A new study suggest that for some people, the ability to resist the temptation of extra calories is especially challenging as individuals may have “obesity genes” that increase the likelihood of a high-calorie diet – often consisting of high fat, sugary foods.

Nevertheless, the findings suggest that it may still be possible to minimize genetic risk by changing one’s eating patterns and being vigilant about food choices, in addition to adopting other healthy lifestyle habits, like regular physical activity.

The study, published online by the American Journal of Clinical Nutrition, reveals certain variations within the FTO and BDNF genes – which have been previously linked to obesity – may play a role in eating habits that can cause obesity.

“Understanding how our genes influence obesity is critical in trying to understand the current obesity epidemic, yet it’s important to remember that genetic traits alone do not mean obesity is inevitable,” said lead author Jeanne M. McCaffery, Ph.D., of The Miriam Hospital’s Weight Control and Diabetes Research Center.

“Our lifestyle choices are critical when it comes to determining how thin or heavy we are, regardless of your genetic traits,” she added. “However, uncovering genetic markers can possibly pinpoint future interventions to control obesity in those who are genetically predisposed.”

Researchers have known that individuals who carry a variant of the fast mass and obesity-associated gene FTO and BDNF (or brain-derived neurotrophic factor gene) are at increased risk for obesity.

Prior studies have determined that these genes are linked with overeating in children with the current study being one of the first investigations to extend the finding to adults.

Both FTO and BDNF genes influence the part of the brain that controls eating and appetite, although the mechanisms by which these gene variations influence obesity is still unknown.

In the current study, more than 2,000 participants completed a questionnaire about their eating habits over the past six months and also underwent geneotyping.

Researchers focused on nearly a dozen genes that have been previously associated with obesity. They then examined whether these genetic markers influenced the pattern or content of the participants’ diet.

Individuals who displayed variations in the FTO gene were found to be significantly associated with a greater number of meals and snacks per day, greater percentage of energy from fat and more servings of fats, oils and sweets.

The findings are largely consistent with previous research in children.

Moreover, researchers discovered individuals with BDNF variations consume more servings from the dairy and the meat, eggs, nuts and beans food groups. Individuals also consumed approximately 100 more calories per day, which McCaffery notes could have a substantial influence on one’s weight.

“We show that at least some of the genetic influence on obesity may occur through patterns of dietary intake,” she said. “The good news is that eating habits can be modified, so we may be able to reduce one’s genetic risk for obesity by changing these eating patterns.”

McCaffery says that while this research greatly expands their knowledge on how genetics may influence obesity, the data must be replicated before the findings can be translated into possible clinical measures.

Source: Miriam Hospital

Genetic man photo by shutterstock.

Often a man will stay on a diet while at home to avoid conflict, then splurge or even binge on unhealthy food when away from home.

“The key to married men adopting a healthier diet is for couples to discuss and negotiate the new, healthier menu changes as a team,” said Derek Griffith, Ph.D., assistant professor at the University of Michigan School of Public Health.

Although the finding seems obvious, most times it doesn’t happen, according to a new study called “She Looks Out For The Meals, Period.’ African-American Men’s Perceptions of How Their Wives Influence Their Eating Behavior and Dietary Health.”

In the study, researchers held focus group meeting with 83 African-American men. The majority of men said their wives didn’t consult them when helping them to adopt a healthier diet.

In many cases the husbands disliked the food changes even though the healthier diet was ordered by a physician. However, rather than discussing this issue with their wife and coming to a common ground on what they would eat, men stayed silent and focused on maintaining a happy home.

In fact, the only examples found of couples negotiating healthy food choices came about to benefit the children in the home, Griffith said.

Researchers discovered the absence of communication often compromised significant dietary change. After tasteless ground turkey for the fifth night in a row, some men would head to the all-you-can-eat buffet for “a landslide of food.”

“I think at dinner a lot of men are eating healthier, but they compensate for the dissatisfaction of not eating what they want by making unhealthier choices outside the home,” Griffith said.

Health care providers can improve dietary change compliance by recognizing that wives play a central role in what men eat at home, Griffith said.

Providers could instruct wife’s on communication and behavioral change strategies to encourage and support the new dietary behavior.

“Doctors could suggest that men have a tactful conversation with their wives in a way that ensures the husbands aren’t sleeping on the couch that night,” Griffith said.

The study was published this month in the journal Health Psychology.

Source: University of Michigan

Man eating a pizza photo by shutterstock.

