Sweetener affects how body reacts to glucose
Other than sweetening your coffee (or other foods), Splenda may have an impact on how your body processes and reacts to glucose. In a study from Washington University in St. Louis, severely obese people who drank a liquid with Splenda before consuming glucose saw their bodies react with raised insulin levels.
This study focused on 17 severely obese people who did not have diabetes and did not regularly use artificial sweeteners, but who had an average BMI of just over 42 (where 30 is considered obese). Researchers gave the subjects either water or sucralose (Splenda) to drink before consuming glucose, then repeated the tests while switching which group received which drink. This was done to create a "control" group for each participant involved.
When participants drank sucralose, their blood sugar peaked at a higher level than when they drank water alone, but insulin levels also rose 20 percent higher. When the sweetener was served first, the body responded with an enhanced reaction to the glucose that followed.
These results exhibit both positive and negative effects. On the one hand, study participants were still able to produce enough insulin to deal with spiking glucose levels. However, the more routinely the body secretes increased levels of insulin, the more likely it can become resistant to its effects, which can lead to type 2 diabetes.