Do Protein Bars Give You Gas?

What is protein?

The word “protein” is derived from the Greek word “proteios,” or primary, and proteins are an important primary source of nutrition. Proteins contain amino acids, many of which cannot be made by the human body and must be obtained from dietary sources. When eaten, the body breaks down proteins into their amino acid components, and these amino acids are then used to sustain healthy cell growth and function. It’s important to maintain a normal protein balance, as too little or too much protein can cause serious disease.

Where does protein come from?

There are many obvious sources of protein in our diets, including meat, dairy, and fish. However, vegetable-based proteins account for the majority of dietary protein intake worldwide. In the Western diet, wheat (especially in the form of bread) represents the largest source of protein. In other parts of the world, corn or rice are the main protein sources. While pure milled rice and rice flour are not good sources of protein, rice can be processed into byproducts that contain large amounts of protein. There are also more than 200 species of insects that are used as food, providing alternative sources of protein for many people worldwide.

More and more people have realized that protein intake is an important factor in maintaining a healthy lifestyle, and because of this there has been an increased worldwide demand for protein-rich foods. Plant-based protein has surged in popularity in recent years, and many people also consume protein bars on a regular basis.

What are protein bars?

Protein bars are typically made from protein powder, sugar syrup, and fat. Because of consumer demand for healthier, low-calorie products, many protein bar formulations include sugar alcohols as sweeteners instead of traditional sugar sources such as fructose, glucose, or sucrose. Sugar alcohols, including xylitol, sorbitol, mannitol, and erythritol, are naturally present in small amounts in fruits and vegetables and have varying levels of sweetness. These compounds have lower nutritional value and caloric content than traditional sugars because they are poorly absorbed from the human gastrointestinal system and are instead broken down within the intestines by gut bacteria. Because of this, sugar alcohols have only minor effects on blood sugar and insulin levels. In addition, some sugar alcohols have unique properties that distinguish them from traditional sugars. For example, xylitol prevents the growth of oral bacteria that contribute to dental plaque and cavities. For this reason, xylitol is often found as an ingredient in “sugar-free” chewing gums and candies. However, when eaten by dogs, xylitol causes severe poisoning, including low blood sugar levels and liver disease.

What are the side effects of sugar alcohols?

There are some adverse effects associated with the consumption of sugar alcohols. Some scientists believe that the intestinal breakdown of sugar alcohols by gut bacteria adversely affects the intestinal microbiome and might contribute to the development of obesity. Because they are poorly digestible, sugar alcohols can also cause gastrointestinal side effects, including abdominal pain, bloating, and gas. Sugar alcohols can have a laxative-like effect on the intestines and cause diarrhea. These undesirable gastrointestinal effects typically occur after consumption of high doses of sugar alcohols, but some people are more sensitive to the laxative effects and can develop them after consumption of small quantities. The occurrence of gastrointestinal side effects also depends on other factors, including body weight, whether the consumed product was liquid or solid, and the type of sugar alcohol. Erythritol undergoes more intestinal absorption than other sugar alcohols, leading to fewer side effects when compared to the others.

For questions about unexpected or undesirable effects after exposure to sugar alcohols, including xylitol and sorbitol, contact poison control for expert advice. Get an immediate personalized recommendation online or call 1-800-222-1222. Both options are free, confidential, and available 24 hours a day.

Kelly Johnson-Arbor, MD
Medical Toxicologist