When fat cells are starved of oxygen, they get stressed inside, which may interfere with how they respond to insulin and make metabolic problems worse.

In obese animals, fat cells that don’t get enough oxygen may die or stop storing fat properly, causing more fatty acids to leak into the blood, which can interfere with insulin function.

When fat cells don’t get enough oxygen, they make less of a helpful hormone called adiponectin that helps the body respond to insulin, which might make insulin resistance worse.

In obese animals, fat cells with low oxygen may have fewer and less efficient power plants (mitochondria), making them worse at burning energy and possibly worsening insulin resistance.

When fat tissue doesn't get enough oxygen in obese animals, it starts releasing inflammatory signals that may mess up the body's ability to use insulin properly.

When male rats eat a lot of sugar or fat, their liver and pancreas show signs of cellular stress — like their cells are overwhelmed — and this might be why they develop metabolic problems like obesity or diabetes.