If you swallow sugar-free sweeteners in a pill without tasting them, your weight doesn’t change consistently—so it’s not the sweet taste that affects weight, but rather whether you eat fewer calories overall.

Using sugar-free sweeteners doesn’t make you eat more fat or protein than if you used regular sugar or just drank water—so their main job is just to cut down carbs and calories.

If you swap sugary drinks like soda for diet drinks with artificial sweeteners, you might lose weight and reduce fat in your body and liver — especially if you’re overweight or obese.

If you swap sugary foods and drinks for ones with artificial sweeteners, you might lose about 1 kg and eat fewer calories—especially if you cut out a lot of sugar. But this only works if you’re replacing sugar, not just adding sweeteners on top.

Using sugar substitutes like stevia or aspartame doesn’t make you more likely to have bad health effects than eating sugar, drinking water, or taking a fake pill—so they’re probably safe if you’re trying to lose weight.

When you use sugar-free sweeteners instead of sugar, the more sugar you replace, the more weight you tend to lose—this suggests that cutting calories by swapping sugar is why you lose weight.