The Whey To Weight Loss!
By Will Brink - Author of: Diet Supplements
Revealed
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,
immunity, etc, can read previous articles by me at the LEF’s web
site: www.lef.org and www.BrinkZone.com).
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 bodyfat, 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.
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 Muscle Building Nutrition* or
advice easily found on the ‘net via the many sports nutrition and
bodybuilding related web sites.
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.
About the Author: Will
Brink is a well known fixture in the bodybuilding and sport
nutrition community and its related publications, and has authored
several books. He can be contacted via his highly popular web
site.
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Diet Supplements Revealed By Will
Brink
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