Obese teens who have trouble responding to insulin tend to have lower levels of a hunger hormone called acyl-ghrelin when fasting, compared to both lean teens and obese teens whose bodies still respond well to insulin.

When obese teens have trouble responding to insulin, their hunger hormone doesn't go down as much after drinking a sugary drink compared to lean teens. But if they're obese and still respond well to insulin, their hormone response is just like that of lean teens.

If a teenager is obese and their body doesn't respond well to insulin, drinking something with a lot of fructose (like sugary soda) won't quiet down the hunger hormone ghrelin as much as it would in an obese teen whose body still responds normally to insulin.

In men with excess belly fat and metabolic issues, a rise in hunger hormone levels was linked to better blood sugar control, higher 'good' cholesterol, and reduced belly fat, even after accounting for how much weight they lost.

People with more belly fat and metabolic issues tend to have lower levels of a hunger hormone called ghrelin, which is linked to higher fat in the liver, more leptin (a fullness hormone), and higher blood pressure.

When obese teens drink a sugary drink with fructose, their hunger hormone doesn't go down like it does in lean teens — meaning their bodies don't signal fullness as well.