As blood sugar levels rise in the body when we consume foods high in sugar, the pancreas secrets insulin. In this process, the pancreas is encouraging the cells to soak up this extra glucose ( glucose which isn’t stored in the liver or muscles cells) because free floating glucose is damaging too the body if it’s left in the bloodstream.
Fat cells would usually want to shield the body from the effects of free-floating glucose, so they expand to make room. This causes a higher body fat than normal and can even lead to diabetes and overtime your cells become less sensitive to insulin.
Meaning if you’re pancreas doesn’t secret insulin, than extra glucose would be left in the bloodstream which are damaging to the body.