A study recently published by a University of Colorado School of Medicine researcher shows that reward circuits in the brain are sensitized in anorexic women and desensitized in obese women. The findings also suggest that eating behavior is related to brain dopamine pathways involved in addictions.

Dr. Guido Frank, assistant professor director of the Developmental Brain Research Program at the CU School of Medicine, and his colleagues used functional magnetic resonance imaging (fMRI) to examine brain activity in 63 women who were either anorexic or obese. Scientists compared their results to women considered normal weight.

According to the researchers, the women were visually conditioned to associate certain shapes with either a sweet or a non-sweet solution and then received the taste solutions expectedly or unexpectedly. This task has been associated with brain dopamine function in the past, researchers explain.

The scientists found that an unexpected sweet-tasting solution resulted in increased neural activation of reward systems in the anorexic patients and diminished activation in obese women. In rodents, food restriction and weight loss have been associated with greater dopamine-related reward responses in the brain, the researchers noted.

“It is clear that in humans the brain’s reward system helps to regulate food intake,” said Frank. “The specific role of these networks in eating disorders, such as anorexia nervosa and, conversely, obesity, remains unclear.”

The study was published in Neuropsychopharmacology.

Source: University of Colorado Denver

“Our findings illustrate that what you eat affects how you think,” said Dr. Fernando Gomez-Pinilla, a professor of neurosurgery at the David Geffen School of Medicine at UCLA and a professor of integrative biology and physiology in the UCLA College of Letters and Science. “Eating a high-fructose diet over the long term alters your brain’s ability to learn and remember information. But adding omega-3 fatty acids to your meals can help minimize the damage.”

While earlier research revealed how fructose harms the body through its role in diabetes, obesity and fatty liver, this study uncovers how the sweetener influences the brain, according to the researchers.

The UCLA team concentrated on high-fructose corn syrup, an inexpensive liquid six times sweeter than cane sugar that is commonly added to processed foods from soft drinks to baby food. The average American consumes more than 40 pounds of high-fructose corn syrup each year, according to the U.S. Department of Agriculture.

“We’re not talking about naturally occurring fructose in fruits, which also contain important antioxidants,” said Gomez-Pinilla. “We’re concerned about high-fructose corn syrup that is added to manufactured food products as a sweetener and preservative.”

Gomez-Pinilla and study co-author Rahul Agrawal, Ph.D., a UCLA visiting postdoctoral fellow from India, studied two groups of rats that each consumed a fructose solution as drinking water for six weeks. The second group also received omega-3 fatty acids in the form of flaxseed oil and docosahexaenoic acid (DHA), which protects against damage to the synapses, the chemical connections between brain cells that enable memory and learning.

“DHA is essential for synaptic function — brain cells’ ability to transmit signals to one another,” he said. “This is the mechanism that makes learning and memory possible. Our bodies can’t produce enough DHA, so it must be supplemented through our diet.”

The animals were fed standard rat chow and trained on a maze twice daily for five days before starting the experimental diet. The research team tested how well the rats were able to navigate the maze, which contained numerous holes but only one exit. The scientists placed visual landmarks in the maze to help the rats learn and remember the way.

Six weeks later, the researchers tested the rats’ ability to recall the route and escape the maze.

“The second group of rats navigated the maze much faster than the rats that did not receive omega-3 fatty acids,” Gomez-Pinilla said. “The DHA-deprived animals were slower, and their brains showed a decline in synaptic activity. Their brain cells had trouble signaling each other, disrupting the rats’ ability to think clearly and recall the route they’d learned six weeks earlier.”

Those rats also developed signs of resistance to insulin, a hormone that controls blood sugar and regulates synaptic function in the brain. A closer look at the rats’ brain tissue suggested that insulin had lost much of its power to influence the brain cells.

“Because insulin can penetrate the blood-brain barrier, the hormone may signal neurons to trigger reactions that disrupt learning and cause memory loss,” Gomez-Pinilla said. “Insulin is important in the body for controlling blood sugar, but it may play a different role in the brain, where insulin appears to disturb memory and learning. Our study shows that a high-fructose diet harms the brain as well as the body. This is something new.”

Gomez-Pinilla advises people to keep fructose intake to a minimum and swap sugary treats for fresh berries and Greek yogurt. An occasional bar of dark chocolate that hasn’t been processed with a lot of extra sweetener is fine too, he said.

