Articles Written by Rehan Jalali

Supplementation Articles

Protein Bars Revealed

Protein bars are certainly everywhere these days.  Walk into any health food, grocery, or even convenient store, and there are boxes upon boxes of these protein fortified snacks.  The problem is there are so many protein bars out there it’s hard to sort through them all.  There seems to be more new bars on the market than web sites going up.  But which protein bars are the best? How can they be beneficial?  What do you need to know before purchasing them? How about low carb protein bars vs. higher carb protein bars? What about the glycerol controversy?

Most of us know that quality nutrition and supplementation is the key to achieving athletic and physique success. It is important to eat 5-7 small meals daily to increase nutrient absorption, enhance metabolic rate, and help stabilize blood sugar (and insulin) levels. High protein meal replacement bars help you stick to this frequent eating program (I sure don't have the time to cook 6 food meals daily!). They can help improve overall nutrition and give you key nutrients your body needs to improve health and physical performance.  They are convenient in that they can be taken with you to work or the gym.  Like meal replacement powders, it is easy to quantify macronutrients in the bar as they are listed on the label.  You know how many calories, protein, etc. you are consuming.  They can also be cost effective.  A typical protein bar costs around 3 bucks, less than a crummy burger and fries. 

Protein bars usually contain protein, carbohydrates, fat, vitamins and minerals, and additional functional ingredients.  High protein/moderate to high carb bars are best suited for athletes and workout fanatics looking to get quality protein and carbs for increased energy.  They are excellent for after a workout to enhance recovery and recuperation and enhance carbohydrate storage (glycogen) in muscle tissue.  Low carb/ high protein bars are good for people looking to maintain lean muscle mass and lose body fat as part of a diet and training program (although I do not advocate the use of protein bars when trying to get “super ripped”!).  The question on everyone’s minds recently has been “how many carbohydrates are actually in my protein bar?” This question has not only been raised by consumers but also the FDA who has now forced manufacturers to label glycerol and other sugar alcohols in protein bars as carbohydrates even though they do not act like carbs in the body.  That is why the nutritional labels of protein bars have changed and you can see that carbohydrate content has shot up drastically with these new regulations. Of course, you’ll also see terms like “net impact” carbs or “unavailable” carbs on the label as well with some sort of fancy chart explaining it all.  Manufacturers are listing these to educate consumers about the type of nutrients in the bars and their little to no impact on blood sugar levels.  The FDA defines glycerol as a carbohydrate by process of elimination.  That is, when a bar is analyzed anything that is not protein, fat, moisture, and ash is considered a carbohydrate.  This philosophy is strongly disagreed upon by supplement manufacturers who contend that since glycerol is only partially absorbed and does not act like a carbohydrate in the body, it should not be listed as such.  Glycerol (also known as glycerin or glycerine) is a colorless, odorless, sweet tasting nutrient. It is technically a trihydroxy alcohol found naturally as the backbone of triglycerides in the body.  It is added to bars to help make them moist and also to sweeten them.  It does not cause any significant blood sugar response when taken as part of protein bar and seems to be eliminated from the body mostly unused.  Glycerol is an interesting compound that has been shown to enhance athletic performance (1) and cause “hyperhydration” when consumed with water (2) (above and beyond that with water alone).  It seems to help keep the body cooler during exercise.  Glycerol does contain 4.32 calories per gram so keep that in mind. 

TIP:  It is very important to drink at least 12-16 ounces of water with protein bars that contain glycerol. First, to help lower the stomach discomfort sometimes associated with protein bars and second to maximize the hydration effects of glycerol.  In fact, when glycerol is ingested without water, it can actually cause dehydration—not good.  Also, eating too many glycerol laden protein bars can cause water retention and bloating in some people.

Most protein bars usually start out with a "proprietary protein blend".  Some bars may have only one protein source such as whey protein isolate but it is preferred to get a protein blend to utilize all the functional benefits of different proteins and help support lean muscle mass. Quality whey protein isolate has benefits including providing intact immunoglobulins to support immune function, providing the highest concentration of BCAA's (branched chain amino acids leucine, isoleucine, and valine which play a key role in the muscle building process-about 25%), it has a high BV (biological value) which means it is readily absorbed and utilized by human muscle tissue, and it may even support IGF-1 levels.  It is very important to look at the processing techniques of different whey proteins as this will determine whether the important microfractions in whey (the compounds that give whey its functional benefits) are still intact and not destroyed.  Look for ion exchange whey isolate (which uses the ion-exchange process where proteins are separated based on their electric charge which is controlled using various chemicals), or ultrafiltered or cross flow microfiltered whey (which both use a very high tech cold manufacturing process that utilizes ceramic filters to remove the fat and lactose and isolates the protein without damaging it).  Whey protein concentrate is a cheaper version of whey protein that is not as pure as whey isolate.  Casein is another milk protein that seems to have a timed release effect as it forms a gel in the gut to slow the transit time of amino acids which may enhance absorption. It has a very high natural glutamine content and most of this glutamine is found in the peptide form for better absorption (due to peptide transport systems in the digestive tract). Glutamine is a very important amino acid that has many benefits including supporting lean muscle mass.  Milk protein isolate contains both whey and casein and it is a decent source for these two proteins. Soy protein isolate has been shown to enhance thyroid hormone output, which can increase metabolic rate to support fat loss. The isoflavones in soy have shown to have numerous health benefits including cholesterol and triglyceride lowering effects. It contains an excellent ratio of glutamine, arginine, and the BCAA's. It is a fairly low priced protein source but can have positive benefits for women mainly but men as well. Egg albumin protein is the "regular old Joe" protein. It boasts a great amino acid profile but does not offer very many functional benefits.  Hydrolyzed protein is also another source of protein found frequently in bars because it is inexpensive.  This protein is heat treated (and pre-digested) and most of the microfractions are destroyed.  However, it does contain peptides which are better absorbed in the body. 

