Belly fat really is the worst

Nobody likes being big in the middle, but science has discovered it's linked to stress.
By ERIN ALLDAY
SAN FRANCISCO CHRONICLE
In the world of metaphorical body image, apples are not the fruit of choice.
People with "apple-shaped" bodies -- usually defined by a thick waist or a pot belly -- are more likely to have the most dangerous kind of fat in their abdominal cavities than those with a pear shape, in other words, those who carry their weight in their thighs, hips and butts.
The difference between the two physiques may be a matter of stress.
Recent research has suggested that abdominal fat is related to a hormone released when we're under stress, and now University of California, San Francisco researchers want to study stress-relief techniques and body fat using 50 overweight women.
The goal isn't necessarily to help the women lose weight, but to see if easing stress helps reduce abdominal fat -- and lower the risk of heart disease, stroke and type 2 diabetes.
"We hope they will lose fat in general, but we're not as concerned with whether they lose weight as read on a scale," said Elissa Epel, an assistant professor of psychiatry at UCSF and an expert on the physiological effects of stress. "We are really focusing on improving these women's health through reducing their visceral fat. Where you store the fat is really important."
Deep fat
The fat in a pot belly or a thick waist is not particularly unhealthy, Epel said. But having fat in both areas is a sign of too much visceral fat deep in the abdominal cavity, surrounding internal organs. Doctors don't yet know exactly why visceral fat leads to a greater risk of heart disease and diabetes, but it could have to do with the proximity to the liver and a complex process that promotes atherosclerosis, or hardening of the arteries.
A person doesn't have to be overweight to have too much visceral fat. For example, a woman could be very lean but have a small pot belly that suggests visceral fat lies underneath. Asian Americans in particular are prone to putting on abdominal fat while still looking slender, doctors say. The key is to look at the waist-to-hip ratio -- if the waist is wider than the hips, that could mean trouble.
For years, researchers -- along with pretty much anyone who's ever tried to lose weight -- have known there's a tie between stress and fat. Of course, everyone reacts to stress differently, and the same stress that may drive one person to snack may make someone else lose his or her appetite for reasons that remain a mystery to researchers.
The nasty stuff
Still, many people overeat when they're stressed, and they're more likely to grab a bag of potato chips than baby carrots. But only recently has the connection become better defined and identified as a complex biochemical reaction.
Specifically, cortisol, a hormone that is released when people are under stress, seems to work with insulin to create visceral fat, Epel said. At the same time, cortisol prompts people to crave "comfort foods" -- anything with sugar or fat in it.
At one time in human evolution, such a response to stress would have made sense -- back when "stress" meant drought or famine, among other life-threatening disasters, and sugary, fatty foods would supply energy needed for survival, said Mary Dallman, a professor of physiology in the neuroscience program at UCSF, who has studied the effects of chronic stress.
"A lot of the stress response seems to be about the body being prepared to fight or flight. Your body is doing exactly what it's supposed to do, but our society has gotten a bit ahead of it," Dallman said. "You can work around [the stress response]. You can go for a bike ride, read a book, get away from what's pissing you off. And then after a little quiet time you can [safely] look at grabbing something and putting it into your mouth."
When researchers first began identifying the link between cortisol and food cravings, naturally dieters jumped on a potential weight-loss strategy -- drugs designed to reduce or counteract the cortisol. But it's not that simple, many doctors say.
It all goes back to the idea that a person can be thin and still have too much visceral fat. Cortisol alone doesn't necessarily cause people to gain weight, it just helps them create the wrong kind of fat.
That's why the researchers in the UCSF study aren't promising weight loss to their study participants.
In the study, 50 women will be divided into two groups, one of which will start stress reduction classes right away, the other in six months.