Posts tagged binge eating

Posts tagged binge eating
Understanding Binge Eating and Obesity
Researchers at the University of Cambridge have developed a novel method for evaluating the treatment of obesity-related food behavior. In an effort to further scientific understanding of the underlying problem, they have published the first peer-reviewed video of their technique in JoVE, the Journal of Visualized Experiments.
In the video, the authors demonstrate their means of objectively studying the drivers and mechanisms of overconsumption in humans. To do this, they assesses their subject’s willingness to work or pay for food, and they simultaneously track the corresponding brain activity using an MRI scanner.
“We present alternative ways of exploring attitudes to food by using indirect, objective measures—such as measuring the amount of energy exerted to obtain or view different foods, as well as determining brain responses during the anticipation and consumption of desirable foods,” said the lab’s principal investigator, Dr. Paul Fletcher. He and his colleagues use participant hand-grip intensity (referred to as “grip force” in the video) to calculate the motivation for a given food reward.
According to Dr. Fletcher, typical approaches for evaluating anti-obesity type drugs rely on more subjective methods—like having test subjects self-report their ratings of hunger and cravings.
“When a person is asked how much they subjectively desire a food, they may feel pressured to give a ‘correct’ rather than a true answer,” said Dr. Fletcher, “[Our] grip force task may, under certain circumstances, present a more accurate reflection of what they really want.”
Dr. Fletcher and his colleagues brought the technique to JoVE after using it in their earlier publication, “Food images engage subliminal motivation to seek food,” published in 2011. They decided to publish a video capturing the protocol “Because it offered the opportunity to demonstrate the methods more fully,” he said.
In the video, Dr. Fletcher expands on the purpose of publishing the method with JoVE. “Individuals new to the technique may struggle because there aren’t many examples of grip-force tasks published in the literature, and there are no full and clear descriptions of how to design and set up the tasks,” he said.
With rising concerns surrounding obesity, researchers can use the technique presented in the JoVE video to determine the efficacy of a potential emerging market in anti-obesity medicine.
Deep brain stimulation (DBS) in a precise region of the brain appears to reduce caloric intake and prompt weight loss in obese animal models, according to a new study led by researchers at the University of Pennsylvania. The study, reported in the Journal of Neuroscience, reinforces the involvement of dopamine deficits in increasing obesity-related behaviors such as binge eating, and demonstrates that DBS can reverse this response via activation of the dopamine type-2 receptor.
"Based on this research, DBS may provide therapeutic relief to binge eating, a behavior commonly seen in obese humans, and frequently unresponsive to other approaches," said senior author Tracy L. Bale, PhD, associate professor of neuroscience in Penn’s School of Veterinary Medicine’s Department of Animal Biology and in the Perelman School of Medicine’s Department of Psychiatry. DBS is currently used to reduce tremors in Parkinson’s disease and is under investigation as a therapy for major depression and obsessive-compulsive disorder.
Nearly 50 percent of obese people binge eat, uncontrollably consuming palatable highly caloric food within a short period of time. In this study, researchers targeted the nucleus accumbens, a small structure in the brain reward center known to be involved in addictive behaviors. Mice receiving the stimulation ate significantly less of the high fat food compared to mice not receiving DBS. Following stimulation, mice did not compensate for the loss of calories by eating more. However, on days when the device was turned off, binge eating resumed.
Researchers also tested the long-term effects of DBS on obese mice that had been given unlimited access to high-fat food. During four days of continuous stimulation, the obese mice consumed fewer calories and, importantly, their body weight dropped. These mice also showed improvement in their glucose sensitivity, suggestive of a reversal of type 2 diabetes.
“These results are our best evidence yet that targeting the nucleus accumbens with DBS may be able to modify specific feeding behaviors linked to body weight changes and obesity,” Bale added.
“Once replicated in human clinical trials, DBS could rapidly become a treatment for people with obesity due to the extensive groundwork already established in other disease areas,” said lead author Casey Halpern, MD, resident in the Department of Neurosurgery of the Perelman School of Medicine at the University of Pennsylvania.
(Source: uphs.upenn.edu)