April 11, 2006, 11:06 PM CT

Teen Dieters Are More Likely To Be Overweight

Adolescents who diet and use unhealthy weight-control behaviors are more likely to be overweight and put themselves at risk for eating disorders in the future, as per new research done at the University of Minnesota.

A study reported in the recent issue of the Journal of the American Dietetic Association found that adolescents with unhealthy weight-control behaviors were three times more likely to be overweight five years later. In addition, adolescents using unhealthy weight-control behaviors were at an increased risk for out-of-control binge eating, self-induced vomiting, and the use of diet pills, laxatives, and diuretics.

"This study shows that a shift from dieting and drastic weight-control behaviors to long-term healthy eating and physical activity is necessary among adolescents," said Dianne Neumark-Sztainer, Ph.D., study author and professor of epidemiology and community health at the University of Minnesota. "A change in lifestyle is needed to prevent obesity and eating disorders in this population."

Scientists conducted a longitudinal study of over 2,000 adolescents to determine risk for gains in BMI, overweight status, binge eating, extreme weight-control behaviors, and eating disorders after five years. Subjects completed two Project E.A.T. surveys in 1999 and 2004 to determine if those who reported dieting and different weight-control behaviors are at an increased risk for obesity and eating disorders.........

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April 10, 2006, 7:37 PM CT

New Approach For Curbing Obesity

Hot fudge sundaes and french fries aside, new research suggests obesity is due at least in part to an attraction between leptin, the hormone that signals the brain when to stop eating, and a protein more recently associated with heart disease. Reporting in Nature Medicine, University of Pittsburgh scientists provide evidence that C-reactive protein (CRP) not only binds to leptin but its hold impairs leptin's role in controlling appetite. The results may help explain why obese people have so much trouble losing weight as well as point to a different target for the pharmaceutical therapy of obesity.

"There's been a lot of interest in leptin as a means to curb appetite and reduce weight but clinical trials have had disappointing results. Our studies suggest an approach that should be further studied is one that disrupts the interaction between leptin and CRP, thereby restoring leptin's ability for signaling. We need to better understand how this interaction works and investigate the underlying mechanisms involved," said Allan Z. Zhao, Ph.D., assistant professor of cell biology and physiology, University of Pittsburgh School of Medicine, and the study's senior author.

Leptin is secreted by fat - the more fat, the more leptin - yet it is named for the Greek word leptos, which means "thin." In a region of the brain called the hypothalamus, leptin binds to receptors residing on the surface of neurons, setting off signals that tell the brain to stop eating and the body to expend energy by burning calories. While obese people produce much higher levels of leptin than thin and normal-weight individuals, they are somehow resistant to its effects. Dr. Zhao and his co-authors believe the binding of CRP to leptin may be the reason this is so. Their argument seems all the more plausible since CRP also is elevated in obese people. CRP, which is produced by the liver and typically rises as part of the immune system's inflammatory response, is gaining favor as a marker for high blood pressure and heart disease risk, known complications of obesity.........

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April 10, 2006, 7:13 PM CT

Obesity: Is It Genetic?

Do you have big hips or a "beer" belly? Are you "apple-shaped" or "pear-shaped"? It makes a difference, since we know that abdominal obesity is linked to diabetes and a number of other metabolic conditions, i.e., the metabolic syndrome. What's new is that, as per a new study led by scientists at Joslin Diabetes Center in Boston, both obesity and body shape seem to be controlled by important genes that are part of the mechanisms regulating normal development.

"By looking at your genes, we can tell how fat you are and how your body fat will be distributed," said lead researcher C. Ronald Kahn, M.D., President of Joslin and the Mary K. Iacocca Professor of Medicine at Harvard Medical School. In lower animals, he added, it's long been known that genes play an important role in the body's development. "Genes tell the body where the head goes and where the tail goes, what goes on the front and what goes on the back. In insects, genes determine if the wings go on the front or back and whether they will be large or small. So it's not surprising that in humans, genes may determine how a number of fat cells we have and where they are located," he said.

Together with Joslin post-doctoral fellow Stephane Gesta, Ph.D., and his colleagues at the University of Leipzig in Gera number of, the scientists for the first time used gene chips as a tool to understand what genes might control the development of fat inside the abdomen versus fat under the skin. The resulting study will be published online today, April 10, in the journal Proceedings of the National Academy of Sciences.........

