You are right that my comment as written did not do a good job of explaining what it is about these studies that seems fishy to me. So I thank you for responding to it and making me examine my opinion in more detail.
Someone else already responded to you and provided a much better explanation.
There is always something that rubs me the wrong way about these studies that set out to prove that artificial sweeteners are bad. It's intuitively appealing: it seems too easy that we can just replace sugar with these harmless chemicals and then it tastes mostly the same but without the calories or bad metabolic effects of sugar. But artificial sweeteners have been studied for decades, especially Aspartame, and as far as I know they appear to be harmless, outside of the Gwyneth Paltrow universe. So it seems to me that some people still have an axe to grind with these artificial sweeteners, and try to bend science to their will.
Someone else already responded to you and provided a much better explanation.
There is always something that rubs me the wrong way about these studies that set out to prove that artificial sweeteners are bad. It's intuitively appealing: it seems too easy that we can just replace sugar with these harmless chemicals and then it tastes mostly the same but without the calories or bad metabolic effects of sugar. But artificial sweeteners have been studied for decades, especially Aspartame, and as far as I know they appear to be harmless, outside of the Gwyneth Paltrow universe. So it seems to me that some people still have an axe to grind with these artificial sweeteners, and try to bend science to their will.