People with obesity tend to have higher insulin levels when fasting and their blood sugar spikes more after eating carbs, but their bodies still use the sugar from those carbs just like lean people do.

Even though obese people have higher blood sugar after eating carbs, their bodies still break down and use the sugar from those carbs just as well as lean people do.

After eating just three days of mostly fatty food instead of carbs, healthy young men had higher blood sugar spikes when they drank a sugary drink, meaning their bodies handled sugar less efficiently.

If you eat before working out, your blood sugar and insulin levels spike more during exercise than if you work out on an empty stomach.

If you're overweight around the middle and eat a meal full of carbs, your blood sugar and insulin spike more than if you ate a meal with lots of butter or olive oil—but your body doesn’t make as much insulin for how much sugar is in your blood.

When healthy people eat a carb-rich meal, their muscles get more blood flow and their blood vessels relax, even though their body also sends signals to tighten blood vessels—this might help their body absorb sugar from the meal better.