Still have a sweet tooth? Go ahead and indulge, but also eat foods rich in omega-3 fatty acids, like salmon, walnuts and flaxseeds, or take a daily DHA capsule, he said, recommending one gram of DHA per day.

“Our findings suggest that consuming DHA regularly protects the brain against fructose’s harmful effects,” said Gomez-Pinilla. “It’s like saving money in the bank. You want to build a reserve for your brain to tap when it requires extra fuel to fight off future diseases.”

Source: University of California-Los Angeles Health Sciences

Shannon Snapp, Ph.D., and her colleagues said many women in contemporary Western cultures are dissatisfied with their bodies, setting them up for eating problems. This led researchers to examine factors that make women more resilient when it comes to their body image in an effort to help those at risk of eating disorders.

They focused on first-year college women who are likely to experience self-consciousness as they compare themselves with peers and become involved in social groups and organizations that place a high value on appearance.

The researchers had 301 freshman complete questionnaires based on the Choate theoretical model, which hypothesizes that family support and low levels of pressure to attain the thin ideal are related to the rejection of the “Superwoman ideal,” positive views of physical competence, and effective stress-busting strategies.

These factors are associated with well-being, which in turn is linked to positive body image in women, said the researchers, who found that young women with a lot of family support and low levels of perceived sociocultural pressure from family, friends and the media regarding the importance of achieving a “thin and beautiful” ideal had a more positive body image.

These same women also rejected the Superwoman ideal, had a positive physical self-concept, and were armed with skills to deal with stress, the researchers report.

The scientists offer several practical recommendations for prevention programs aimed at young women at risk of eating disorders, such as helping them to evaluate and become comfortable with the multiple and often contradictory expectations placed upon them in today’s society; teaching them to use effective coping skills; fostering a positive view of their physical competence through exercise and health; and promoting holistic well-being and balance in their lives.

“It is particularly important for women to develop a sense of self-worth that is not solely based on appearance, and to build resilience to pressures they may receive from family, friends and the media,” the researchers concluded in the study, which was published online in Springer’s journal Sex Roles.

Source: Springer

Researchers discovered the phenomenon ultimately affects body mass and may be a factor in the continuing rise of obesity.

“‘Hedonic hunger’ refers to the desire to eat for pleasure, and to enjoy the taste, rather than to restore the body’s energy needs,” said Palmiero Monteleone, M.D., of the University of Naples SUN in Italy and lead author of this study.

“For example, desiring and eating a piece of cake even after a satiating meal is consumption driven by pleasure and not by energy deprivation. The physiological process underlying hedonic eating is not fully understood, but it is likely that endogenous substances regulating reward mechanisms like the hormone ghrelin and chemical compounds such as 2-arachidonoylglycerol (2-AG) are involved.”

In the current study, researchers assessed eight satiated healthy adults, feeding them each their personal favorite food and, later, a less-palatable food of equal caloric and nutrient value.

During the feeding period, researchers periodically measured 2-AG and ghrelin levels. The plasma levels of ghrelin and 2-AG increased during hedonic eating, with the favorite foods, but not with non-hedonic eating.

This increase suggests an activation of the chemical reward system, which overrides the body’s signal that enough has been eaten to restore energy.

“Hedonic hunger may powerfully stimulate overeating in an environment where highly palatable foods are omnipresent, and contribute to the surge in obesity,” said Monteleone.

“Understanding the physiological mechanisms underlying this eating behavior may shed some light on the obesity epidemic. Further research should confirm and extend our results to patients with obesity or with other eating disorders in order to better understand the phenomenon of hedonic eating.”

The study will be published in The Endocrine Society’s Journal of Clinical Endocrinology & Metabolism (JCEM).

Source: The Endocrine Society

Substance abuse is a common complement to binge eating, according to Penn State College of Medicine researchers. Investigators believe this finding may help to illuminate factors that promote substance abuse, addiction, and relapse.

“Drug addiction persists as a major problem in the United States,” said Patricia Sue Grigson, Ph.D. “Likewise, excessive food intake, like binge eating, has become problematic. Substance-abuse and binge eating are both characterized by a loss of control over consumption.

“Given the common characteristics of these two types of disorders, it is not surprising that the co-occurrence of eating disorders and substance abuse disorders is high. It is unknown, however, whether loss of control in one disorder predisposes an individual to loss of control in another.”

In the lab, Grigson and her colleagues found a link between bingeing on fat and the development of cocaine-seeking and -taking behaviors in rats.