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April 9, 2006, 7:48 PM CT

Targeting Fat With Laser

Fat may have finally met its match: laser light. Scientists at the Wellman Center for Photomedicine at Massachusetts General Hospital, Harvard Medical School and the Department of Energy's Thomas Jefferson National Accelerator Facility (Jefferson Lab) have shown, for the first time, that a laser can preferentially heat lipid-rich tissues, or fat, in the body without harming the overlying skin. Laser therapies based on the new research could treat a variety of health conditions, including severe acne, atherosclerotic plaque, and unwanted cellulite. The result will be presented at the American Society for Laser Medicine and Surgery (ASLMS) 26th Annual Meeting in Boston, Mass.

In the first part of the study, the scientists used human fat obtained from surgically discarded normal tissue. Based on a fat absorption spectrum, tissue was exposed to a range of wavelengths of infrared laser light (800-2600 nanometers) using the Free-Electron Laser facility at Jefferson Lab. The scientists measured how selected wavelengths heated the fat and compared the result to a similar experiment conducted with pure water. At most infrared wavelengths, water is more efficiently heated by infrared light; however, the scientists found three wavelengths â€" 915, 1210 and 1720 nm â€" where fat was more efficiently heated than water.........

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April 5, 2006, 11:48 PM CT

Effects Of Weight Loss In Adolescents

A team of scientists at Washington University School of Medicine in St. Louis is studying how fatty liver disease affects sugar and fat metabolism in overweight adolescents and how losing weight affects the condition. In the last 30 years, the number of overweight children has doubled in the United States, and overweight children are at increased risk for the problem.

In fatty liver disease, fat accumulates in liver cells. A patient is diagnosed with fatty liver when there is more than 5 percent fat in the liver. In children and adolescents, fatty liver is most common in those who are overweight, but it also can occur in young people with diabetes or, less commonly, with other conditions.

Those with fatty liver disease may have an enlarged liver or elevations in liver enzyme tests. Most do not have obvious symptoms, but some may complain of fatigue, malaise or vague abdominal pain that can bring them to the attention of a physician. If fatty liver goes untreated and risk factors are not controlled, a small percentage of young people may progress to liver scarring or even liver failure.

Fatty liver disease is thought to affect about 20 percent of the population in the developed world, but like type 2 diabetes, it has been uncommon in young people until recently.........

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April 5, 2006, 11:40 PM CT

Calorie Restriction Reduces Markers Of Aging

Can eating a low-calorie yet nutritionally balanced diet extend human life as it does in rodents? Preliminary research suggests it might, so scientists at Washington University School of Medicine in St. Louis are launching a long-term study to find out.

More than a decade ago several researchers, including John O. Holloszy, M.D., professor of medicine at Washington University, demonstrated that stringent and consistent caloric restriction increased the maximum lifespan in mice and rats by about 30 percent and protected them against atherosclerosis and cancer.

Human study has been difficult because calorie restriction requires a very strict diet regimen, both to keep the total number of calories low and to insure that people consume the proper balance of nutrients. However, there is a group called the Calorie Restriction Society that is devoted to limiting caloric intake in hopes of improving health and extending lives. Society members, who call themselves CRONies (Calorie Restriction with Optimal Nutrition), have developed ways to eat low calorie/high nutrition diets.

Luigi Fontana, M.D., Ph.D., assistant professor of medicine at Washington University and an investigator at the Istituto Superiore di Sanita in Rome has done extensive research with CRONies, most recently reporting in the Jan. 17 issue of the Journal of the American College of Cardiology that the hearts of people on calorie restriction appeared more elastic than those of age- and gender-matched control subjects. Their hearts were able to relax between beats in a way similar to the hearts of younger people.........

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April 5, 2006, 11:36 PM CT

Cohabiting Is Bad For Women's Health

WOMEN eat more unhealthy foods and tend to put on weight when they move in with a male partner, as per a new report by the University of Newcastle upon Tyne.

Conversely, a man's diet tends to become healthier when he starts cohabiting with a female partner - and her influence has a long-term positive impact.

The reason for the change in dietary habits, say experts, is that both partners try to please each other during the 'honeymoon period' at the start of a cohabiting relationship, by adjusting their routine to suit their partner and eating food that he or she likes.

However, women have the strongest long-term influence over the couple's diet and lifestyle, mainly because the majority of female partners still assume the traditional role of food shopper and cook.

The report, by Newcastle University's Human Nutrition Research Centre, is reported in the health professional title Complete Nutrition.

