Fresca was better with cyclamates. 
Then they started using saccharin instead. Ah, for the Fresca of my youth! 
I know celiacs who say “allergic to wheat” and beam at me when I say “oh, celiac?” “yes!” They’re used to people not having the foggiest what “celiac” means but being respectful of “allergic to [insert food here]”. Similar for lactose intolerant folk: if I try to explain “lactose intolerant”, most people just won’t grok it and keep asking “but why?” and offering solutions, but if I say “allergic to something called lactose, which is in regular milk but not in lactofree”, then all is well in their universe and I can go on drinking my quasi-milky goodness.
My BMI is 19- I drink don’t drink diet sodas (because I don’t like the taste) and have 2 sugars in my coffee. I also drink whole milk and eat full fat cheese, yogurts and butter.
Since I don’t snack between meals and drink maybe 1 can of coke a week, and 2 coffees a day, I reckon I can afford the calories.
This is not a “ha ha I can’t eat everything I want and stay skinny” thing- I eat whatever I want to eat, I just don’t eat much of it, or know that I’ll have to cut back somewhere else. Big lunch= small dinner. Pudding with dinner=smaller portion of main course.
I find that aspertame can make an already existing headache worse. That’s all, though. I wouldn’t call it allergic.
I will say that sucralose (Splenda) is the only sweetener that I like the taste of, and even it starts tasting bad if I use it too much–it lacks the bite of real sugar.
I am very fat and have known many fat people, and I’ve never heard ANYONE claim to be allergic to artificial sweeteners. In fact, despite my girth, I almost exclusively drink diet sodas when I have soda at all, because they taste just fine, and the sugar is “invisible” calories.
Joe
I am fat and not allergic to any artificial sweeteners.
That said, drinks (and gum, for that matter) with acesulfame potassium (ace-K) like Coke Zero often give me a raging headache. So, while I will kindly refuse your offer of a Coke Zero, I will gladly drink Diet Dr. Pepper.
I don’t drink soft drinks, regular or diet. I am slightly overweight and actually allergic to aspartame.
It’s a PITA. Luckily it’s pretty easy to avoid.
My doctor diagnosed me in high school (I’m 37 now). When exposed to aspartame, I end up with hives all over my face and neck and have a slightly difficult time breathing.