This relationship suggests that conditions promoting excessive behavior toward one substance can increase the probability of excessive behavior toward another.

The findings are reported in the journal Behavioral Neuroscience.

To test if a history of binge eating on fat would augment addiction-like behavior toward cocaine, researchers provided the rats four different diets: normal rat chow; continuous access to an optional source of dietary fat; one hour of access to optional dietary fat daily; and one hour of access to dietary fat on Mondays, Wednesdays, and Fridays.

All four groups also had unrestricted access to nutritionally complete chow and water. The researchers then assessed the cocaine-seeking and -taking behaviors.

“Fat bingeing behaviors developed in the rats with access to dietary fat on Mondays, Wednesdays, and Fridays — the group with the most restricted access to the optional fat,” Grigson said.

This group tended to take more cocaine late in training, continued to try to get cocaine when signaled it was not available, and worked harder for cocaine as work requirements increased.

“While the underlying mechanisms are not known, one point is clear from behavioral data: A history of bingeing on fat changed the brain, physiology, or both in a manner that made these rats more likely to seek and take a drug when tested more than a month later,” Grigson said. “We must identify these predisposing neurophysiological changes.”

While the consumption of fat in and of itself did not increase the likelihood of subsequent addiction-like behavior for cocaine, the irregular binge-type manner in which the fat was eaten proved critical.

Rats that had continuous access to fat consumed more fat than any other group, but were three times less likely to exhibit addiction-like behavior for cocaine than the group with access only on Mondays, Wednesdays and Fridays.

“Indeed, while about 20 percent of those rats and humans exposed to cocaine will develop addiction-like behavior for the drug under normal circumstances, in our study, the probability of addiction to cocaine increased to approximately 50 (percent) for subjects with a history of having binged on fat,” Grigson said.

Researchers say additional studies will investigate in more detail how bingeing can lead to addiction-like behaviors.

Source: Penn State University

Scientist holding rat photo by shutterstock.

The event may be traumatic, such as relationship problems, abuse and sexual assault or could surface after changing school or moving.

As explained in an article found in the May issue of the Journal of Clinical Nursing, eating disorders includes conditions of anorexia and bulimia.

In the study, researchers from the University of Minnesota spoke to 26 women and one man receiving treatment from a specialist outpatient clinic. These individual who ranged in age from 17 to 64 had suffered from eating disorders for an average of 20 years.

“The aim of our study was to find out if there was any link between transitional events in family life and the onset of eating disorders,” said lead author Jerica M. Berge, Ph.D.

“Eating disorders are an important public health issue and knowing what causes them can help us to develop more effective treatment and support.”

The patients had a median age of 27 years and had been receiving treatment for between ten months and 18 years. Nine had anorexia nervosa, three had bulimia nervosa, one had both and the other 14 had eating disorders that did not meet the diagnostic criteria for any one specific condition.

Six key themes covered the significant (translational) events that preceded eating disorders:

• School transition. Some talked about the problems they had adapting to the more independent world of junior high school and others talked about leaving home to go to college and how they missed friends and family.

Starting college was very hard for one woman. “Nobody knew who I was…I was incredibly lonely with no support and I just stopped eating.” Another struggled to cope without regular support. “You don’t receive the daily love that you are used to growing up, you are left to provide that for yourself and I just wasn’t able to do it.”

• Relationship changes. Breaking up with a partner affected some participants and others talked about their parents splitting up and moving on.

When her father got a new girlfriend when she was seven, one woman lost the close relationship they had enjoyed. “Overnight she became the most important thing in his life…his girlfriend would be really mean to me and my dad wouldn’t defend me.” Another woman described how her dad left for “the perfect Barbie”, adding “I was so mad at my dad for choosing her over us…I think that is when my eating disorder really began.”

• Death of a family member. The death of a family member or close friend often proved traumatic, with people saying that they didn’t not know how to deal with their grief and that they received little support.

One woman’s sister died when she was five, but no-one talked about this “major event” in her life. “I started to eat – to compensate for feelings of anxiety.” Another lost her mother to an eating disorder when she was 11. She found herself living in a single-parent household where she was given “so much freedom with not much emotional support… I lost control.”

• Home and job transition. Some were affected by their family relocating or losing their job and described how they felt lonely, unsupported and lacked close relationships during these transitions.

