Getting fatter may be part of your body's defense against the worst effects of unhealthy eating, suggests a new study.
In recent years, most rich countries, and some poorer ones, have seen a massive rise in so-called "metabolic syndrome", whose symptoms can include insulin resistance, high blood cholesterol and an increased risk of diabetes, heart disease and stroke.
It is well known that the syndrome goes hand in hand with obesity, but exactly how all these conditions are linked is unclear, reports New Scientist.
In an attempt to determine the effects of obesity itself, Roger Unger and Philipp Scherer, both at the University of Texas Southwestern Medical Center in Dallas, reviewed several recent studies of the role of fat cells in humans and mice.
In particular, the pair looked at the fates of people with a genetic condition that means they can't make their own fat cells and mice genetically engineered to have low supplies of these cells and fed a diet that would make normal mice obese.
They found that, despite not being obese, both tend to develop metabolic syndrome earlier on in life than their overweight, overfed counterparts.
This led Unger and Scherer to conclude that obesity protects the body from the effects of overeating by providing somewhere safe to deposit the dietary deluge of fat and sugar, which in excess is toxic to many body tissues.
The study has been published in Trends in Endocrinology and Metabolism.