Is allulose an alternative to sugar on a Keto diet?

Updated: March 15, 2022

Are you following a keto diet, and wondering if allulose is a good choice for you and as an alternative sweetener? The short answer is yes! Allulose can be a good choice on the keto diet – but like any sweetener, it’s important to understand the impact of allulose on health and use it in moderation.

A scoop of allulose on a marble countertop.

What is allulose?

Also known interchangeably as d-psicose or d-allulose, allulose is a monosaccharide that is categorized as a “rare sugar” since it is found very selectively in nature. Food sources of allulose include wheat, jackfruit, maple syrup, molasses, figs, and raisins.

Of course, we’re not advising you to eat any of those on a keto diet – but that just shows that this rare sugar is found naturally in foods. It can be made in bulk by extracting sugars from corn and using an enzymatic process that converts fructose to allulose. At the end of that process, the only sugar left is allulose.

Its structure is molecularly very similar to the monosaccharide fructose (the simple sugar found in fruit). Unlike fructose, however, the body cannot metabolize allulose well resulting in its excretion through our urine (source). As a result, allulose provides a flavor that’s about 70% the sweetness of table sugar while adding negligible calories and net carbs to our daily intake.

Is allulose an artificial sweetener?

No, it is not. Allulose is classified as a rare sugar. Most categorize this as the same as other alternative natural sweeteners, like stevia or monk fruit. Artificial sweeteners, on the other hand, include lab-derived sweeteners like Splenda (sucralose) or Equal (aspartame).

Artificial sweeteners do not provide any calories and may be appealing to those on the keto diet, as they offer sweetness without calories or carbohydrates. However, some (but not all) research has suggested artificial sweeteners may affect sweet cravings or gut bacteria.

Alternative sweeteners, on the other hand, have generally not been linked to these negative consequences. That said, it’s still very early in research on them, and we may find out otherwise in the future. It appears though that natural alternatives like allulose and monk fruit may be better choices though than artificial sweeteners.

Does allulose affect blood sugar?

Since allulose is not well metabolized in the gastrointestinal tract, it has a minimal effect on blood sugar levels.

Research supports this logical conclusion. A double-blind randomized controlled study involving 25 patients concluded that allulose did not affect the post-prandial blood glucose response when added to a glucose tolerance test in doses of 5g and 10g (source).

An earlier study by Lida et al published in 2008 concluded, “An independent administration of 7.5 g D-psicose had no influence on blood glucose or insulin concentration” (source).

How many calories and net carbohydrates are in allulose?

Allulose provides about 0.4 calories per gram. One teaspoon of an allulose sweetener contains about 1 calorie and 4 grams of total carbohydrate.

When calculating allulose carbs, allulose net carbs are subtracted from total carbohydrates because it is not metabolized and therefore, will not cause an increase in blood glucose levels. Because of this, they can be subtracted out to determine net carbs for the keto diet.

How is allulose categorized on food labels?

Allulose used to be included in added and total sugar content on labels, and may still be seen labelled this way.

In 2019, though, the Food & Drug Administration announced they would allow allulose to be excluded from the added sugars and total sugar content on the nutrition facts label.

Dr Susan Mayne, the director of the FDA’s center for food safety and applied nutrition stated, “The latest data suggests that allulose is different from other sugars in that it is not metabolized by the human body in the same way as table sugar. It has fewer calories, produces only negligible increases in blood glucose or insulin levels, and does not promote dental decay” (source).

Some manufacturers will specifically call out the grams of allulose under the carbohydrate section, which makes it easier to calculate out net carbs.

What are the other benefits of allulose?

Emerging research supports several potential benefits of allulose.

Allulose may increase the body’s ability to burn fat. One study including both genders examined the rare sugar’s effect on fat & carbohydrate oxidation. Participants first consumed either allulose or aspartame, then consumed a standardized meal afterwards. The group that consumed the allulose was found to have increased fat oxidation and decreased carbohydrate oxidation in comparison to the control group (source).

