The neuroscience of obesity is still in its infancy. Each week, we learn more about the intricate interplay between mind and body. Some of the conclusions of researchers are intuitive. Others are counterintuitive. Some results support the notion that obesity is dictated by genetic coding or lifestyle; other studies assert that obesity is an increasing problem for all mammals, independent of the species.
If you’re like me, you evaluate the expanding stream of information and glean whatever insights you can. Here is the latest harvest of research on what causes obesity:
Certain Foods May Be Addictive—Fact or Fiction? Kelly Brownell, professor in the Department of Psychology at Yale University and cofounder of the Rudd Center for Food Policy & Obesity, asserts that some foods are addictive and act on the brain very much like morphine, alcohol and nicotine. These views surfaced in an article in the Journal of Addiction Medicine, where the authors, including Brownell, assert that “the evidence for food's addictive properties is steadily growing. In addition to clinical and evolutionary plausibility, the possibility of addiction to food is supported by animal model research and increasingly by research with humans. Much as classic drugs of abuse hijack the brain, accumulating evidence with food suggests a similar impact, but with weaker effects.” Dr. Brownell predicts that the science of food addiction is going to explode onto the scene shortly because numerous studies are generating compelling evidence.
Greedy Genes May Doom Diets: A specific gene may explain why some individuals fail to lose weight, despite conscious efforts to eat less. Studies conducted in England have shown that 14 percent of Britons carry two rouge copies of FTO, the gene linked with obesity. For individuals carrying one rouge gene, the risk of obesity is increased by 30 percent; for those who carry two rouge genes, the risk is increased by 70 percent.
Increased Weight Linked to Heightened Ability to Smell Food: Scientists in England have found that overweight and obese individuals have a better sense of smell than others do—but only when it comes to sniffing out food. When nonfood scents are involved, the overweight and obese individuals could not smell as well as their counterparts could. Scientists theorize that an enhanced sense of smell specific to food may make it more difficult for individuals to resist overeating and may contribute to surplus pounds.
Leptin Hormone Linked to Adult-Onset Obesity: Researchers at the University of Arkansas For Medical Sciences have been studying leptin in the pituitary gland to understand the hormone’s function. Based on their findings, researchers assert that leptin plays a significant role in adult-onset obesity. When the leptin receptor gene is removed from mice, the mice become obese upon reaching adulthood. Prior studies focused on leptin’s role as an appetite suppressant. In contrast, this latest study demonstrates how leptin receptors in the pituitary gland work with growth hormone cells to break down fat. When the leptin receptor is removed, obesity results.
Men, Mice and Other Species Are Getting Heavier: The obesity epidemic has been attributed to a number of factors, such as a sedentary society, a lack of proper nutrition education, the introduction of processed foods, the supersizing of portions and so on. Yet those explanations do not apply to other mammals, even those found in the wild, who are getting heavier. The implication is that the issue of obesity is even more complex than previously thought. In addition to known changes in our lifestyle, such as computers, television and energy-saving innovations, could invisible factors be making humans—and other mammals—fat? Are infections, chemical pollution or global warming involved in this complex process? Currently, no answer is obvious.
Obesity is a major health problem, not only in the United States but in developed countries around the world. Understanding the brain’s role in response to hormones and other factors will take on new urgency. With so much at stake, we can predict that scientists will explore the ways in which the brain influences our desire to eat.
Although there is no cure on the horizon, scientists are moving closer to understanding how and why people become obese. Almost daily, we learn more about the link between obesity and medical conditions, such as diabetes, heart disease, stroke and certain cancers. And before long, we hope to see safer interventions for individuals whose lives depend upon reversing obesity. Best of all, we anticipate the day when scientists will help us find a way to overcome genetic coding and environmental impacts so that you and I can enjoy the health and well-being we seek.