Some people say they can eat these sugar substitutes without a problem. I learned the hard way that some folks can't.
I had begun to have a carbolite bar now and then, or a small peice of hard candy, sweetened with malitol and sucralose, now and then. It caused me to be hungry, threw off any positive benefits of low-carb, made me tired, halted any weight loss, and caused me to have a fasting blood sugar of 135! I had the A1c test and it showed a borderline high sugar average. I had probably started to eat larger portions of my low carb foods (carb creep) which may have accounted for some of my problems, but the "diet" candy was a serious problem.
Even diet jello, sweetened with aspartame causes me a problem. I haven't tested what Splenda does yet.
I'm glad I learned early that I was headed toward diabetes because I have taken steps to put a halt to that before it gets worse - while I can control it with diet.
I was serious about this diet before but, believe me, I'm really motivated now! I want to keep my legs and vision!