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2003/03/10, 11:44 AM
"Facts about low carbohydrate foods and protein bars..."
If you've spent longer than a few months on a low-carbohydrate
diet, you'll know that it's very easy to get bored with low
carbohydrate foods. Let's face it — there are only so many
different ways to cook a chicken breast!
Many supplement companies have taken advantage of the popularity
of low-carbohydrate diets by marketing their protein bars as
low carbohydrate foods. However, the debate about glycerol — one
of the ingredients commonly included in protein bars — has left
many people confused about whether protein bars can be
considered as low carbohydrate foods.
Glycerol (also known as "glycerin" or "glycerine") is a
sweet-tasting, syrupy liquid. It's used to sweeten as well as
add a chewy texture to some protein bars.
There's no real reason to be concerned about the glycerol in meal
replacement bars. Compared to other nutrients, glycerol does not
elevate insulin or blood sugar levels. It does, however, contain
calories. Eat enough of it and you'll get fat.
In fact, there may actually be a performance-enhancing benefit
of glycerol. Endurance athletes sometimes use it when they're
exercising for long periods in hot or humid environments. Some
studies show that it can improve performance. But overall,
results have been mixed. What's more, the amount of glycerol
used in these studies is a lot more than you'll find in a
typical protein bar.
In June 2001 the US Food and Drug Administration wrote to the
supplement company EAS (among others) to advise them that one
of their products was misbranded because the label failed to
count glycerol as a carbohydrate.
Glycerol is classed as a carbohydrate mainly by default. It
isn't a protein, because there's no nitrogen in it. Nor does it
contain any fatty acids, so it can't be called fat.
As a result, glycerol is now included in the carbohydrate count
shown on the nutrition label of many protein bars. That's why
it might appear as if your favorite protein bar is higher in
carbohydrate than it was before. However, the only thing that's
really changed is the label.
Because of their convenience, it's easy to become dependent on
protein bars, especially if you can't be bothered to cook or
prepare low carbohydrate foods. However, they do contain
ingredients that can be unhealthy when eaten in excess. That's
why it's important to use protein bars as a supplement to
(rather than a replacement for) meals high in lean protein,
vitamins, minerals and essential fatty acids.
Reference
Magal, M., Webster, M.J., Sistrunk, L.E., Whitehead, M.T., Evans,
R.K., & Boyd, J.C. (2003). Comparison of glycerol and water
hydration regimens on tennis-related performance. Medicine and
Science in Sports and Exercise, 35, 150-156
To view this update on-line, visit:
http://thefactsaboutfitness.com/research/foods.htm
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"Don't follow leaders and watch your parking meters!"
-- Bob Dylan
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