The fat cells don’t just get smaller—they get healthier, with better oxygen and less swelling.

Scientists don’t know enough about how the whole mix of small and big fat cells works together to affect health.

In people with obesity, larger fat cells in the subcutaneous layer are more closely linked to insulin resistance in fat tissue than the presence of immune cells, aging cells, or inflammatory molecules, suggesting that fat cell enlargement, not inflammation, is the main factor disrupting fat breakdown.

Making big fat cells smaller by eating less, moving more, or having weight-loss surgery helps fat cells work better and improves your health.

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.

If fat is released from fat stores but not burned for energy, the total amount of fat in the body does not decrease.