The Science Behind Built Bar

There are currently many nutrition and protein bars available to the consumer. However, to paraphrase a statement made to me by a US Olympic athlete, they all taste about the same, like nut flavored cardboard. He confessed that, regardless of this, he continued to eat such bars. A primary objective in designing Built Bar was to make a bar that was high in protein, low in carbohydrates, had clean ingredients and would actually taste good.

The Basic Nutritional Science of Built Bar
Luke T. Tolley, PhD.
7 July, 2018

Whey Protein Isolate

There are several sources of protein used in protein bars. Three most often are whey, egg whites and products from soy beans. Whey protein isolate was chosen for the bars because it is a complete protein, which means it has all the essential amino acids, it has high digestibility, and a mild taste.

The isolate version we use does not contain casein or lactose, which are the components of milk that some people are allergic to. Very few individuals are sensitive to whey protein isolate. On the negative side, whey protein is more expensive than some other proteins and it is not vegan.

After research, we eliminated soy as a possible protein base. Though it is a complete protein, it has an unpleasant, beany taste that must be masked. Second, and possibly more important, is that soy contains various enzymes that inhibit the digestion of proteins, fats, and carbohydrates. These anti-nutritional enzymes actively prevent you from getting nutrition. Soy protein is flexible in its texture and has a low cost, but the other attributes make it a poor choice for a general protein bar.

We researched using egg white, which is a widely available, complete protein and has a digestibility almost equal to whey protein. A major problem with egg white is that the sources of egg white protein process their powder in different ways. One batch might absorb a certain amount of water while another will absorb much less. It was this inconsistency that led me away from egg whites.

Fiber: Maltodextrin

We wanted to include a source of fiber in the bars to help with the texture and add to the health benefits. The two main categories are soluble and non-soluble fiber, which has to do with whether they dissolve in water. For textural reasons, we use a soluble fiber for ease in making the Built Bar.

A second issue with fiber is the manner in which the body processes it. Some types of fiber are processed by the bacteria in the large intestine in ways that can cause ‘intestinal distress.’ Inulin, for example, is a fiber that is processed by bacteria in the human gut, and generally causes a lot of gas in many individuals. Although there is evidence that, over time, bodies can adjust to inulin in the diet, and subsequently experience less distress, we excluded these types of fiber when designing the protein bar, because you don’t want a customer’s first impression to be a negative one.

There are many different types of maltodextrin. Most are fairly easily digested, so are often used as a ‘slow carb.’ However, ADM/Matsutani came up with a way to process the maltodextrin that would change the ends of the maltodextrin chain enough that neither your body nor the intestinal flora and fauna could start breaking it down. Thus, your body doesn’t actually digest it. This non-digestible, water soluble fiber, called Fibersol, is the source of fiber used in Built Bar. It is readily available and has no negative effects. It is extremely well tolerated, reasonably priced and stable in recipes.


An easy way to make ‘sugar free’ food is to add sugar alcohols. A sugar alcohol is a sugar molecule where the aldehyde at one of the ends of the molecule is replaced by an alcohol. The molecule retains much of its sweetness and physical attributes, but it’s not officially a sugar molecule. In addition, these alcohols are metabolized differently, making it possible for diabetic individuals to ingest these sugar alcohols without experiencing a hyperglycemic (high blood sugar) spike. Sugar alcohols are fairly common in protein bars, with names such as maltitol, sorbitol, xylitol, etc. Though they aren’t sugars, they still have the same caloric value, so the main nutritional benefit is modification of glycemic spikes and the claim for “low sugar.”

A problem with sugar alcohols is that they are digested by the bacteria in the intestines, and can cause ‘intestinal distress.’ For this and other reasons, many people have a negative view of sugar alcohols and try to avoid them.

Erythritol is chemically related to sugar alcohols, but has fewer carbon atoms. This puts it in a unique position. It is a small enough molecule that it passes into the blood stream rather than stay in the intestines, but it’s big enough that the kidneys filter it out. This means that almost all of it is passed out in the urine undigested. Because of this, it effectively has zero calories and yet it’s extremely well tolerated, unlike normal sugar alcohols. It adds sweetness with few side effects, other than a cooling sensation when it dissolves. It’s a naturally occurring compound present in several foods such as pears, watermelon and grapes, and is widely sold in health food stores.

Glycerin is similar to erythritol, but has one less carbon in the molecular chain. It’s a sweet, syrupy liquid that forms the backbone for many important biological molecules. Used with erythritol, it also adds some sweetness while reducing the amount of available water which increases the shelf life of the product. Unlike erythritol, glycerin is digested and so does add nominally to the calorie count.

In addition to supplementing the sweetness of erythritol, these two molecules, erythritol and glycerin, used together form a sweet syrupy liquid that is resistant to crystallization, much like corn syrup. Consequently, the protein mix containing these has a moist texture that is retained longer than use of either of these sweeteners individually would provide.

Built Bar is coated with a high quality dark chocolate which is the source of all the actual sugar in the bar. This chocolate is more expensive than chocolate compounds which are commonly used in nutrition and snack bars. These compounds typically have more carbohydrates and chemicals which we consider undesirable.

This use of this high-quality chocolate could be considered one of the ‘secrets’ of the bar. The finished bar, without its chocolate coating, has a somewhat odd taste. Our perfectly tempered dark chocolate mixes with our naturally flavored protein base to produce a flavor combination reminiscent of high quality candy or dessert. The lingering chocolate aftertaste – the customer’s last impression of the bar – is in sharp contrast to other protein bars which have quite negative aftertastes. Though our choice of chocolate does contribute a small amount of sugar to the bar, we have found that the fiber and protein present greatly decrease the rate of sugar absorption, giving no noticeable blood sugar spike in either Type 1 or Type 2 diabetics.

Use of Gelatin

The gelatin that we use is an animal protein that is used in our protein bar to stabilize the foam structure. Its two major drawbacks are i.) it is non-vegetarian and ii.) it is not halal or kosher. Gelatin is an essential ingredient in our bars and currently there are no good alternatives for the kind of texture that gelatin provides, though some try to use combinations of modified cellulose with locust bean gum with limited success.

Natural Flavoring and Coloring

Customers generally prefer natural flavors and colors. There are particular concerns about artificial colors, which has led to many food manufacturers abandoning them altogether. The protein bar we designed uses only natural flavors and natural colors.


Built Bar has no artificial preservatives. To obtain a reasonable shelf life the bar was designed so that the water availability is low. Microbial and fungal growth requires water. However, if the water availability is sufficiently low, such growth cannot initiate. Though there is significant water in Built Bar, it is tied up with various molecules so it’s not available for the growth of any spoilage organisms. The combination of erythritol and glycerin, noted above, was helpful in attaining this goal.