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Myth check

A hundred experiments in, aspartame still did not move blood sugar

Twelve randomised trials in one review, 100 controlled experiments in another, and neither could tell aspartame from a dummy drink on glucose or insulin. Finding no effect is not proof there is none.

Aspartame

The worry about a diet cola usually lands on the sweetener: that aspartame does quietly to blood sugar what sugar does openly. Two independent reviews went looking, one pooling 12 randomised trials and the other 100 controlled experiments, and neither could separate it from a dummy drink on glucose or insulin. Both tested the sweetener alone rather than a whole drink, and the newer one rated its own certainty very low on every outcome. The reassurance is real, and narrower than it sounds.

The findings behind this

1–
Metabolic & weightAspartame by itself does not move your blood sugar

Two reviews, one of 12 randomised trials and one of 100 controlled experiments, found no meaningful difference in glucose or insulin against a dummy drink.

★★★Well replicated — this finding’s sources average out to meta-analyses, systematic reviews or high-powered trials.The 2025 review rated its own certainty very low on every outcome, because the experiments differed widely and most carried design weaknesses that could tilt a result either way. The older review's ranges were wide enough to hide a real effect: on body weight it ran from a 1.6kg loss to an 11.6kg gain. Not finding an effect is not the same as ruling one out.Click to keep this openManage weightAspartame

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