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Despite a general belief among physicians that extreme obesity is too difficult to treat, except with bariatric surgery, researchers at the Pennington Biomedical Research Center have learned a substantial proportion of individuals with extreme obesity can lose 10-percent or more of their body weight through medical treatment that does not include surgery.

10% Loss Improves Risk Factors and Health

Furthermore, even though those individuals are still obese, they have improvements in risk factors and other health markers.

Weight Loss Surgery Not Often Affordable or Reimbursed by Insurance

"This is important, because surgery is not often affordable or reimbursed by insurance," said leading scientist Dr. Donna Ryan. "In fact, many medical treatments are frequently not reimbursed by insurance if they are for obesity. So this research is needed to show that primary care doctors are capable of helping obese patients lose weight to improve health, even those with extreme obesity. "

Ryan said losing only five-percent of body weight can reap healthy benefits for the extremely obese, and nearly 61-percent of those in her clinical trial achieved that. More than 40-percent lost 10-percent body weight or more.

Physicians Trained in Intensive Medical Intervention

Ryan and her team spread out across Louisiana to recruit and train practicing physicians and their office staffs in eight cities in what she called "intensive medical intervention," in which physicians used a combination of medication, low-calorie diets and behavior changes. All of the techniques were endorsed by national guidelines for obesity management. Training of physicians and their staffs took about a day and a half.

Funded by the Louisiana Office of Group Benefits, which provides health coverage for state employees, the research team contacted state employees, seeking participants to screen for and enroll in the trial. Nearly 400 participants enrolled in the two-year trial, called LOSS, using the nearest trained physicians.

About half of the participants received the intensive medical intervention, the other half received what Ryan called "usual care." 

Program Starts with Low-calorie Liquid Diet

Those in the intense intervention group were immediately placed on a low-calorie liquid diet. They gradually moved to a low calorie, highly controlled diet using meal replacements, and received weight loss medication and group behavioral therapy that included lessons in exercise, activity, self-monitoring and recommendations for walking, water exercise and weight training. The group sessions were supervised by office staff.

Recommended Activities

  • exercise
  • activity
  • self-monitoring
  • recommendations for walking
  • water exercise
  • weight training

Success in Daily Routine of Doctor's Practice

"We conducted this trial as close to the reality of a typical clinic setting as we could," Ryan said, "We didn't want to learn just if these strategies worked, but if they would work in the daily routine of a doctor's practice."

Challenge of Keeping Weight Off

Ryan noted that the continual challenge in weight loss is keeping weight off, and that means sticking with a routine.

More than 50% of the LOSS participants stuck with it for two years or more, keeping much of the weight off, but Ryan said that does leave room for improving weight loss maintenance.

The LOSS trial results were published in the current issue of the Archives of Internal Medicine.

The Pennington Biomedical Research Center is a campus of the Louisiana State University System and conducts basic, clinical and population research.
Researchers from the University of Alabama at Birmingham (UAB) have discovered that
restricting consumption of glucose, the most common dietary sugar, can extend the life of healthy human-lung cells and speed the death of precancerous human-lung cells, reducing cancer's spread and growth rate.

Calorie-Intake Restriction: Longevity and Prevent Diseases


The research has wide-ranging potential in age-related science, including ways in which calorie-intake restriction can benefit longevity and help prevent diseases like cancer that have been linked to aging, said principal investigator Trygve Tollefsbol, Ph.D., D.O., a professor in the Department of Biology.

  • Extend the Lifespan of Healthy Cells
  • Kill Off Cancer-Forming Cells

"These results further verify the potential health benefits of controlling calorie intake." Tollefsbol said. "Our research indicates that calorie reduction extends the lifespan of healthy human cells and aids the body's natural ability to kill off cancer-forming cells."

The UAB team conducted its tests by growing both healthy human-lung cells and precancerous human-lung cells in laboratory flasks. The flasks were provided either normal levels of glucose or significantly reduced amounts of the sugar compound, and the cells then were allowed to grow for a period of weeks.

"In that time, we were able to track the cells' ability to divide while also monitoring the number of surviving cells. The pattern that was revealed to us showed that restricted glucose levels led the healthy cells to grow longer than is typical and caused the precancerous cells to die off in large numbers," Tollefsbol said.

In particular, the researchers found that two key genes were affected in the cellular response to decreased glucose consumption. The first gene, telomerase, encodes an important enzyme that allows cells to divide indefinitely. The second gene, p16, encodes a well known anti-cancer protein.

Healthy Cell Growth

"Opposite effects were found for these genes in healthy cells versus precancerous cells. The healthy cells saw their telomerase rise and p16 decrease, which would explain the boost in healthy cell growth," Tollefsbol said. "The gene reactions flipped in the precancerous cells with telomerase decreasing and the anti-cancer protein p16 increasing, which would explain why these cancer-forming cells died off in large numbers."

The UAB research into the links between calorie intake, aging and the onset of diseases related to aging is thought to be a first of its kind given that it used the unique approach of testing human cells versus laboratory animals.

Caloric Restriction

"Our results not only support previous findings from the feeding of animals but also reveal that human longevity can be achieved at the cellular level through caloric restriction," Tollefsbol said.

"The hope is that this UAB breakthrough will lead to further discoveries in different cell types and facilitate the development of novel approaches to extend the lifespan of humans," he added.

Tollefsbol's research team included Yuanyuan Li, Ph.D., M.D., a UAB biology research associate, and Liang Liu, Ph.D., a UAB assistant professor of medicine.

The group's study titled "Glucose Restriction Can Extend Normal Cell Lifespan and Impair Precancerous Cell Growth Through Epigenetic Control of hTERT and p16 Expression" has been published in the online edition of The Journal of the Federation of American Societies for Experimental Biology, or FASEB Journal.

The research was funded by grants from the National Institutes of Health and the Glenn Foundation for Medical Research.

About UAB
Known for its innovative and interdisciplinary approach to education at both the graduate and undergraduate levels, UAB is an internationally renowned research university and academic medical center. Providing a broad-based graduate and undergraduate curriculum, the UAB Department of Biology is a dynamic academic partnership. Most members of the graduate faculty have research specialties in comparative biochemistry, physiology, environmental microbiology and eco-physiology of aquatic organisms.

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