I've tried numerous meal replacement shakes over the years. I like a few, don't like most. It doesn't seem to matter how much sweetener or flavoring they add, if it tastes like Little Friskies I can't swallow it. I've found that whey tastes best to me, although there are a few that have soy protein that aren't totally disgusting and some that are made of pea protein that I really don't care much for but could live with if I had to. I've actually grown to like one that has a mix of pea, rice, and chlorella, and would say if you are vegan it is worth looking at (comment below if you want to know where to get it).
Turns out there is a difference between whey and soy as far as our bodies are concerned; muscles prefer to be made from whey protein, not soy protein. Lately I've been using one from Isagenix that comes from whey made by grass-fed cows in New Zealand - TRULY happy cows! I really like this one and find myself looking forward to the next time I can have it. If you've looked at Isagenix in the past, things have changed, so look again. Here's a story about some research that shows why
According to a new study, soy protein does not compare to whey protein when it comes to muscle growth.
Need another reason to choose whey protein over soy when trying to
preserve and build lean muscle mass? A new study (1) from McMaster
University in Canada found that when compared to whey protein, ingesting
soy protein after a workout or at rest does about as much as plain
water for muscle protein synthesis.
The study randomized 30 elderly men into three treatment groups to
test the effects of ingesting 0 grams of protein, 20 grams of soy
protein, or 40 grams of soy protein at rest and after a bout of
resistance exercise. These effects were then compared to previous
responses in similar aged men who had ingested 20 grams or 40 grams of
whey protein at rest and after resistance exercise.
Results showed that rates of muscle protein synthesis for ingesting
20 grams of soy protein were no different than ingesting 0 grams of
protein. The higher dose of soy protein, 40 grams, only modestly
increased rates of muscle protein synthesis after exercise in comparison
to people who consumed no protein.
In contrast, previous data from the study authors showed that
consuming whey protein at rest and after exercise has shown to induce
muscle protein synthesis whether in a dose of 20 or 40 grams, with the
larger dose having a greater effect.
“We report that soy protein isolate is relatively ineffective in its
capacity to stimulate MPS [muscle protein synthesis] in the elderly when
compared to whey protein,” wrote the researchers.
The findings from this study should speak to aging adults who are
looking to avoid the muscle-wasting effects of sarcopenia, as protein
source and dose are showing more and more to be critical in avoiding
age-related muscle loss. Even though both whey and soy proteins are
considered high-quality proteins based on the digestibility of their
amino acids, and both are considered ‘fast’ proteins because they cause a
rapid increase in amino acids available to be utilized by muscles, the
actual digestion and muscle-building potential of whey and soy protein
are quite different.
For one, whey protein has a higher percentage of the amino acid
leucine, which has shown to be the “master” amino acid for the synthesis
of muscle. What’s more, the current study found that a greater
proportion of soy’s amino acids—including leucine—are diverted towards
oxidation, making them unavailable for muscle synthesis. This goes along
with the findings of prior studies (2, 3) that revealed the amino acids
contained in soy protein are metabolized in the body by gut proteins.
The amino acids in whey protein, on the other hand, are partitioned for
use by skeletal muscle tissue—leading to greater rates of muscle
synthesis. To top it off, soy protein products do not usually exceed 20
grams per serving and research is showing that we need closer to 30
grams of protein per meal (4).
Whey protein is not just for older adults looking to preserve their
muscles. Whey protein has shown to be superior to soy in increasing
muscle protein synthesis after exercise in young adults too (5).
Whether young or old, Isagenix has the whey protein needed for
maximal muscle growth and maintenance for everyone. Maintain muscle mass
by enjoying an IsaLean Shake with 24 grams of protein or an IsaLean Bar with 18 grams of protein. Older adults or those looking to maximize their muscle growth may also benefit from having IsaLean Pro with a supercharged dose of 35 grams protein.
There are many choices to consider when looking for the right protein
supplement in your diet. Rest assured that at Isagenix we look to the
science to bring you the right protein in the right amounts to maintain,
repair, and build muscle.
Yang Y, Churchward-Venne TA, Burd NA, Breen L, Tarnopolsky MA,
Phillips SM. Myofibrillar protein synthesis following ingestion of soy
protein isolate at rest and after resistance exercise in elderly men. Nutr Metab (Lond) 2012;9:57. doi: 10.1186/1743-7075-9-57
Bos C, Metges CC, Gaudichon C et al. Postprandial kinetics of
dietary amino acids are the main determinant of their metabolism after
soy or milk protein ingestion in humans. J Nutr 2003;133:1308-15.
Fouillet H, Mariotti F, Gaudichon C, Bos C, Tome D. Peripheral and
splanchnic metabolism of dietary nitrogen are differently affected by
the protein source in humans as assessed by compartmental modeling. J Nutr 2002;132:125-33.
Symons TB, Sheffield-Moore M, Wolfe RR, Paddon-Jones D. A moderate
serving of high-quality protein maximally stimulates skeletal muscle
protein synthesis in young and elderly subjects. J Am Diet Assoc 2009;109:1582-6.
Tang JE, Moore DR, Kujbida GW, Tarnopolsky MA, Phillips SM.
Ingestion of whey hydrolysate, casein, or soy protein isolate: effects
on mixed muscle protein synthesis at rest and following resistance
exercise in young men. J Appl Physiol 2009;107:987-92.doi: 10.1152/japplphysiol.00076.2009