The reasons for obesity are multiple and complex. Despite conventional wisdom, it is not simply a result of overeating. Research has shown that in many cases, the significant underlying cause of morbid obesity is genetic. Studies have demonstrated that once the problem is established, efforts such as dieting and exercise programs have a limited ability to provide effective long-term relief.
Science continues to search for answers but, until the disease is better understood, the control of excess weight is something patients must work at for their entire lives. That is why it is very important to understand that all current medical interventions, including the Lap Band, Gastric Sleeve and Gastric Bypass procedures should not be considered medical cures. Rather, they are attempts to reduce the effects of excessive weight and alleviate the serious physical, emotional and social consequences of the disease.
The underlying causes of severe obesity are not known. There are many factors that contribute to the development of obesity including genetic, hereditary, metabolic, environmental, and eating disorders. There are also certain medical conditions that may result in some special type of obesity, such as the long term intake of steroids and some diseases such as hypothyroidism and hyper-adrenalism.
Numerous scientific studies have established that your genes play an important role in your tendency towards excess weight gain. The body weights of adopted children show no correlation with the body weights of their adoptive parents, who feed them and teach them how to eat. However, their weight does have an 80 percent correlation with their genetic parents, whom they have never met. As well, identical twins with identical genes, show a much higher similarity of body weights than do fraternal twins.
Certain groups of people, such as the Pima Indian tribe in Arizona and the growing Mexican-American population have shown a very high incidence of severe obesity. They also have significantly higher rates of diabetes and heart disease than other ethnic groups.
We probably have a number of genes directly related to weight. Just as some genes determine eye color or height, others can affect the appetite by increasing the amount of secretion of the Ghrelin Factor by the stomach, or the ability to feel full, satisfied, or have an early age-related change in metabolism. Our fat-storing ability, and our natural activity levels may even be affected by some predetermined gene.
Environmental and genetic factors are obviously closely intertwined. If you have a genetic predisposition toward obesity, then the modern American lifestyle and environment may make controlling weight more difficult. Fast food, long days sitting at a desk or in front of a TV screen or monitor, and suburban neighborhoods that require cars all magnify hereditary factors such as metabolism and efficient fat storage. For those suffering from morbid obesity, anything less than a total change in environment usually results in failure to reach and maintain a healthy body weight.
We used to think of weight gain or loss as only a function of calories ingested and then burned. Take in more calories than you burn, gain weight; burn more calories than you ingest, lose weight. But now we know the equation isn’t that simple. Obesity researchers now talk about a theory called the “set point,” a sort of Thermostat in the brain that makes people resistant to either weight gain or loss. If you try to override the set point by drastically cutting your calorie intake, your brain responds by lowering metabolism and slowing activity. You then gain back any weight you’ve lost.
Eating Disorders & Medical Conditions
Weight loss surgery is not a cure for eating disorders. And there are medical conditions, such as hypothyroidism, that can also cause weight gain. That’s why it’s important that you work along with your doctor to find out whether you have any conditions that should be treated with medication and counseling.
Arturo Rodriguez, MD