Underlying Causes of Obesity

The underlying causes of obesity are multiple and complex. It is not simply a result of overeating. Research has shown that in many cases morbid obesity has a genetic basis. Studies have also demonstrated that once the problem is established, traditional countermeasures such as dieting and exercise often fail to provide long–term improvement. Science continues to search for answers. However, until the disease is better understood, the control of excess weight is something patients must continue to work at their entire lives. None of the current interventions – including weight loss surgery – should be viewed as a cure. All are simply attempts to reduce the effects of obesity and alleviate its serious physical, emotional and social consequences.

Causes of obesity are multiple and complex:

Genetic Factors

Genes often play an important role in an individual’s tendency to gain weight beyond what is physiologically necessary. It is probable that a number of different genes are involved. Just as some genes determine eye color or height, others likely affect our appetite, our ability to feel full or satisfied, our metabolism, our fat-storing ability, and even our levels of physical activity.

Environmental Factors

It is clear that environmental and genetic factors are 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, and urban landscapes that discourage walking all tend to magnify the effects of genetically influenced factors such as metabolism. 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.


Weight gain and loss used to be viewed simply as 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. However, we know now that the process isn’t so simple. Obesity researchers now talk about a mechanism they call the “set point.” It’s a sort of thermostat in the brain that makes people resistant to weight gain or loss. Any attempt to override the set point by drastically cutting calorie intake causes the brain to respond by lowering metabolism and slowing activity. Weight initially lost is then gained back.

Weight loss surgery is not a cure for eating disorders. Certain medical conditions, such as hypothyroidism, can also trigger weight gain. That’s why it’s important that you work with your doctor to make sure you do not have a condition that should be treated with medication or counseling.