'Fat But Happy' Gene Raises Questions About Obesity, Depression

Extra pounds are usually considered a downer, and obesity has been linked to higher rates of depression, mood and anxiety disorders, job discrimination and childhood social isolation. But the relationship between weight and emotional well-being has many mechanisms, and a new study may lend new credence to the notion of "fat but happy."

The FTO gene, a major genetic contributor to obesity thought to cause weight gain by hiking up calorie consumption, is also linked to an eight percent reduction in the risk for depression, according to a study published Tuesday in Molecular Psychiatry.

"The difference of eight percent is modest and it won't make a big difference in the day-to-day care of patients," said David Meyre, an author of the study who is associate professor in clinical epidemiology and biostatistics at the Michael G. DeGroote School of Medicine at McMaster University in Ontario, Canada. "But, we have discovered a novel molecular basis for depression."

This protective effect was found in four different studies and complicates the conventional wisdom, supported by research, that depression increases the risk for obesity and obese people are more likely to become depressed. Meyre started with the hypothesis that both obesity and depression are linked to brain activity, and that obesity genes may be associated with depression -- but found a significant effect in the opposite direction.

Of course, not all obese people have this variant of the FTO gene, and those who do face plenty of depressing health and social problems. But with more than a third of American adults considered obese -- a number that is only expected to swell -- more people may try to embrace the "fat but happy" mindset. Feeling bad about your weight can just make you fatter, after all.