It reviews the findings of a variety of research projects from the UK, North America and Australia which looked at the eating and lifestyle habits of cohabiting heterosexual couples, including married couples.

The research shows that women are more likely to put on weight and increase their consumption of foods high in fat and sugar when they move in with their partner. Men, conversely, report a reduction in 'bad foods' when they begin to cohabit, reducing fat and sugar and increasing consumption of vegetables.........

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April 4, 2006, 8:50 PM CT

Preventing Injury To Muscles

If you're a mouse, then stretching before you exercise is a good thing - even as long as two weeks before your next cheese hunt or cat run. But if you're reading this for yourself, it's a bit more complicated.

When most of us think of stretching, we're imagining at a minimum jogging, and probably something more like downhill skiing or sprints. But when University of Michigan scientists Nicole Lockhart and Susan Brooks talk stretching, their real interest is how to condition older folks' muscles so they'll eventually be willing to do even a little exercise to garner all the benefits that will follow.

"The elderly are far more susceptible to contraction-induced injury," notes Lockhart, lead author in two related papers being presented in American Physiological Society sessions at Experimental Biology in San Francisco. "Sometimes just by normal activity or a sudden movement a leg will jut out too far and they'll suffer a minor injury, but they'll be wary of further damage," she said.

Protect those muscles, as minor injuries may be cumulative

Brooks, her adviser, added: "We believe that cumulative muscle injury may contribute to the loss of muscle mass as we grow old. So protecting muscles at all times is a good thing. And understanding how stretching increases resistance to injury will really help to do this".........

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April 2, 2006, 8:35 PM CT

Juice improves health, No increase Obesity Risk

As per a recent analysis of government data, children who drank 100 percent juice had healthier overall diets than non-juice consumers and consumed more total fruits, fiber and key nutrients such as vitamin C, potassium, magnesium and folate. The juice consumers also had significantly lower intakes of total fat, saturated fat and sodium.

As per the researchers, the group of 100 percent juice consumers also had equal or lower bodyweights and body mass indexes (BMI) than the non-juice consumers, adding to the scientific evidence which shows that 100 percent juices play a role in a healthful diet and are not associated with overweight. The research is being presented this week at the Experimental Biology 2006 meeting.

Using well-established data from the government's National Health and Nutrition Examination Survey (NHANES), researcher Victor Fulgoni, Ph.D., examined the impact of 100 percent juice in children's diets on bodyweight and BMI among more than 7,500 children ages 2-18. This analysis of the most recent NHANES database (1999-2002), combined with growth chart data from the Centers for Disease Control and Promotion (CDC), found that juice consumers had significantly lower z-scores for body mass index for their age than non-juice consumers (body mass index is a relative measure taking into consideration body weight and body size and z-scores represent the distance from the mean or average of the total population studied). While there were no differences specifically in BMI between the juice consumers and non-juice consumers for children aged 2-11, there were differences in children aged 12-18 years -- the juice consumers had significantly lower BMIs than those who drank no juice at all.........

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April 1, 2006, 8:27 AM CT

Vegetarian Diet Help To Lose Weight

Adhering to a strict vegetarian diet is an effective way of reducing your diet, according to findings from a scientific review published in April's Nutrition Reviews. This review shows that a vegetarian diet is highly effective for weight loss. Vegetarian populations tend to be slimmer than meat-eaters, and they experience lower rates of heart disease, diabetes, high blood pressure, and other life-threatening conditions linked to overweight and obesity. The new review, which is a meta-analysis, compiling data from 87 prior studies, shows the weight-loss effect does not depend on exercise or calorie-counting, and it occurs at a rate of approximately 1 pound per week.

Rates of obesity in the general population are skyrocketing, while in vegetarians, obesity prevalence ranges from 0 percent to 6 percent, note study authors Susan E. Berkow, Ph.D., C.N.S., and Neal D. Barnard, M.D., of the Physicians Committee for Responsible Medicine (PCRM).

The authors found that the body weight of both male and female vegetarians is, on average, 3 percent to 20 percent lower than that of meat-eaters. Vegetarian and vegan diets have also been put to the test in clinical studies, as the review notes. The best of these clinical studies isolated the effects of diet by keeping exercise constant. The scientists found that a low-fat vegan diet leads to weight loss of about 1 pound per week, even without additional exercise or limits on portion sizes, calories, or carbohydrates.........

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