A new job left one woman with little time for friends and she struggled to relate to her workmates who were all much older than her. “I felt really alone and had no-one to talk to or hang out with.” Moving house at 16 was really hard for another woman. “I just felt lost and my eating problems began.”

• Illness/hospitalization. A number had been ill and some said that their weight loss made them feel good and prompted positive comments from others.

Having viral meningitis scared one woman – she realized she had no control over her illness, but could control her eating. “I guess I was thinking that if I could be this small, people would kind of take care of things for me.” Being diagnosed with hypoglycemia aged from 17 to 64 and being told she needed to eat frequently was the start of another woman’s problems. “I started to think constantly about food…since then I’ve had a real struggle with bingeing.”

• Abuse/sexual assault/incest. Some talked about abusive events and how they felt let down or deserted by the very friends and family they needed to support them. Two said they ate more to become unattractive or bigger and intimidating.

Being sexually abused by her brother triggered one woman’s eating disorder. “I think in a way I developed the eating disorder just to get away from it…Just to kill the pain because I couldn’t tell anyone.” Another woman started eating to try and stop the abuse and violence from her partner. “I thought if I gained weight that he would leave me alone or I could fight him back.”

Berge said the study confirms that eating disorders can be triggered by a number of life changes and that lack of support was a common theme.

“We hope that our findings will be of interest to parents as well as health professionals as they underline the need for greater awareness and support at times of change and stress.”

Source: Wiley-Blackwell

Young woman weighing herself photo by shutterstock.

Although the sleep-deprived burn about the same amount of calories, they consume about 300 more per day.  Since it only takes about 3,500 calories to add one pound to your body, a few hundred calories a day can quickly turn into extra weight.

According to sleep disorder specialist Michael Breus, Ph.D., when a person gets too little sleep, his metabolism slows down to save energy. That slowdown triggers the release of the hormone cortisol, which in turn increases appetite. The body senses that it needs more energy, so it asks for more food.

Lack of sleep also causes the body to release more ghrelin, a hormone that signals hunger, and less leptin, the hormone that tells your stomach that it’s full. This causes the body to crave more food but lacks the sensitivity to know when to quit eating. And, of course, being awake more hours gives you more time to eat.

“The later you’re up at night, the greater the likelihood that you’re going to eat,” Breus says. And “you’re more likely to eat high-fat, high-carb foods.”

Furthermore, the body burns the most calories during REM sleep, a deeply restful phase, and a lack of sleep means less time in REM.

For best results, experts suggest getting 7.5 hours of sleep a night. If you have trouble sleeping, they advise that you stick to a nightly routine, exercise during the day, write your worries in a journal, and keep pre-bedtime activities relaxing.

The research is published in the American Journal of Clinical Nutrition.

Source:  New York Obesity Nutrition Research Center

A new discovery by genetics researchers identifies at least two new gene variants that increase the risk of common childhood obesity.

“This is the largest-ever genome-wide study of common childhood obesity, in contrast to previous studies that have focused on more extreme forms of obesity primarily connected with rare disease syndromes,” said lead investigator Struan F.A. Grant, Ph.D.

“As a consequence, we have definitively identified and characterized a genetic predisposition to common childhood obesity.”

The study appears online in Nature Genetics.

Experts warn that childhood obesity threatens to shorten the life-span of our children for the first time in history. The dramatic rise in obesity among youth is influenced by environmental factors, such as food choices and sedentary habits.

However, twin studies and other family-based evidence have suggested a genetic component to the disease as well. While some studies have identified gene variants contributing to obesity in adults and in children with extreme obesity, relatively little is known about the influence of genes on regular childhood obesity.

“The Center for Applied Genomics at the Children’s Hospital of Philadelphia has recruited and genotyped the world’s largest collection of DNA from children with common obesity,” said Grant.

“However, in order to have sufficient statistical power to detect novel genetic signals, we needed to form a large international consortium to combine results from similar datasets from around the world.”

The National Institutes of Health partly funded this research, which analyzed previous studies supported by many other European, Australian and North American organizations.

The current meta-analysis included 14 previous studies encompassing 5,530 cases of childhood obesity and 8,300 control subjects, all of European ancestry. The study team identified two novel loci, one near the OLFM4 gene on chromosome 13, the other within the HOXB5 gene on chromosome 17.

They also found a degree of evidence for two other gene variants. None of the genes were previously implicated in obesity. “The known biology of three of the genes,” added Grant, “hints at a role of the intestine, although their precise functional role in obesity is currently unknown.”

