I buy into the idea of the personal fat threshold--a person can be quite sick, but not very fat, but still be beyond their personal capacity for safe sequestration of fat that protects from ectopic--organ, visceral etc.--fat storage. It's fairly robust in animal models that decreasing ability to store fat subcutaneously can lead to these things, and diabetes, and increasing ability to store fat subcutaneously is protective--but it's still going past what can be stored subcutaneously being an issue.