Splenda is commonly used as a sugar substitute in both cooking and baking. It's also added to thousands of food products worldwide.
Sucralose is calorie-free, but Splenda also contains the carbs dextrose and maltodextrin, which brings the calorie content up to 3.36 calories per gram (1). However, the total calories and carbs contributed by Splenda are negligible because you only need to use tiny amounts each time. Sucralose is actually 400-700 times sweeter than sugar, and does not have a bitter aftertaste like many other popular sweeteners (2, 3).
Sucralose Effect on Blood Sugar and Insulin
Sucralose is said to have little or no effects on blood sugar and insulin levels.
However, this may depend on you as an individual and whether you're used to consuming artificial sweeteners. One small study in 17 severely obese people who did not regularly consume artificial sweeteners reported that sucralose elevated blood sugar levels by 14%, and insulin levels by 20% (4).
So, if you don't consume sucralose on a regular basis, it's possible that you may experience some changes to your blood sugar and insulin levels.
If you're used to consuming sucralose, then it probably won't have any effect.