“This work opens up new avenues to explore the genetics of common childhood obesity,” said Grant. “Much work remains to be done, but these findings may ultimately be useful in helping to design future preventive interventions and treatments for children, based on their individual genomes.”

Source: Children’s Hospital of Philadelphia

Boy eating photo by shutterstock.

“This misperception is important because the first step in dealing with a weight problem is knowing that you have one,” said Margarita Teran-Garcia, M.D., a professor of food science and human nutrition at the University of Illinois.

The study is part of the Up Amigos project, a collaboration between researchers at the University of Illinois and the Universidad Autónoma de San Luis Potos in Mexico. In physical exams, the height, weight, and body mass index (BMI) of 3,622 18- to 20-year-old applicants to the Mexican university were recorded. The applicants also completed surveys in which they reported their weight.

Among the men, 33.6 percent were overweight or obese, but only 16.9 percent described themselves as being in those categories. For women, the gap between perception and reality was smaller — 27.8 percent of women were actually overweight or obese, but only 21.2 percent believed that they were.

Identifying weight problems at the beginning of adult life has important health consequences, Teran-Garcia said. “If these young people follow the wrong trajectory, continuing to accumulate weight, they are likely to develop heart disease and diabetes. It’s much better if they deal straightforwardly with the fact that they’re gaining weight while they’re young.”

Teran-Garcia noted Mexico has the highest rates of obesity and diabetes in the world, and Latinos, the fastest-growing immigrant population in the United States, bring their weight problems, cultural behaviors, and perceptions with them.

“It’s important to understand these cultural differences and be able to see things from the Latino perspective so we can create successful interventions,” she said.

Very few participants in the Mexican study overestimated their weight, but those who did were most often female, younger, had parents with less education, and watched more television. If a young woman believes she weighs more than she does, she is at risk for developing anorexia or bulimia, the researchers said.

Ideal body image changes with exposure to Western media, the researchers noted. “The curvier female figure once appreciated in Latino culture is being replaced by the ultra-thin ideal promoted by Western advertisers,” Teran-Garcia said.

The researchers plan to continue their work in identifying genetic predispositions for obesity in the participants, then studying the interaction between those genetic markers and family environment, cultural beliefs, mental and physical health, and whether and how much the students exercise.

“We will be able to follow many of these students for some time. We expect to have an exit interview with at least a third of our study participants when they leave college,” added researcher Flavia Cristina Drumond Andrade, Ph.D.

Source: University of Illinois

Current medical regimens include the use of off-label medications (medications that are normally used for other psychiatric conditions). These medications have rarely been tested for their effectiveness in animal models.

In a new study, University of Chicago researchers used low doses of a commonly used atypical antipsychotic drug for a mouse model of anorexia nervosa. They discovered an improved survival rate suggesting the medication may offers promise for the relatively common disorder.

In the experiment, mice treated with small doses of the drug olanzapine (brand name Zyprexa) were more likely to maintain their weight when given an exercise wheel and restricted food access, conditions that produce activity-based anorexia (ABA) in animals. The antidepressant fluoxetine (Prozac), commonly prescribed off-label for anorexic patients, did not improve survival in the experiment.

“We found over and over again that olanzapine was effective in harsher conditions, less harsh conditions, adolescents, adults — it consistently worked,” said the paper’s first author, doctoral student Stephanie Klenotich.

The study, published in Neuropsychopharmacology, was the product of a rare collaboration between laboratory scientists and clinicians seeking new treatment options for anorexia nervosa.

As many as one percent of American women will suffer from anorexia nervosa during their lifetime, but only one-third of those people will receive treatment.

Patients with anorexia are often prescribed off-label use of drugs designed for other psychiatric conditions, but few studies have tested the drugs’ effectiveness in animal models.

“Anorexia nervosa is the most deadly psychiatric disorder, and yet no approved pharmacological treatments exist,” said senior author Stephanie Dulawa, Ph.D. “One wonders why there isn’t more basic science work being done to better understand the mechanisms and to identify novel pharmacological treatments.”

Experts say the solution is more difficult than expected. One challenge is finding a medication that patients with anorexia nervosa will agree to take regularly, said co-author Daniel Le Grange, Ph.D. Drugs that directly cause weight gain or carry strong sedative side effects are often rejected by patients.

