Hunger and Satiety

with gender identity issues have gender dysphoria because they have no distress. This can be seen in children and adults.

People with gender identity issues often make the decision to live as their preferred gender. They take transgender hormone therapy and sometimes have surgery to alter their genitals. They change their name, dress, and lives so it matches their true identity.

HUNGER AND SATIETY

Hunger is a natural drive to eat and is necessary for survival. There are biological mechanisms in place with regard to hunger but there are also social, economic, and cultural issues that play a strong role in the entire process of eating. Some of these influences will cause eating disorders, which are discussed at the end of this section.

The stomach contracts when a person isn t eating, leading to hunger pang. There are certain chemical messages that travel to the brain to begin the drive to eat. The same thing happens when the blood glucose level drops. After eating, the person feels sated or full. Eating behaviors discontinue and the hormone leptin is released, which is the satiety hormone. On the other hand is ghrelin, which is released by the GI tract in order to signal hunger.

Parts of the hindbrain and the hypothalamus regulate hunger. Hunger is initiated by hormones like ghrelin, which triggers eating. After eating, the individual is sated and leptin is released so there is no more drive to eat.

A person s body weight is partially genetically determined and partially based on the environment. The number of calories eaten and the number of calories consumed are part of the environmental input into body weight. Fat is made when there is an excess of calories eaten versus what is burned off. The metabolic rate is also part of this. Metabolic rates differ from person to person.

In general, body weight is relatively stable, with the weight remaining within a narrow range. This has led to the set-point theory, which indicates that every person has an ideal body weight, which cannot easily be changed. This ideal body weight is genetically predetermined. People who lose weight do not have a change in their metabolic weight.

Critics of this theory point to the many social and environmental influences on a person s weight.

Overweight and obesity refer to having a body mass index (BMI) that is greater than what is considered healthy. The body mass index is a calculated number based on a person s weight and height. A normal body mass index is 18.5 to 25. A BMI of between 25 and 29.9 is said to be overweight. A BMI between 30 and 39.9 is obese, while morbid obesity is a BMI above 40. The BMI is basically a good indicator of obesity but it doesn t tell the difference between fat and muscle so muscular people could be misconstrued as being obese. Figure 22 shows a BMI chart:

Figure 22.

There are several negative consequences for being overweight, including type 2 diabetes, colon cancer, infertility, arthritis, liver disease, stroke, sleep apnea, breast cancer, and heart disease. About a third of the US population is obese and about two-thirds of adults are overweight. Being overweight is also something seen in children. Socioeconomic status and one s physical environment play a role in getting to be overweight. It takes exercise and healthy food options to maintain weight, which is not always available in some communities.

Diet and exercise are important to losing weight. In those who cannot lose weight by themselves, bariatric or weight loss surgery is sometimes utilized. The surgery modifies the stomach and other parts of the GI tract in order to limit both the intake of food and absorption of food. It is more effective than non-surgical options for weight loss.