If you can find a way to make the drinks palatable without artificial sweeteners, then that is good advice. Sweeteners like aspartame, and saccharin have been linked to causing problems in the past. Others like sorbitol, xylitol, erithritol can trigger insulin rushes, and can spike blood sugars. Others like Malitol, Maltodextrin and similar polysacharrides cause glucometers to misread. The ones that some use such as sucralose are better for baking and cooking, and are considered generally safe to use.
Stevia is a natural sweetener, but beware that the commercial form is often cut with other sweeteners to improve the bitter taste it has on its own. Dextrose or maltodextrin are sometimes used, which defeats the object.
Fructose is sometimes used since it is not metabolised in the same way as sugar, but it has been associated with exacerbating Type 2 and / or NAFLD, OK in natural fruit, but not as an additive.