Drinking sugary drinks with fructose — even when not overweight — might lower a key fullness hormone in women more than drinking the same amount of glucose, which could mess with the brain’s ability to feel full.

For normal-weight women, eating meals sweetened with fructose instead of glucose might make their bodies send weaker 'fullness' signals to the brain, because a key hormone called leptin drops by a third in the first 12 hours after eating.

When normal-weight women eat fructose instead of glucose, it seems to lower the daily swing in their hunger hormone levels by about a quarter, which might mess with their body's natural hunger rhythm.

In normal-weight women, eating fructose instead of the same amount of glucose might make them feel less full and more likely to eat more, because it changes key hunger and fullness hormones in the body.

If normal-weight women drink sugary drinks with fructose instead of glucose—making up 30% of their daily calories—it might cut their insulin response after meals by 65%, because fructose doesn’t trigger insulin like glucose does, which could affect how the body senses fullness or burns energy.

Obese women on a low-calorie diet for 10 weeks show reduced activity of the leptin gene in their fat tissue, which is linked to hunger regulation.