Of course, this standardized meal was a carb-containing meal, and as such, does not necessarily extend to the keto diet – but is interesting nonetheless.

Along the same lines, a 2018 preliminary study by Han et al. discovered that allulose intake may be linked to a lower body fat percentage, reduced body fat mass, and overall lower BMI (source).

In addition, a recent study by Chen et al. in rats found improved blood lipid profiles and increased antioxidant activity after four weeks of allulose supplementation (source). Further research is needed to conclude these additional benefits in human consumption.

Is there any reason not to use allulose on a keto diet?

There’s no perfect option for sweeteners – here are a few potential consequences to consider:

1. Cost

Allulose is quite pricey to purchase, averaging about $10 a pound online. If you’re on a budget, there are more wallet-friendly options available for sweetener alternatives.

2. Potential gastrointestinal upset

With all foods, there comes a risk of your body not tolerating it well. According to studies, allulose consumed in large amounts may cause gastrointestinal distress not limited to nausea, abdominal pain, headaches, loss of appetite, and diarrhoea.

The recommended maximum dosage is .4 g/kg body weight in one sitting and an overall total of .9g/kg body weight daily. For a 150 lb person, this is 27g per meal not exceeding 61g in a day (source).

Start out slowly with this rare sugar and see how your body responds to low doses before consuming it regularly.

3. Limited long-term research

Since allulose has only been isolated as a sweetener for about five years, there is limited research on any long term side effects from regular consumption. While it is reassuring that the FDA approves allulose as GRAS (generally recognized as safe), further research is needed to examine long term regular usage.

Should you use allulose on the keto diet?

Even with the concerns above, allulose still makes an excellent alternative sweetener on the keto diet. It can be a safe and natural way to include that pleasant taste without sacrificing ketosis or adding to your net carbohydrate count.

Here are some of the highlights, some of which were mentioned already, as to why allulose can be great for those on the keto diet:

  • Minimal calories
  • Non-glycemic – will not raise blood sugar levels
  • Is considered a natural sweetener source versus chemically manufactured
  • Is comparable in sweetness (about 70% as sweet) as table sugar
  • Has a similar structure and texture as sugar which allows it to be easily baked and swapped out in recipes.
  • Does not cause the cooling sensation found in erythritol

The last one is particularly important for those who are very sensitive to that cooling sensation. If you are, you know that it can be a bummer to make a keto dessert and be met with that weird coldness in your mouth! Allulose is a great alternative because it does not cause anything like this.

What are some ways to use allulose?

You can use allulose as a sweetener in many ways – these may include:

  • Using as a sweetener in berry jams
  • Making keto caramel
  • Sweetening coffee or tea
  • Making homemade keto ice cream
  • Any other delicious keto dessert!

Of note, allulose browns quicker than sugar so cooking times may need to be adjusted if replacing the sugar in your traditional recipes.

Also, since it has about 70% the sweetness of table sugar, your baked goods may not taste as decadent as usual. You may need to adjust the amount of allulose to achieve the same taste.

Where can you buy allulose?

Disclosure: This section contains Amazon affiliate links. As an affiliate, I earn a commission on qualifying purchases.

Allulose can easily be found online. You may also be able to find it in store – for example, our local Stop & Shop carries allulose in the natural section.

Here are a few options for purchasing online:

Final Thoughts

Allulose is a keto-friendly and natural alternative to table sugar and sugar alternatives on the market.

The benefits of allulose include low calorie & low net carbohydrates, lack of impact on blood sugar, and no cooling sensation. Some drawbacks include its high cost and potential gastrointestinal upset if consumed in large quantities. When used in moderation for occasional keto desserts or other uses, though, allulose can serve as an excellent choice for those on a keto diet.

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a bowl full of allulose and a wooden spoon in it, with a text overlay that says should you use allulose on a keto diet?


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