Can Thinking You Are Fat Make You Fat?

Researchers have found that normal-weight teens who think they are fat are more likely to grow up to be fat.

“Perceiving themselves as fat even though they are not may actually cause normal-weight children to become overweight as adults,” said Koenraad Cuypers, a researcher at the Norwegian University of Science and Technology.

Cuypers and his colleagues at the Department of Public Health and General Practice in NTNU’s Faculty of Medicine examined the obesity problem from a new angle: Their research looked at the relationship between perceived weights and actual weights in a study of teenagers and young adults.

The researchers note there are many reasons why teens who think they are fat — even when they are not — become overweight as adults.

One explanation may be related to psychosocial stress, which can be associated with gaining weight around the waist, the researchers said.

“Another explanation may be that young people who see themselves as fat often change their eating habits by skipping meals, for example. Research has shown that dropping breakfast can lead to obesity,” Cuypers said, adding that following a diet that you cannot maintain over time also is counterproductive, since the body strives to maintain the weight you had before you started the diet.

The researchers used data from the health survey Young-HUNT1, which was conducted from 1995-1997 and included 1,196 normal-weight teenagers of both sexes. Participants were later followed up in the Young-HUNT3 study, from 2006-2008, when they were between 24 and 30 years old.

Half of the participants still had normal weights as adults. But among those who were overweight, the researchers found that 59 percent of the girls who had felt fat as a teen became overweight in adulthood, as measured using body mass index or BMI. If waist circumference was used as the measure of obesity, then the percentage of teens who initially perceived themselves as fat and later became overweight as adults was 78 percent.

In contrast, 31 percent of the girls who did not consider themselves fat during adolescence were found in the follow-upstudy to be overweight as measured using BMI. That number was 55 percent as measured by waist circumference.

Normal-weight teens who rated themselves as fat in the initial HUNT study had a BMI in the followup study that was on average 0.88 higher than those who did not. They were also on average 3.46 centimeters larger as measured around the waist.

The study also shows that normal-weight girls were more likely than boys to rate themselves as overweight: 22 percent of girls and 9 percent of the boys saw themselves as fat in the first HUNT survey.

One explanation for this gender difference may be that the media’s focus on looks increasingly targets girls rather than boys, the researchers claim.

“Girls thus experience more psychosocial stress to achieve the ideal body,” Cuypers said. “Society needs to move away from a focus on weight, and instead needs to emphasize healthy eating habits, such as eating regular and varied meals and eating breakfast. Good sleep habits are also an advantage. And by reducing the amount that teens are transported to and from school and recreational activities, teens might also be able to avoid getting a ‘commuter belly.’”

Cuypers said he believes that the relationship between a perception of being overweight and the development of overweight is something that school systems and society as a whole must address to reverse the trend and reduce problems associated with obesity.

“The weight norms for society must be changed so that young people have a more realistic view of what is normal,” he said. “In school you should talk to kids about what are normal body shapes, and show that all bodies are beautiful as they are. And, last but not least, the media must cease to emphasize the supermodel body as the perfect ideal, because it is not.”

Cuypers’ results were published in the Journal of Obesity.

Source: Norwegian University of Science and Technology

Memory Connections Change from Childhood to Adulthood

In a new area of study, researchers explore how brain mechanisms for memory retrieval differ between adults and children.

Neuroscientists from Wayne State University and the Massachusetts Institute of Technology have discovered that while the memory systems are the same in many ways, the aging process appears to impart important differences in how we learn and respond to education.

Noa Ofen, Ph.D., an assistant professor in WSU’s Institute of Gerontology and Department of Pediatrics, says that cognitive ability, including the ability to learn and remember new information, dramatically changes between childhood and adulthood.

This ability parallels with dramatic changes that occur in the structure and function of the brain during these periods.

In the study, Ofen and her collaborative team tested the development of neural foundations of memory from childhood to young adulthood.

Researchers did this by exposing participants to pictures of scenes and then showing them the same scenes mixed with new ones. They then and asked them to judge whether each picture was presented earlier.

Participants made retrieval judgments while researchers collected images of their brains with magnetic resonance imaging (MRI).

Using this method, the researchers were able to see how the brain remembers. “Our results suggest that cortical regions related to attentional or strategic control show the greatest developmental changes for memory retrieval,” said Ofen.

This finding suggests that older participants use the cortical regions of the brain to retrieve past memories more so than younger participants.

“We were interested to see whether there are changes in the connectivity of regions in the brain that support memory retrieval,” Ofen added.

“We found changes in connectivity of memory-related regions. In particular, the developmental change in connectivity between regions was profound even without a developmental change in the recruitment of those regions, suggesting that functional brain connectivity is an important aspect of developmental changes in the brain.”

Researchers say this study is unique as it is the first time that the development of connectivity within memory systems in the brain has been tested.

Findings suggest the brain continues to rearrange connections to achieve adult-like performance during development.

Future studies by Ofen and her research team will focus on modeling brain network connectivity, and applying these methods to study abnormal brain development.

The team’s findings are published in the Journal of Neuroscience.

Source: Wayne State University