Obesity is not widely considered a protective mechanism. Quite the opposite. It’s usually considered one of the causal factors of the metabolic syndrome and insulin resistance.
I think obesity is a marker of disease, but ultimately it serves to protect the body from the effects of hyperinsulinemia. Let me explain:
Gina Kolata, a journalist at the New York Times wrote a recent interesting article called ‘Skinny and 119 Pounds but with the health Hallmarks of Obesity‘. She describes Claire Johnson, a patient with a rare case of lipodystrophy, a genetic disorder characterized by the lack of fat.
She was skinny but always ravenously hungry. She could never get fat, because she lacked fat cells.