Our brain's response to the sight of food appears to be driven more by how low our blood sugar level is at the moment than our upbringing or genetics, researchers said at the annual meeting of the Society for the Study of Ingestive Behavior. "The finding suggest our brains have a way to override our genetic inheritance, upbringing and habits to respond to our immediate nutritional needs," said Dr. Ellen Schur, associate professor of medicine at the University of Washington.

In the study, Schur and UW Medicine colleagues at Harborview Medical Center, used brain scans to compare how appetite centers in the brains of identical twins responded to images of high- and low-calorie foods. The scans, called functional magnetic resonance imagers (fMRI), detect differences in the activity in different brain centers by measuring changes in blood flow

Studies of identical twins have shown that genetics and upbringing play a major role in a person's body weight regulation. In this study, the researchers wanted to determine what role inherited similarities in brain function had on appetite. In the study, the researchers hypothesized that because identical twins have nearly identical genetic inheritance their brain appetite centers would react similarly when the twins were shown the images of high- and low-calorie foods. To test their hypothesis, the researchers enrolled 21 pairs of identical (monozygotic) twins who had been raised together. The twins were first fed a standardized breakfast, and 3.5 hours later they underwent a baseline fMRI brain scan.

After the first scan, they were fed a filling meal of macaroni and cheese, calibrated to satiate their appetites. The twins then had a second fMRI during which they were shown photographs of non-fattening foods, such as fruits and vegetables, and fattening foods, such as pizza and french fries.

Changes in blood flow measured by the fMRI were used to assess how the activity of key appetite-regulating centers in their brains changed in response to the images. Afterwards, the twins were offered to eat what they would like from a buffet. How much they ate from the buffet was recorded.

At regular intervals during the experiment the twins were asked to rate their feelings of hunger, fullness and satisfaction, using a standardized scale, and blood samples were taken to measure blood glucose levels and levels of regulatory hormones, such as insulin, leptin and ghrelin.

The researchers found the twin pairs gave similar responses when asked to rate their appetite before and after meals, had similar hormonal responses, and even ate similar amounts from the buffet -- findings that suggest these responses were influenced by their shared upbringing and genetics. That did not seem to be the case with brain activation in response to the food images, however, when response tended to be greater in the twin with lower blood glucose levels.

The findings suggest that while genetics and upbringing play a big role in how much we weigh and how much we normally eat, our immediate response to food in the environment is driven by our bodies need for nutrition at the time, Schur said. "Just looking at pictures of high-calorie foods when we are hungry strongly engages parts of the brain that motivate us to eat." The study's findings might help explain why eating regular meals helps people keep their weight under control, she said.

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11 Reasons Why You're Not Losing Belly Fat

posted on 24 Jul 2014 18:45 by tawdryrainbow4632

Getting rid of your midriff bulge is significant for more than merely vanity's sake. Excessive abdominal fat--especially visceral fat, the sort that surrounds your organs and puffs your belly into a "beer gut"--is a predictor of heart disease, type 2 diabetes, insulin resistance, and some cancers. If diet and exercise have not done much to reduce your pooch your hormones, your age, and other genetic factors might be the reason why. Read on for 11 possible reasons why your belly fat will not budge.

Parents rate their corpulent children as 'very healthy'

posted on 23 Jul 2014 14:05 by tawdryrainbow4632

"Parents have a hard time shifting their kid's dietary and physical activity behaviors," said lead author Kyung Rhee, MD, and an assistant adjunct professor in the Department of Pediatrics. "Our study tells us what factors may be connected with a parent's motivation to help their child become more healthy."

The study relies on a survey of 202 parents whose kids were registered in a obesity clinic at the Hasbro Children's Hospital in Providence, Rhode Island in 2008 and 2009. The survey probed parents' readiness to take actionable measures to improve their child's eating habits and physical activity levels. The children ranged in age from 5 to 20 years old, having an average age of 13.8 years. More than two thirds were female, and nearly all (94 percent) were clinically classified as overweight.

Although most of the children have been referred to the obesity practice by a primary care provider and had metabolic markers of obesity, 31.4 percent of parents perceived their kid's health as excellent or very good and 28 percent didn't perceive their child's weight as a health concern.

Parents suggested a greater interest in helping their kid eat a healthy diet than supporting the pediatrician-recommended hour of daily physical activity.

Both diet and exercise are considered keys to good health, and a growing body of evidence suggests that these health habits are formed early in life.

Parents who had talked with their primary care physician about healthy eating strategies were more inclined to be in the "action phase of change" with their kid's diet. By comparison, parents who viewed their own battle as a health problem with weight were less likely to be addressing their kid's eating habits.

The researchers said income, instruction and race/ethnicity had no statistically significant impact on a parent's likelihood of making their kid dietary changes.

In regard to physical activity, researchers have no idea why parents seem to accentuate its role in good health, but the finding is consistent with other recent studies that suggest America's youth are mostly out-of-shape and sedentary, replacing playtime with "screen time."

Pros say one strategy to counteract the tendency may be to intervene early. Parents with children 14 or older were considerably less likely to want to become successful in helping their child acquire a physical dimension with their life than parents of younger children.

Poverty may also play a role in how much children move as parents with yearly incomes of less than $40,000 were also less likely to be actively engaged in ensuring their child got routine exercise.

The above story is based on materials provided by http://www.sciencedaily.com/releases/2014/07/140721142129.htm