Sweetener in coffee?

Only you can say if it spikes you and that's if your testing yourself before and after.
Harmful or not? Literature seems to suggest not...
If you love coffee, try it without sugar/sweetener... and if that doesn't work, a shot of double cream to take the edge off.
I used to be 2-3 sugars and cream in my coffee...
just black for the last three years and wonder why I wasted the previous 30 years of coffee...