Health Fitness
The scary truth about soy protein and bodybuilding

The scary truth about soy protein and bodybuilding

Inevitably, there is a myth that soy protein is horrible for bodybuilding and that if you’re serious about working out or building muscle, you’ll stay away. In fact, some sites show ‘studies’ that soy protein and soy products may be harmful to your health. And while it’s true that early claims about the wonders of soy might not be entirely true, there’s also a myth that soy protein is bad for you.

First of all, there is a concept called the Biological Value Scale that was developed to measure the quality of specific proteins. Basically, it rates how efficiently your body will use a given protein source. The higher the BV (biological value), the more amino acids and nitrogen your body retains from the food you eat. In short, it becomes a way to measure the potential for quality muscle growth and strength.

There was a time when egg whites were at the top of the BV scoring around 100. Since then whey proteins have topped the scale around 106-159 BV. This means whey protein is best used for quality muscle growth.

But first a warning!

This does not mean that all you would use is whey protein for all your needs. Many times bodybuilders will use a variety of proteins depending on BV and times of day and if they just finished a workout.

Let me explain… Your protein needs in the morning are different than in the middle of the day and are different again AFTER a workout and different again before bed.

All this means that no protein is the best at any given time. But before I get lost… let me show you the biological value scale in a simple way.

Protein Type :: Biological Value Classification

Whey: 106-159 Egg: 100 Cow’s milk: 91 Fish: 83 Casein: 80 Beef: 80 Chicken: 79 Soy: 74 Wheat gluten: 54 Beans: 49

For all of these reasons, you can and should see soy protein listed below. That just means it’s not the most anabolic protein for optimal muscle growth.

But don’t get me wrong…

This doesn’t mean you shouldn’t eat soy protein if you enjoy it. It simply means that barring religious beliefs or personal preferences, soy would not be the ideal protein source to increase muscle gains. This doesn’t mean you can’t have it or that it’s bad for you.

In fact, let’s continue with a small example.

John Q. Public 13% Body Fat 184 lbs. 160 lbs. LBM (Lean Body Mass)

For simplicity, we’ll just say that for every LB of LBM (pound of lean body mass) John wants to get 1 g of protein.

John should consume 160 g of protein per day.

This is where the myth and some problems come into play! Please read carefully.

If you get a lot of your protein from less than optimal BV sources (beans, soy), you won’t prime your muscles for optimal anabolic growth. John should consume no more than 150 grams of soy protein per day IF he wants to build the most muscle mass and has no personal reason not to use better quality sources.

John also won’t risk losing muscle or wasting his efforts if he eats small amounts of soy protein because he likes it. Having soy in his cereal won’t make a difference.

The myth that soy will cause men to produce estrogen is when ingested in LARGE amounts. Far beyond what any rational person would want to do in the long run.

A bodybuilder who has soy will not feel any difference, he will be less anabolic than someone who does not consume soy at all.

Fact: A long-term metabolic balance study in young men has been published to assess the nutritional quality of an isolated soy protein and beef protein (VR Young, A Wayler, C Garza, FH Steinke, E Murray, WM Rand and NS Scrimshaw) in 1984 by the American Journal of Clinical Nutrition. Am. J. Clinical Nutrition, Jan 1984; 39:8-15.

After 84 days of two groups, one totally isolated from soy protein and the other from beef proteins, it was concluded that:

“Measurements of body cell mass did not reveal any deterioration in the nutritional status of the protein. These observations confirm the prediction, derived from previous short-term nitrogen balance studies, that the nutritional quality of soy protein isolate is high and that this plant protein may serve as the sole source of essential amino acids and nitrogen for protein maintenance in adults.

So let me summarize and review…

Soy is not the most biological source available for optimal anabolic muscle growth. If you had to finish a workout, you might want to eat some high-quality whey protein vs. soy proteins. However, just because it has soy doesn’t mean it’s bad for bodybuilding, unless you get most of your protein from soy products. So it’s not optimal. You would also need to eat enough on a daily basis for the negative effects of soy (specifically targeted at men in this sentence) to manifest.

Copyright 2006 Mark David

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