Typically, sparkling waters with natural flavors are fine. Most of us drink flavored sparkling waters with no problem. Of course, do check the ingredients list carefully, and re-check often (companies reformulate products all the time), to MAKE SURE there are no sweeteners listed. Also note that the term “natural flavors” can sometimes mask hidden sweeteners, so proceed with caution. If you find your consumption escalating, or notice that you’re relying on it like a crutch, best to let it go.