight loss after
total gastrectomy in rats. Am J Surg 1995 Feb;169(2):265-70
Smith GP, Gibbs J. Are gut peptides a new class of anorectic agents? Am J
Clin Nutr 1992 Jan;55(1 Suppl):283S-285S
Strader AD, Woods SC. Gastrointestinal hormones and food intake.
Gastroenterology. 2005 Jan;128(1):175-91.
Other whey protein related pages:
What is Whey Protein?
Whey Protein Concentrate
Whey Protein Isolate
Hydrolyzed Whey Protein
Benefits of Whey Protein
Whey Protein Side Effects
Whey Protein Articles
Whey Protein Reviews &
Recommendations