Alternative sweeteners are commonly added to protein powder to provide a sweet, palatable taste without using added sugar and increasing calories. These sweeteners work by activating the sweet taste receptors on our tongue but are processed and digested in different ways.
Stevia: Stevia sweeteners come from a specific extract of the stevia plant, known as steviol glycosides. It is a non-nutritive sweetener, meaning it provides no calories. It is about 200-400 times sweeter than table sugar, and it is generally recognized as safe by the FDA with no specific acceptable daily intake (ADI). Stevia is generally well tolerated with little to no side effects. Some people describe the aftertaste of stevia sweeteners as metallic or licorice.
Monk fruit: Monk fruit sweeteners come from lo han guo, or monk fruit plant. The seed and skin of the fruit are crushed to produce juice, then certain sweet-flavored antioxidants called mogrosides are separated from the naturally occurring sugar. It is non-nutritive, 100-250 times sweeter than table sugar, and the FDA has set an ADI of 4 mg per kg of body weight per day. Monk fruit is generally well tolerated with little to no side effects. It is a member of the gourd family and therefore may not be suitable for individuals who have an allergy to pumpkin, squash, cucumber or melon.
Sugar alcohols: Sugar alcohols are a cross between sugar and alcohol molecules, called polyols, that are 25-100% as sweet as table sugar. Some sugar alcohols occur naturally in fruits and vegetables and may also be man-made. There are currently 8 sugar alcohols generally recognized as safe by the FDA, the most commonly used being xylitol, erythritol, mannitol, isomalt, and sorbitol. They are low-calorie sweeteners and can contain between 1.5-3 calories per gram. They are partially digested in the small intestine and then fermented in the large intestine. Sugar alcohols are generally well tolerated in small amounts, up to 10-15 grams per day. Excess sugar alcohol can have a laxative effect, may cause additional gastrointestinal upset like bloating and flatulence, and are not suitable for those following a low-FODMAP diet.
Sucralose: Sucralose is a man-made non-nutritive sweetener that is about 400-700x sweeter than table sugar. It is generally recognized as safe by the FDA and has an ADI of 5 mg per kg of body weight per day. Some research suggests that sucralose may have negative effects on good intestinal bacteria when consumed in excess over long periods of time, but more research needs to be conducted.
Acesulfame Potassium or AcesulfameK: AceK is a man-made non-nutritive sweetener that is about 200 times sweeter than table sugar. It is generally recognized as safe by the FDA with an ADI of 15 mg per kg of body weight per day. It has a slight bitter aftertaste and contributes to daily potassium intake, so it may not be suitable for individuals who need to limit potassium.
Indigestible fibers: Chicory root fiber, inulin, allulose, oligofructose, and others are prebiotic fibers that that are found in some fruits and vegetables. They are not fully digested in the small intestine and instead ferment in the large intestine and colon, feeding good gut bacteria. This can be beneficial for those looking to increase satiety and their dietary fiber intake. They stimulate sweet taste receptors on the tongue and are generally recognized as safe by the FDA. Indigestible fibers may cause gastrointestinal upset such as gas, bloating, and flatulence in large amounts and in sensitive individuals. They are not suitable for those following a low-FODMAP diet. Isomalto-oligosaccharides may also be labeled as a prebiotic indigestible fiber, but new research suggests that they may actually be slow-digesting carbohydrates that fully contribute to caloric intake.