Some Dieters Regain Weight

Appetite Hormone Levels May Predict Dieters' Success

Sept. 9, 2010 -- Weight regain is the bane of many a dieter's existence. Often dieters who regain weight after losing it are viewed as failures and judged for their lack of willpower, but new research may put an end to this blame game.

Weight regain may not be solely a willpower issue.  Some people may actually be programmed to gain weight back based on their levels of two key appetite hormones, leptin and ghrelin. The new study appears in an online version of the Journal of Clinical Endocrinology & Metabolism.

"This knowledge could be used as a tool to personalize weight-loss programs that could guarantee success in keeping off the weight," says study author Ana Crujeiras, PhD, of Compejo Hospitalario Universitario de Santiago in Spain, in a news release.

In the new study, 104 obese or overweight men and women ate a low-calorie diet for eight weeks and were followed up with six months later. Their body weight, ghrelin, leptin, and insulin levels were measured before, during, and after the diet. 

Ghrelin is the "go" hormone that tells you when to eat, and leptin is the "stop" hormone that tells you when to stop eating.

On average, study participants dropped about 5% of their body weight while adhering to the low-calorie diet. Six months later, 55 people maintained their weight loss, while 49 regained 10% or more of the weight they had lost. Those individuals with higher leptin and lower ghrelin levels before dieting were more prone to regain weight, the study showed. 

While this may seem counter-intuitive based on the actions of these hormones, the researchers suggest that it may be a matter of some people being resistant to the effects of these hormones.

Their brains may not be getting the fullness or satiety messages that these hormones are delivering. You may have a lot of leptin, but your brain is resistant to its effects; much like people with type 2 diabetes become resistant to the effects of the hormone insulin.

Going forward,  "these hormone levels could be proposed as biomarkers for predicting obesity-treatment outcomes," the researchers conclude. "Our findings may provide endocrinology and nutrition professionals a tool to identify individuals in need of specialized weight-loss programs that first target appetite hormone levels before beginning conventional dietary treatment."

Louis Aronne, MD, founder and director of the Comprehensive Weight Control Program at New York-Presbyterian Hospital/Weill Cornell Medical Center in New York, agrees. "There is something physical going on in people who regain weight," he says.

"Resistance to these hormones is a risk factor for weight regain," he says. Aronne dubs this condition "fullness resistance" and says that your brain is resistant to signals that come from your stomach and intestines telling you that you are full and to stop eating.

View the original article here

Weight Loss Pill

Study Shows RIsks Increase in People Who Already Have Heart Disease

Sept. 1, 2010 – People who take Abbott's weight loss pill Meridia have a higher risk of nonfatal heart attack and stroke, a company-sponsored study shows.

The increased risk was seen only in patients with underlying heart disease. When the FDA learned of the study results last January, Meridia use was restricted to patients without known heart problems.

The European regulatory authorities went further. They banned the drug, known generically as sibutramine and in Europe as Reductil.

Later this month, an FDA expert advisory panel will meet to decide whether Meridia should remain on sale in the U.S.

The researchers reporting the study, W. Philip T. James, MD, DSc, of the London School of Hygiene and Tropical Medicine, and colleagues, including researchers from Abbott, say the drug should stay on the market as long as it isn't sold to people with heart conditions.

The editors of the New England Journal of Medicine disagree. In a strongly worded editorial, they call Meridia "another flawed diet pill." They note that in return for offering a weight loss of under 9 pounds -- less than 5% of the body weight of the overweight participants in the study -- the drug had a one-in-70 chance of causing a heart attack or stroke.

People with underlying heart problems had an even higher one-in-52 risk of heart attack or stroke. And the New England Journal of Medicine editors note that many people who are overweight or obese have undiagnosed heart problems.

Since "the modest weight loss with [Meridia] did not translate into clinical benefit," the editors say, "it is difficult to discern a credible rationale for keeping this medication on the market."

James and colleagues find that among 10,744 overweight or obese people with heart problems or type 2 diabetes, 4.1% of those taking Meridia and 3.2% of those on placebo had nonfatal heart attacks. The nonfatal stroke rate was 2.6% in the Meridia group and 1.9% in the placebo group.

Importantly, they suggest, Meridia did not increase the overall death risk or the risk of death from heart disease and stroke.

Meridia "should continue to be excluded from use in patients with pre-existing cardiovascular disease," James and colleagues conclude.

The Downside of Weight Loss

Weight Loss May Release Pollutants Into Bloodstream, Researchers Say

Sept. 7, 2010 -- There may actually be an unhealthy downside to losing weight.

A new study finds that blood levels of substances known as persistent organic pollutants were higher in people who had lost weight compared to people who maintained or gained weight.

Persistent organic pollutants (POPs) are compounds created by humans in industrial processes and have been linked to a wide range of illnesses, including type 2 diabetes, cancer, dementia, and heart disease. The study appears in the International Journal of Obesity.

Persistent organic pollutants are stored in fat tissues in the body. But when the amount of fat is decreased -- as through weight loss -- they may be released into the bloodstream, where they may enter vital organs, such as the heart and brain.

In the study, researchers compared levels of seven common persistent organic pollutants in 1,099 adults who participated in a national health study in 1999-2002.

They found levels of POPs were significantly higher in adults who had experienced more weight loss. This effect was slightly higher in people who had maintained their weight loss for 10 years or more, compared with people who had sustained it for only one year.

Researchers say the findings may help explain why some studies have suggested, though not proven, that the risk of heart disease, dementia, or death may sometimes increase after weight loss.

However, it's still unclear whether this release of the persistent organic pollutants associated with weight loss or pre-existing obesity-related illnesses are responsible for this increase in risk. Further study will be needed to determine whether this release of persistent organic pollutants is responsible for any negative health effects following weight loss.

View the original article here