“Patients are almost uniformly very skeptical and very reluctant to take any medication that could lower their resolve to refrain from eating,” Le Grange said. “There are long-standing resistances, and I think researchers and clinicians have been very reluctant to embark on that course, since it’s just littered with obstacles.”

Both fluoxetine and olanzapine have been tried clinically to supplement interventions such as family-based treatment and cognitive-behavioral therapy. But their direct effect on anorexia nervosa behavior — in humans or animals — has not been detected.

Given the success of the study, researchers hope to investigate the effect of olanzapine on a more detailed basis hoping to discover the mechanisms of action, and targeted receptor systems.

Klenotich said, “Hopefully, we can develop a newer drug that we can aim towards the eating disorders clinic as an anorexic-specific drug that might be a little more acceptable to patients.”

The study offers support for the clinical use of olanzapine, for which clinical trials are already under way to test in patients.

Le Grange said the development of a pharmacological variant that more selectively treats anorexia nervosa could be a helpful way to avoid the “stigma” of taking an antipsychotic while giving clinicians an additional tool for helping patients.

“I think the clinical field is certainly very ready for something that is going to make a difference,” Le Grange said.

“I’m not saying there’s a ‘magic pill’ for anorexia nervosa, but we have been lacking any pharmacological agent that clearly contributes to the recovery of our patients. Many parents and many clinicians are looking for that, because it would make our job so much easier if there was something that could turn symptoms around and speed up recovery.”

Source: University of Chicago Medical Center

Man holding a pill bottle photo by shutterstock.

In the studies, neuroscientists discovered a variety of brain activity across a spectrum of eating behaviors — from extreme overeating to food deprivation. This variation in neurological response influences both the development of an eating disorder and the way in which we respond to a weight loss program.

Eating disorders have the highest mortality rate of any mental illness. Currently, more than two-thirds of the U.S. population are overweight or obese — a health factor associated with cardiovascular issues, diabetes, and cancer.

“This body of work not only increases our understanding of the relationship between food and brain function but can also inform weight loss programs,” said Laura Martin, Ph.D., one of several researchers whose work being presented at a meeting of cognitive neuroscientists in Chicago.

“One of the most intriguing aspects of these studies of the brain on food,” Martin said, is that they show “consistent activations of reward areas of the brain that are also implicated in studies of addiction.”

However, how those reward areas respond to food differs between people depending on their eating behaviors, according to the new brain imaging study by Laura Holsen of Harvard Medical School and Brigham and Women’s Hospital and colleagues.

Holsen’s team conducted fMRI brain scans of individuals with one of three eating conditions — anorexia nervosa, simple obesity, and Prader-Willi syndrome (extreme obesity) — as well as healthy control subjects.

When hungry, those with anorexia, who severely restrict their food intake, showed substantially decreased responses to various pictures of food in regions of their brains associated with reward and pleasure. For those who chronically overeat, there were significantly increased responses in those same brain regions.

“Our findings provide evidence of an overall continuum relating food intake behavior and weight outcomes to food reward circuitry activity,” Holsen says.

Holsen believes her findings are relevant for everyday eating decisions in healthy individuals. “Even in individuals who do not have eating disorders, there are areas of the brain that assist in evaluating the reward value of different foods, which in turn plays a role in the decisions we make about which foods to eat.”

In a related research effort, Kyle Simmons of the Laureate Institute works with fMRI scans to determine the brain’s response when an individual sees food.

The brain scans show an apparent overlap in the brain region called the insula that responds to seeing food pictures, and the region of the insula that processes taste, the “primary gustatory cortex.”

Simmons is currently expanding this work to better understand the differences in taste preferences between lean, healthy individuals and obese ones. “We simply don’t know yet if differences exist between lean and obese participants,” he says.

“And knowing which brain regions underlie inferences about food taste and reward is critical if we are going to develop efficacious interventions for obesity and certain eating disorders, both of which are associated with enormous personal and public health costs.”

Source: Cognitive Neuroscience Society (CNS)

Brain network photo by shutterstock.

The study, published in the March issue of the Journal of Food Science, published by the Institute of Food Technologists, looked at two specific genes: TAS2R38, a bitter taste receptor, and CD36, a possible fat receptor. Food scientists said they hope that by understanding the role of these two genes, they may be able to help people who have trouble controlling how much fat they eat.

Most food scientists acknowledge the texture of fat plays a big role in how it is perceived in the mouth. For example, ice cream is typically “rich, smooth and creamy.”

