We are now in what feels like the 347th year of the fastidiously vilified "obesity epidemic.” Health officials repeatedly warn that everywhere in the world people are gaining too much weight and putting themselves at risk of diabetes, high blood pressure, heart disease and other obesity-linked illnesses, not to mention taking up more than their fair share of subway seats.

It’s easy to fear and despise body fat and to see it as an unnatural, inert, pointless counterpoint to things fabulous.

Yet fat tissue is not the problem here, and to castigate fat for getting too big and to blame it for high blood pressure or a wheezing heart is like a heavy drinker blaming the liver for turning cirrhotic.

In fact, like the drinker’s liver, fat tissue also has our best interests at heart.

“Obesity is not due to any defect in adipose tissue per se; it’s an issue of energy balance, where the excess energy is stored in adipose tissue,” said Bruce M Spiegelman of the Dana-Farber Cancer Institute in Boston.

“If you had no fat cells, no adipose tissue, you’d still be out of energy balance, and you’d put the excess energy somewhere else,” he said, at which point really bad things can happen. Consider the lipodystrophy diseases, rare metabolic disorders in which the body lacks fat tissue and instead dumps its energy overruns in that jack-of-all-organs, the liver, causing extreme liver swelling, liver failure and sometimes even death.

“Some adipose tissue is a good thing,” said Barbara Kahn, chief of the endocrinology, diabetes and metabolism division at Beth Israel Deaconess Medical Center, at Harvard.

... contd.