Allulose is a low-carb sweetener that doesn’t count towards your sugar intake. This naturally-occurring sugar substitute doesn’t raise your blood sugar levels, making it an option for low-carb diets. But is allulose keto-friendly?
It has health benefits you won’t find in other natural sweeteners like stevia, monk fruit sweetener, and erythritol. It can improve your insulin sensitivity, help burn fat, and may protect your liver.
Discover the remarkable properties of allulose, how to use it, how much is safe to consume, and when it’s right to make the allulose-keto connection.
Allulose is a naturally-occurring monosaccharide (simple sugar). It’s about 70% as sweet as table sugar but contributes 90-95% fewer calories[*].
Other names for allulose include d-allulose, psicose, and d-psicose. It’s found in small amounts along with other carbs in fruits like figs, jackfruit, and raisins, as well as in other agricultural products. Structurally, allulose is almost identical to fructose, but it has a “flipped” hydroxyl (OH) group. And unlike fructose, allulose keeps your blood sugar stable.
According to the FDA, allulose is no longer counted towards total or added sugars for labeling purposes[*]. That’s because this sweetener doesn’t act like sugar in your body.
Allulose is generally recognized as safe (GRAS) by the FDA. Like other sugar-free sweeteners, it was found to have a glycemic index of zero, not raising blood glucose levels[*].
A big hint that allulose isn’t a typical sugar or carbohydrate comes from the FDA labeling decision. Essentially, the FDA is acknowledging that allulose doesn’t raise your blood sugar. In fact, it doesn’t behave like a typical sugar inside your body.
In a randomized study of healthy people, 5-7.5 grams of allulose consumed before a 75-gram sugary drink resulted in lower blood sugar and insulin levels[*].
During a separate clinical study, a mixed group of people — some of whom had relatively mild type 2 diabetes — consumed 5 grams of allulose at meals three times daily[*]. Researchers discovered that the participants had lower blood glucose and that allulose was safe and didn’t cause any side effects. Other studies in animals and people have confirmed its blood-sugar-lowering effects[*][*].
According to a rat study, allulose may even help protect pancreatic beta-cells, where insulin is made. Since untreated type 2 diabetes leads to beta-cell death, allulose might help slow or prevent the progression of diabetes[*].
In a study of healthy men and women, a 5-gram dose of allulose followed by a meal resulted in approximately 10% greater fat-burning compared to the control group[*]. The same study also found that their glucose levels were lower and free fatty acid levels higher, which is favorable for burning fat.
A separate 12-week study of overweight people found that daily allulose prevented weight gain, reduced their waist circumference, and caused weight loss[*]. Another large trial conducted in Korea found similar results[*].
An experiment in mice demonstrated that the sugar suppresses appetite and causes the release of GLP-1 (glucagon-like peptide 1)[*]. GLP-1 enhances insulin release, improves insulin sensitivity, and reduces hunger[*][*].
Allulose can also modify gene expression to reduce fat accumulation, promote fat burning, and increase antioxidant levels (in rats)[*].
These unusual properties mean that allulose may be a helpful tool for preventing and even reversing obesity[*].
Because it increases antioxidant levels and enhances your body’s metabolism of sugar and fat, allulose may also prevent inflammation and related issues in your liver.
In a study of mice, allulose supplementation reduced fat mass and improved fatty liver associated with obesity[*]. Another study found that it reduced the activity of enzymes that contribute to liver fat storage[*].
Finally, a separate study found that allulose increased liver insulin sensitivity and glycogen content[*].
From the evidence, small quantities of allulose appear to be very safe.
For example, a 2010 clinical study found that no abnormal effects or medical issues occurred in people who consumed 15 grams of allulose per day for 12 weeks[*].
Possible Side Effects
If you consume too much allulose, you might get nauseated or have diarrhea[*]. The upper limit for a single dose is 0.4 grams per kilogram of body weight — that’s about 27 grams, or approximately two tablespoons, for a 150-pound person at a sitting[*].
Sugar alternatives like allulose can have unpredictable effects on gut bacteria. The daily upper limit to avoid gastrointestinal side effects is 0.9 grams per kilogram of body weight, or 61 grams per day for a 150-pound person[*].
Unlike artificial sweeteners (like Splenda) and sugar alcohols (like xylitol), there haven’t been any studies on allulose’s impact on the microbiome. While there’s nothing to suggest it’s harmful, you may want to pay extra attention to how your body responds if you’re prone to gut issues, bloating, or related problems.
If you’re on the ketogenic diet, low to moderate doses of the sweetener are extremely unlikely to kick you out of ketosis.
That’s because your body absorbs and excretes allulose without ever metabolizing it as sugar. It also seems to enhance fat oxidation and decrease carbohydrate oxidation, both of which are beneficial for ketosis.
Is Allulose Keto-Friendly?
For a simple sugar, allulose is as keto as it gets.
It enhances fat oxidation, lowers your blood sugar, may improve your insulin sensitivity, and could even result in weight loss. Plus, allulose is also very unlikely to kick you out of ketosis, unlike other sugars like fructose.
Because your body only absorbs a tenth to a twentieth of the calories compared to regular sugar, most of the downsides of eating sugar don’t apply.
That said, any type of sweet treat or rewarding yourself with food can perpetuate addictive eating patterns, even if you use sugar replacements.
If you’re just starting a keto diet, the best strategy is to go a few months without treats to reset your preferences, then enjoy them occasionally.
Once you get to a place where you can have a healthy relationship with sweet-tasting foods, allulose keto treats are a fantastic choice. For sweet keto-friendly ideas, check out the dessert recipe section on this website.