Editor & Fact Checker
Sucralose, also known as Splenda®, is a calorie-free artificial sweetener which is widely used by Americans as a sugar replacement in foods and beverages. It has long been considered to be beneficial in aiding weight loss – and helping combat diabetes.
Sucralose is derived from sucrose – and is actually 650 times sweeter than sugar!
While it is great that sucralose can provide satisfaction from enjoying something sweet without consuming any calories – several studies have linked it to negative health effects.
So, what is sucralose, how does it affect your body - and is it safe for everyday use?
We have taken an insider look and provided you with a science-backed review of sucralose so that you can make an informed decision. Read on to find out everything you need to know about this synthetic sweetener.
What Is Sucralose?
Sucralose is a calorie-free artificial sweetener, and Splenda® is the most widely used sucralose-based sugar alternative. According to the official Splenda website, the benefits of Splenda are that it tastes just like sugar, is great for cooking and baking – and has no effect on blood sugar.
However, several research studies on the effects of sucralose raise questions about the impact on blood sugar (we will look at that in more detail later in the post).
The making of sucralose is a multi-step chemical process which starts with ordinary sugar (sucrose) and involves replacing 3 hydrogen-oxygen groups on the sugar molecule with chlorine atoms . This results in a sweeter than sugar artificial sweetener which is calorie free. The sweetener was discovered by researchers at Queen Elizabeth College, University of London in 1976.
Following thorough testing, sucralose was introduced into the market place around 20 years ago.
Today sucralose is permitted to be used worldwide – and is widely consumed by people who want to reduce their sugar intake. Products sweetened with sucralose include more than 5,000 foods and drinks worldwide, according to the official sucralose website .
While sucralose is calorie-free, Splenda contains glucose and maltodextrin – two carbs. This brings its calorie content up to 3.36 per gram .
Health Concerns Of Sucralose
While sucralose is considered to be safe to use by authorities, it is worth taking an objective look at the scientific evidence – including the studies that may raise questions about its health effects.
Could Sucralose Be Harmful To Your Gut Bacteria?
A study conducted with rats found that that sucralose may have an adverse effect on your gut. The study involved administering Splenda orally to rats for 12 weeks. After the 12-week period, it was found that there was a reduction in beneficial gut bacteria (like bifidobacteria and lactic acid bacteria), but surprisingly the harmful bacteria weren’t as affected . Not only did Splenda have a negative effect on their gut health – but it also did not return to normal levels 12 weeks after the experiment had finished.
Another study conducted with people showed that those who eat non-caloric artificial sweeteners may have different bacteria profiles than those who don’t – but it isn’t clear how these artificial sweeteners cause these changes . It is also worth noting that the effects of artificial sweetener on the body may vary person to person (some studies revealed that only some of the participants experienced changes in their gut microbiome ).
There is, however, a lack of studies with human participants, so more research is needed to investigate how sucralose may affect our gut health.
Does Sucralose Affect Your Blood Sugar and Insulin?
While officially sucralose is said to have very little or no effects on blood sugar and insulin levels – some studies suggest this may actually depend on you as an individual.
A small study carried out with 17 severely obese people who weren’t regular sucralose consumers showed that it actually increased their blood sugar levels by 14 percent, and insulin levels by 20 percent . This indicates that sucralose may have an effect on blood sugar and insulin levels in people who don't regularly consume it.
We could assume that if you are someone who regularly consumes sucralose – your blood sugar levels and insulin levels may not be affected - but if you’re not a regular user, you may potentially experience an increase.
How Does Sucralose Affect Your Weight?
Sucralose, as well as other zero-calorie sweeteners, are often used as a sugar substitute to help people lose or control their weight. However, some studies suggest that artificial sweeteners (including sucralose) may not actually have any significant effect on your weight.
An analysis of randomized controlled trials was conducted to evaluate the relation between low-calorie sweetener and body weight and composition. The review looked at 9 prospective studies – however, findings from observational studies didn't show any association between low-calorie sweeteners and body weight or fat mass – and a very small increase in body mass index (BMI) .
Another review of multiple studies published in the Canadian Medical Association Journal  found that sucralose may be linked to weight gain. The review analyzed 37 artificial sweetener studies to evaluate whether they were successful in aiding weight management. The studies involved more than 400,000 participants over the course of 10 years. Interestingly, no link between artificial sweetener consumption and weight loss was established. Instead, it was found that use over time – by drinking one or more artificially-sweetened beverages a day – resulted in a higher risk of not only obesity and weight gain, but also diabetes and heart disease.
However, it isn’t clear whether artificial sweeteners were responsible for this increased risk – because other factors may have played a role (for example, those who consumed artificial sweeteners may have also consumed more processed food, etc.).
Interestingly, another review of randomized controlled trials showed that artificial sweeteners reduced body weight by an average of 1.7 pounds  – making it difficult to draw a definite conclusion. It appears as though research has shown both – sucralose's ability to reduce and increase BMI, but the effects on body weight are not considered to be major.
Is Sucralose Safe To Use?
Sucralose is considered to be safe by health authorities like FDA – but some studies do suggest that it may have some adverse health effects. Some studies have shown it may raise blood sugar and insulin levels – as well as damage the beneficial bacteria in our gut (although more studies with humans are needed).
Recent studies have also shown that sucralose may be harmful when used for baking. A study into its biological reactions found that when heated, sucralose starts to break down and interact with other ingredients .
Another study found that when heated with glycerol (the backbone of fat molecules) may produce harmful substances which have been linked to increased cancer risk . It might be best to avoid using sucralose for cooking and baking until more research into its effects at high temperatures is available.
Sucralose is a widely used sugar replacement which is low in calories – and is hundreds of times sweeter than sugar.
While it is considered to be safe to use by authorities, several studies have highlighted issues with sucralose and the effect it has on our health – such as raising blood sugar and insulin levels and changing your beneficial gut bacteria. Long-term effects of using sucralose are unclear, and more research is needed.
However, if your body handles it well and you haven’t noticed any negative effects on your gut health or insulin levels, then using sucralose in moderation is most likely fine.
That said, if you’re experiencing issues with your health (particularly gut health) and use sucralose frequently, it may be worth seeing whether it could be a contributing factor.