The WHO recently conditionally recommended against using non-sugar sweeteners for weight control. Their stance is that we should be reducing sweetened food/beverage intake in general, rather than trying to find healthier ways to sweeten what we eat.
Aspartame causes weight gain, so abstinence-only isn’t a great analogy.
If you are trying to lose weight, then just use less sugar. That’s actually pretty easy, since artificial sweeteners and sugary drinks desensitize you to sweet stuff.
If you taper off for a week or so, you’ll find that the stuff you were previously drinking is cloyingly sweet.
For instance, reading a starbucks menu makes me shudder. I can’t even drink their non-dairy lattes anymore because they are too sweet.
While that is their stance, it is conditioned on what they seem to consider to be good evidence that using non-sugar sweeteners for weight control does not work (at the level of public health, that is; for individuals, YMMV.)
Liquid chocolate, the kind we drink as a hot beverage in Central and South America, was difficult for me to get used to without any sweet taste.
Nowadays I prefer it that way.
Coffee is a bit more difficult for me.