I cannot consume aspartame. I suspect there are others. One dose of aspartame gives me an ocular migraine within 24 hours. For me, that's not right, and my assumption is that whatever the mechanism is that causes this, I don't want to mess with it. I've tried other sweeteners and when pepsi and coke used sucralose (Splenda) for a short period of time, I thought I had found a diet drink that I could drink occasionally. Over time, I decided, whether it comes with other health consequences or not, I needed to avoid anything sweet, as being a strict low carber eliminates any sweet cravings over time. Like others in this camp, I no longer have any desire for sweet stuff. When I first started low carb, I busied myself by finding safe substitutes for the sweet stuff I ate, but realized that my addiction to anything sweet could be managed and would fade over time. It did. This is obviously an N=1 experience and realizing that many do fine with AS and NS for when they want something sweet, the conclusion here is always based on a personal tolerance, never a general association.