Yo-yo dieting alters genes linked with stress

Nov 30, 2010

Stressed-out mice with a history of dieting ate more high-fat foods than similarly stressed mice not previously on diets, according to a new study in the Dec. 1 issue of The Journal of Neuroscience. The findings suggest that moderate diets change how the brain responds to stress and may make crash dieters more susceptible to weight gain.

In this study, researchers at the University of Pennsylvania led by Tracy Bale, PhD, examined the behavior and of mice on limited diets. After three weeks of fewer calories, the mice lost 10 to 15 percent of their body weight, similar to human diet weight loss.

One in every three Americans is now obese. "Yo-yo dieting" — temporarily losing weight only to regain it, plus more — is a well-known phenomenon. While previous studies show that mice on lifelong calorie-restricted diets live as much as 50 percent longer than their well-fed peers, little is known about the long-term consequences of quick-fix diets.

Bale and her colleagues found the mice had increased levels of the hormone corticosterone and displayed depression-like behavior. The authors also discovered that several genes important in regulating stress and eating had changed. Previous research shows that experiences can alter the form and structure of DNA, an effect known as epigenetics. Even after the mice were fed back to their normal weights, the epigenetic changes remained.

To investigate whether those molecular changes might affect future behavior, the researchers put the mice in stressful situations and monitored how much fatty foods they ate. The previously restricted mice ate more high-fat food than normal mice.

"These results suggest that dieting not only increases stress, making successful dieting more difficult, but that it may actually 'reprogram' how the brain responds to future stress and emotional drives for food," Bale said.

The findings illustrate the underlying mechanisms for why a piece of pizza is so appealing after a stressful day at work. The authors suggest that future weight loss drugs may target these stress-related molecules.

Jeffrey Zigman, MD, PhD, an expert in endocrinology, diabetes, and metabolism at the University of Texas Southwestern Medical Center who was unaffiliated with the study, said the conditions the mice experienced mimic the type of psychosocial stress that people often experience.

"This study highlights the difficult road that human dieters often travel to attain and maintain their weight loss goals," Zigman said. "It also suggests that management of stress during dieting may be key to achieving those goals."

Explore further: Imaging study reveals white-matter deficits in users of codeine-containing cough syrups

More information: jneurosci.org/

Related Stories

Study reports changing to a low-fat diet can induce stress

Apr 18, 2007

Changing one's diet to lose weight is often difficult. There may be physical and psychological effects from a changed diet that reduce the chances for success. With nearly 65% of the adult population currently classified ...

Appetite hormones may predict weight regain after dieting

Sep 09, 2010

Many people have experienced the frustration that comes with regaining weight that was lost from dieting. According to a new study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Me ...

Study shows why weight gain is inevitable

May 09, 2006

Denmark's National Exercise and Nutrition Council says it has found people cannot lose more than 5 percent to 10 percent of their weight through dieting.

Calorie density key to losing weight

Jun 08, 2007

Eating smart, not eating less, may be the key to losing weight. A year-long clinical trial by Penn State researchers shows that diets focusing on foods that are low in calorie density can promote healthy weight loss while ...

Recommended for you

Common infections tied to some stroke risk in kids

8 hours ago

A new study suggests that colds and other minor infections may temporarily increase stroke risk in children. The study found that the risk of stroke was increased only within a three-day period between a ...

Celebrities in 'Ice Bucket Challenge' to fight disease

19 hours ago

Steven Spielberg, Justin Bieber and Bill Gates are among many celebrities pouring buckets of ice water over their heads and donating to fight Lou Gehrig's disease, in a fundraising effort that has gone viral.

Study helps explain why elderly have trouble sleeping

21 hours ago

As people grow older, they often have difficulty falling asleep and staying asleep, and tend to awaken too early in the morning. In individuals with Alzheimer's disease, this common and troubling symptom ...

Targeted brain training may help you multitask better

22 hours ago

The area of the brain involved in multitasking and ways to train it have been identified by a research team at the IUGM Institut universitaire de gériatrie de Montréal and the University of Montreal.

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Ratfish
not rated yet Nov 30, 2010
Doesn't really indicate if the fat:carb:protein ratio was left intact with the caloric restriction.

Even so, a desire to eat fatty food won't make you fat, but a desire to eat carbohydrates will.