BUYER BEWARE: Another “low quality” ingredient popping up in protein bars is hydrolyzed collagen protein, also known as gelatin.  This is an incomplete protein that is really cheap (I guess that is why it’s in the bars).  If this protein is in the protein blend of a bar, I would be cautious especially if it’s one of the main sources of protein.  Hydrolyzed collagen does have some benefits in terms of joint and skin health but not much for building quality muscle.

Most high protein bars on the market are not baked nowadays so if the raw materials were quality, then the protein microfractions stay intact.  However, the raw material ingredients that make up a bar may have been subjected to heat.  Ask manufacturers of bars to provide you with certificates of analysis for the proteins in the bar (and for the bar itself for that matter) which should give you peace of mind about the quality of the protein you are getting.  Also, bars that contain rolled oats and some granola type bars are baked and the proteins in them lose the microfractions due to baking.  The basic bar making process from a quality manufacturer goes like this: first the main ingredients (including the proteins) are mixed together (manually or using an industrial sized mixer) with water, then the mixture is laid on a table evenly and goes through a “cooling” machine process (the cooling tunnel/extruder), where it is cooled.  Next, the bar is taken out of the cooling machine and coated with a chocolate coating (enrobed). Finally, the bar sheets are cut and ready to be wrapped.  This is of course a very layman’s version of the process.

Protein bars contain carbohydrates as well.  Typically the main source is glycerol (glycerine) especially in “low carb” bars.  Bars loaded with glycerol may cause stomach discomfort in some people so unless you want to hit the porcelain throne throughout the day, again drink plenty of water with these protein bars.  Corn syrup, high fructose corn syrup (dextrose), rice syrup, maltitol, honey (invert sugar), turbinado sugar, sucrose (which is glucose +fructose), crisp rice, and fructose are all used as carbohydrate sources in bars. Fructose is fruit sugar and is added to bars not only to provide a source of carbohydrates but also to sweeten the product as it has a very sweet taste. It is mainly metabolized in the liver and therefore has a lower glycemic index.  Consuming higher amounts of fructose can lower metabolic rate and cause fat storage to occur since the liver can metabolize only a certain amount of fructose.

Protein bars also contain fat. The usual fats found in these bars are partially hydrogenated oils, fractionated vegetable oils, palm kernel oil, and peanut butter. A few bars have added essential fatty acids (EFA’s) but it is very difficult to preserve the quality due to their sensitivity to light, heat and oxygen.  Most of the fat (especially the saturated fat) found in bars is in the chocolate coating.  Saturated fats have been linked to many health problems including cardiovascular disease.  Partially hydrogenated oils produce trans fatty acids (along with other altered fats) during the hydrogenation process.  They are also very detrimental to health and have been known to increase cholesterol and interfere with the livers detoxification system. Hydrogenated oils increase shelf life of products which is usually 9 months to 1 year for most protein bars.  Fractionated oils seem to be better for you.  Fractionation is separating an oil into two or more different triglyceride fractions due to their having different chemical properties.  In other words, it allows weaker oils to be changed into better oils. 

Protein bars contain a blend of vitamins and minerals to support overall health and many chemical processes in the body. Vitamins and minerals are usually ancillary items added to bars but if you have a poor diet, they can help.

USAGE: As a meal replacement or between meal protein boost, consume 1-2 bars daily.  Drink at least 12-16 ounces of water with these bars.  If you have stomach discomfort, eating the bars very slowly and drinking plenty of water can help.  When consuming energy bars, take them one hour before a race or an event.  DO NOT consume protein bars during exercise as they require water for digestion which can pull water out of muscle tissue.  They are also absorbed much slower than a liquid drink or even a sports gel.  Plus of course, the stomach discomfort thing would not be good at this time.

References:

1)     Montner, P., et al., “Pre-exercise glycerol hydration improves cycling endurance time,” Int J Sports Med  (1996) 17.1 : 27-33.

2)     Robergs R, Griffin S, “Glycerol. Biochemistry, pharmacokinetics and clinical and practical applications,” Sports Med (1998) 26.3 : 145-67.

Back to Articles Page

© 2002-2005 Supplement Research Foundation, Inc. All rights reserved.

The content on this site is for informational purposes only and does not replace the advice of a qualified physician.

Please consult a doctor before starting any nutrition, training, and supplementation program.