Scientists also have determined that certain fats can be detected by smell. Only recently have they begun to explore that most fats have a taste too.

In the recent study, researchers focused on one ethnic group to limit genetic variations that could reduce the ability to detect associations with the gene of interest. They determined the fat preferences and CD36 status of more than 300 African-American adults.

Investigators from the New York Obesity Research Center identified a genetic variant present in 21 percent of the African-Americans that was associated with higher preferences for added fats and oils, such as salad dressings and cooking oils. They also found study participants with this genetic variance ranked Italian salad dressings creamier than those who have other genotypes.

The other gene explored by these researchers, TAS2R38, is the receptor for bitter taste compounds. About 70 percent of U.S. adults and children are “tasters” of these compounds, while the remaining 30 percent are “nontasters,” food scientists report.

Recent study results indicate that nontasters tend to be poor at discriminating fat in foods, partly because they have fewer taste buds than “tasters.” This may lead nontasters to eat more higher-fat foods to compensate.

The researchers plan to continue examining the role of these genotypes in weight management, adding that genetic testing by the food industry may not be too far off.

Once studies like these are more fully developed, there may be a role for genotyping study participants when it comes to testing a new product, researchers say. For example, a company wanting to test out a new salad dressing may include people with different genes relating to fat perception to get a more accurate opinion. In addition, the food industry will be able to create different kinds of foods for different populations, food scientists said.

Source: Institute of Food Science & Technology

Sarah A. Mustillo, a Purdue University researcher, discovered the surprising findings among obese white teenage girls.

“We found that obese black and white teenage girls who transitioned out of obesity continued to see themselves as fat, despite changes in their relative body mass,” said Mustillo. “Further, obese white girls had lower self-esteem than their normal-weight peers and their self-esteem remained flat even as they transitioned out of obesity.”

Reducing obesity among children and teens is a major policy objective for health professionals. Currently, the Centers for Disease Control and Prevention report that about 17 percent of American children ages 2-19 are obese.

“If the current national movement to end childhood obesity is successful, we can anticipate many young people moving from obese into the normal weight range, which will result in better physical health,” Mustillo said.

“I wanted to know if the same thing would happen for psychological health. Girls often struggle with self-esteem anyway during adolescence and, therefore, it is troubling to find that the negative effects of larger body size can outlive the obesity itself.”

The study, based on data from the National Heart, Lung and Blood Institute Growth and Health Study, is in the Journal of Health and Social Behavior.

Researchers looked at the health and weight of more than 2,000 black and white girls for a 10-year period beginning at ages 9 to 10. Investigators separated the girls into one of three groups — normal weight, transitioned out of obesity and chronically obese — based on their body mass trends during the 10-year period.

Investigators discovered a difference in self-esteem levels between races. Self-esteem for black girls transitioning from the obese to the normal range did rebound; however, both races continued to have negative body perceptions.

“The self-esteem for black girls was lower overall to begin with, but for those who moved into the normal weight range, self-esteem increased more than it did for any other group of girls,” Mustillo said. “We would like to look at this at more closely to understand how subcultural norms influence this process.

“We did not show that self-esteem stayed flat because girls continued to see themselves as heavy, but just that they happened at the same time,” she said.

“Even so, providing mental health assistance during the weight loss process could be a benefit. Understanding and addressing body image, identity and self-esteem issues could ultimately help keep the weight off. Why keep dieting and exercising if you are still going to see yourself as fat?”

Experts agree that more research is needed to understand why girls feel this way, but Mustillo, who focuses on obesity trends in adolescence, said the feeling of lesser self-worth might be difficult to shake because society is full of negative stereotypes and messages about obesity.

“Studies show that children internalize stereotypes and negative perceptions of obese people before they ever become obese themselves, so when they do enter that stigmatized state, it affects their sense of self-worth,” she said.

“Then, whether they are gaining or losing weight, the negative message they have internalized and feelings of worthless may stick with them.”

Another aspect of this study to consider is that the data set used is from the 1980s and 1990s, and doesn’t reflect today’s higher obesity rates.

“Obesity is more common today than it was 10 to 20 years ago, so perhaps it is becoming less stigmatized,” she said. “Or, will the increase of anti-obesity campaigns counteract any greater acceptance?”

In her future research, Mustillo will ascertain if there are certain periods during adolescence when individuals are more vulnerable to mental health stigmas associated with obesity.

Source: Purdue University