The Truth About Nutrition Bars
Low carb, net carbs, high protein, complete nutrition, no trans fats, power, balanced�These are just some of the descriptions of all the food bars currently on the market. I recently researched and collected data on the many bars available in my area. The facts may surprise you! (Click to view the chart)
I will begin by explaining the theory behind the current hype about "net carbs" or "effective carbs" or "usable carbs" or "impact carbs."
Carbohydrates can be broken down into monosaccharides, disaccharides, and polysaccharides. Cellulose is a polysaccharide polymer of glucose. It is also called fiber, something which we cannot digest.
Sugar alcohols (polyols) are carbohydrates that are not completely absorbed. Currently, nine polyols have been tested for glycemic index (GI) values:
| Name | GI | Calories/g |
| Maltitol intermediate syrup | 53 (M) | 3 |
| Maltitol regular syrup | 52 (M) | 3 |
| Maltitol high syrup | 48 (M) | 3 |
| Polyglycitol | 39 (M) | 2.8 |
| Maltitol high polymer syrup | 36 (M) | 3 |
| Maltitol | 36 (M) | 2.7 |
| Xylitol | 13 (L) | 3 |
| Isomalt | 9 (L) | 2.1 |
| Sorbitol | 9 (L) | 2.5 |
| Lactitol | 6 (L) | 2 |
| Erythritol | 0 (L) | 0.2 |
| Mannitol | 0 (L) | 1.5 |
(Source:Livesey, op.cit.,pp. 179, 180)
Until recently, it was thought that all polyols reduced the net effect of carbs because of the fact that they were not completely absorbed into the system. However, recent research by Geoffrey Livesey published in Nutrition Research Reviews 2003; 16:163-91 addresses the glycemic index of these polyols. He found that only two, Mannitol and Erythritol have a 0 (zero) GI. The startling evidence revealed that Maltitol syrup has a GI greater than 50.
What exactly is Glycemic Index and why is it so important? The Glycemic Index is how a food ranks based on its immediate effect on blood sugar levels. Carbohydrates break down into glucose. How rapidly they break down into the glucose determines their Glycemic Index. The faster the breakdown, the higher the Glycemic Index. Depending on the source quoted, the Glycemic Index is broken down into 3 or 4 ranges: The University of Sydney's values: Low: 55 or less; Medium: 56-69; High: 70 or more. FormulaZone's values: Low:0-35; Medium:36-70; High:71-100; Very High: Over 100. Personally, I favor FormulaZone's values because it has a more definitive breakdown.
Not all foods have been tested for their Glycemic Index. The list increases all the time as new foods are added.
What this translates into is the fact that high GI foods cause a high insulin response. As a result, when eaten, blood sugar levels will rise significantly and rapidly, causing an insulin response to counteract the surge in blood sugar levels. This in turn causes a dramatic and rapid dip in blood sugar levels (hypoglycemia). These rollercoaster glucose levels wreak havoc in diabetics who need to control their blood sugar levels. It also wreaks havoc in the rest of us, because of the insulin response to the surge in glucose levels. As a result, the brain is deprived of glucose and mental fatigue results. Chronic high levels of insulin can cause fat storage (obesity), the development of heart disease, and has also been linked to breast cancer.
Eating protein releases a hormone called glucagon, which is a fat burning hormone. This hormone releases glucose from stored carbohydrates. It is essential to eat the proper balance of protein and carbohydrate each time you eat.
When I collected the data on the bars, I found that the majority of bars contained maltitol syrup, as well as high fructose syrup
Proponents of net carbs calculate the "impact carbs" by taking the total carb grams and subtracting the sugar alcohols (polyols), glycerine (other carbs) and fiber. This then equates to the "net" or "impact carb" amount. What they fail to realize is that most of the bars are made with Maltitol syrup, which is high glycemic. Instead of sustaining you for 2 to 4 hours and providing you with a steady, even blood sugar level, people have reported feeling hungry soon after eating these bars, and some people have even gained weight when consuming these bars on a regular basis.
Zone followers do not ascribe to the "net carb" theory. We simply look at the total carb value when calculating the balance of carbs:protein:fat. Some Zone followers deduct the dietary fiber from the total carbs and some don't. Fiber is good in that is slows absorption of carbs because it is insoluble, so why deduct the fiber when figuring out the amount of carbs?
In reviewing the data, I also found that some of the bars which claimed to have no trans fats actually did list partially hydrogenated or hydrogenated oils in their ingredients. The amounts were evidently significantly low enough to be within the USDA guidelines as non-reportable, however, trans fat is trans fat and any amount is harmful to your system.
Sugar alcohols (polyols) have been known to cause a number of unpleasant side effects including, diarrhea, bloating and gastrointestinal upset. Some people report polyols are "trigger foods" that cause carb carvings and binges.
In the defense of polyols, I must also list some of the benefits associated with their use. They do not promote tooth decay because they are not initially broken down by enzymes in the mouth. Xylitol interferes wit the growth of some bacteria that may cause ear infections, whereas sugars themselves interfere with white blood cells' ability to destroy bacteria for up to 5 hours. Animal tests conducted suggest that foods containing added fructose or high fructose corn syrup may contribute to the development of retinopathy (damage to the retina of the eyes).
Sugar alcohols should not be confused with artificial sweeteners such as Splenda and Equal (Aspartame). Much research has been conducted on the hazards of Aspartame. This article does not address that topic. Stevia is an herbal all-natural sweetener. Stevia has been reported to have anti-viral qualities, meaning it helps fight off certain viruses.
The accompanying chart (Click to view the chart) is provided for you to examine the nutritional values. It also provides you with the carb:protein:fat balance. The only bar that has been tested to be low glycemic is the new Sears' Hershey's Smart Zone Bars.
Of note is one bar, which totally took me by surprise. I actually thought I had taken down the wrong data, so I went back to the store and re-read the label for accuracy:
CarboRiteFormulaZone's Label Analyzer came up with a balance of 58-3-39, definitely NOT a low carb bar... unless of course, you subtract the sugar alcohols from the total carbs.
"The original Chocolate Bar for Low Carb Dieters"
Peanut Caramel Nougat Bar
The label read as follows:
Calories: 110
Calories from Fat: 50
Total Carbs: 20g
Protein: 1g
Total Fat: 6g
Fiber: less than 1g
Sugar: 0g
Sugar Alcohols: 18g
Net Carbs: 1.1g
Bottom Line: You should read labels carefully and understand the ingredients in the foods you eat. Don't succumb to the current trend and hype about "net carbs". The truth is well stated by Katrina Mather, "Novel carbohydrates are coming out on the market faster than they can be researched as far as their true effect on the body's glycemic level. �.You may also find that slavishly deducting all of a manufacturer's sugar alcohol count from your total carb intake for purposes of weight loss doesn't help much."
Sound advice is to eat good quality, natural, low glycemic products. Use convenience foods as treats, or for the occasional emergency, not as meal replacements on a continual basis.
Glossary
Polyol: Sugar alcohols. Commonly used in "low carb" products because they were thought to not have an impact on blood sugar levels.
Glycemic Index: Also known as GI. The measure of how much, and how quickly, your blood sugar level increases when you eat a carbohydrate. See the related article here: Glycemic Index.
Trans Fats: Chemically altered fats that bind to your cells and cause irreparable damage. See our related article: Trans Fat Deception