Low-Calorie Sweeteners: Types, Safety, and How They Affect Weight and Blood Sugar

Summary

Sweetness historically helped identify energy dense, safe foods, but today added sugars in foods and drinks can contribute excess calories. Low calorie sweeteners offer sweet taste with far fewer calories and have been shown in randomized controlled trials to support modest weight loss when used to replace full calorie foods and beverages, provided total calories from other sources are not increased. This video explains how different sweeteners work, including aspartame, sucralose, acesulfame potassium, stevia, and monk fruit glycosides, and why they are far sweeter than sugar so only tiny amounts are needed. It also covers how some are plant derived and others are synthetic, their digestion and excretion, typical blending in products, and the safety framework created to ensure daily intake remains well within safe limits.

Overview and context

The video explains how sweetness originally signaled energy dense foods that were safe to eat, a crucial cue during times of food scarcity. In the modern food environment, sweetness often comes from added sugars that contribute significant calories. Replacing full calorie foods and drinks with low calorie sweetened versions can lead to modest but meaningful weight loss, as long as people do not compensate by consuming extra calories elsewhere. Low calorie sweeteners also do not raise blood glucose or insulin levels, which can help people with diabetes manage blood sugar and reduce daily sugar intake.

Categories and origins

Some low and no calorie sweeteners come from plants, such as stevia and monk fruit, while others are manmade, like aspartame, sucralose, and acesulfame potassium. All of them are sweeter than sugar, meaning only tiny amounts are required to achieve the same level of sweetness. In many tabletop packets, sugar substitutes are blended with carbohydrates such as dextrose or maltodextrin, or with sugar alcohols like erythritol, to create a similar volume to a packet of sugar. This is why packets of low calorie sweeteners and sugar look alike in size.

Individual sweeteners and their metabolism

Aspartame is about 200 times sweeter than sugar and is composed of aspartic acid, phenylalanine, and methanol. It is rapidly broken down in the small intestine into these components, all of which occur naturally in higher quantities in other foods. It provides calories per gram like sugar, but because it is so sweet only a tiny amount is needed, so it does not contribute substantially to daily calories.

Sucralose is about 600 times sweeter than sugar. It is derived from table sugar by substituting chlorine for three hydroxyl groups, which prevents digestive enzymes from fully breaking it down. Consequently, roughly 85% of sucralose passes through the body unabsorbed, with the small portion absorbed being quickly excreted in urine. It contributes no calories at typical consumption levels.

Acesulfame potassium (ACK) is about 200 times sweeter than sugar. It is usually used in combination with other sweeteners. ACK is absorbed in the small intestine but is not broken down; it is excreted in urine and provides virtually no calories, and its potassium content is small because only tiny amounts are found in foods and beverages.

Stevia glycosides come from the stevia plant and are about 200 times sweeter than sugar. They are not absorbed intact in the upper gastrointestinal tract. In the colon, the gut microbiota can cleave glucose moieties from the steviol backbone, and the remaining backbone is absorbed, metabolized by the liver, and excreted in urine.

Monk fruit glycosides come from the monk fruit and are about 250 times sweeter than sugar. The mogrosides are glycosides that undergo only minimal systemic absorption. The glycosidic attachments can be cleaved by gut microbiota, with the resulting backbones excreted from the body.

Safety framework and intake guidelines

All low calorie sweeteners have been studied to determine their safety and establish a daily intake level known as the Acceptable Daily Intake, or ADI. The ADI is derived from animal studies to identify a no observed adverse effect level, NOAEL, and is divided by 100 to create a conservative safety threshold. In practice, most people consume far less than the ADI, even those with a strong sweet tooth.

Takeaways

Low calorie sweeteners offer a way to reduce calories from sugar without sacrificing sweetness. Each sweetener has a distinct chemical structure and metabolic pathway, and all have demonstrated safety within typical consumption levels. They can support weight management and blood sugar control when used thoughtfully as part of a balanced diet.