Ch 9 Eating Disorder

Obesity:

causes structural and functional changes in the brain, including reduced gray matter volume, thinner cortex regions, and impaired white matter integrity. These brain alterations affect behaviors such as decision-making, impulsivity, and cognitive performance

Influence on obesity:

mental health, depression increased the probability of obesity, and that obesity increased the probability of depression. Adults gained about a pound per year, whereas the average for everyone else was about 8/10 of a pound

Environmental Influence on obesity:

the children of obese mothers are more likely than average to become obese themselves. That observation is consistent with both genetic and environmental explanations

Types of heritability for obesity:

Syndromal, Monogenic, and Polygenic

Syndromal obesity:

when genes cause a medical problem that includes obesity

Prader-Willi syndrome:

marked by mild cognitive disabilities, short stature, and obesity, with of course variation among individuals. People with this syndrome have blood levels of ghrelin four to five times higher than average resulting in overeating and still produce high ghrelin levels suggests that their problem relates to an inability to turn off ghrelin release

Monogenic obesity:

occurs when a single gene causes obesity without other physical or mental abnormalities. The most common type of monogenetic obesity comes from a mutation in the gene for the melanocortin receptor (important for satiety)

Polygenic obesity:

relates to many genes that slightly or moderately increase the probability of obesity. The most influential common gene is known as the FTO gene, which exists in many variants. Variations in the FTO gene do not always lead to obesity, but they increase the probability. Researchers have identified many other genetic variants that increase or decrease the probability of obesity

Native American Pima of Arizona and Mexico:

Diet consisted mostly of desert plants that ripen in the brief rainy season. They evolved a strategy of eating all they could when food was available, because it would have to carry them through periods of scarcity. They also evolved a tendency to conserve energy by limiting their activity.

Changes in diet for weight loss:

Many psychologists recommend small changes in diet (“eat a little less than usual”) on the expectation that more people will stick to this diet.

Weight loss:

Exercise is important, and it need not be strenuous, but it needs to be consistent, such as a long brisk walk on most days.

high-fructose corn syrup:

American companies began sweetening beverages with instead of sucrose. It is sweeter than sucrose, and the hope was that people could satisfy their craving for sweets with fewer calories. Since then, obesity became more common, not less.

Weight-loss drugs:

the FDA approved semaglutide (WegovyTM), which binds to brain receptors sensitive to glucagon-like peptide 1 (GLP-1).

Semaglutide:

with a program of exercise and a low-calorie diet led to a mean loss of 16 percent of body weight, with side effects that most people found tolerable

GLP-1:

increases activity in the satiety areas of the hypothalamus

Gastric bypass surgery:

Part of the stomach is sewed off so that food cannot enter. Remember that stomach distension is a major contributor to satiety. By decreasing stomach size, the surgery makes it possible for a smaller meal to produce satiety.

Why are over-the-counter weight-loss supplements risky

They often contain unlisted, untested, or high-dose stimulants and pharmaceuticals that can cause cardiovascular damage, organ toxicity, and severe mental health issues. T

Bulimia nervosa:

a condition in which people alternate between strict dieting and binges of overeating. Many, but not all, induce themselves to vomit, engaging in bingeing and purging.

the prevalence of bulimia:

about 1 percent of women and 0.1 percent of men. A major contributor to this problem is the cultural pressure on people, especially women, to be thin.

Bulimia nervosa culturally:

recorded only in cultures with a strong western influence, and cases are known where it began to occur after the introduction of American movies and television programs

bulimia biochemical abnormalities:

increased production of ghrelin, a hormone associated with increased appetite. The result of the binges and purges, rather than a cause. After therapy that decreases the symptoms of bulimia, the body chemicals return toward normal levels.

How bulimia resembles drug addiction:

Eating tasty foods activates the same brain areas as addictive drugs, such as the nucleus accumbens. Drug addicts who cannot get drugs sometimes overeat instead, and food-deprived people or animals become more likely than others to use drugs

Anorexia nervosa:

characterized by a refusal to eat enough to maintain a healthy body weight. Express an exaggerated fear of growing fat AND exercise soften.

Anorexia statistics:

more common among females than males, and that the onset is usually in the teenage years.