My mother always said that being overweight is a blessing because only the rich can afford to be fat. Having lived most of her life in a rural countryside in China, my mother never thought there could be other reasons why people are overweight. America is the richest country in the world, and obesity has become a major health concern. A person is considered obese if their body weight is 20% over the normal weight (1). With obesity on the rise, the health problems that come along with being overweight are major concern in most American households. Being obese carries with it the predisposition to get diabetes, heart disease, and many other serious illnesses (2). Our bodies have biological mechanisms that tell us when we are hungry and when we are full. Do obese people have a defect in their biological mechanisms that control their weight or are other issues, such as lifestyle and psychology, affecting their weight?
From a biological prospective, our body must have a way of telling us when we need to eat to ensure survival. People are usually aware of their hunger when their stomach starts making noises. These noises are stomach contractions, but this sign is not the most important indication of hunger (2). The feeling of hunger comes from the hypothalamus, which is responsible for maintaining our body weight by telling us to consume more or less calories in order to have a properly functioning body (4). The mechanism starts when blood glucose levels are low. Then the liver, which changes food into glucose, sends a signal to the lateral hypothalamus. In order to increase the blood glucose levels, the lateral hypothalamus activates the behavior that each individual has for finding and consuming food (2). Low levels of leptin, a hormone released by fat cells, when detected by the hypothalamus, have also been showed to generate the feeling of hunger (4).
The