The underlying causes of severe obesity are not known. The one thing that is certain is that obesity is not simply a result of overeating. Individual genetics, medical conditions, environment, metabolic rate and eating disorders combine in variations to determine one's weight.
Science continues to search for answers. But until the disease is better understood the control of excess weight is something many people must work at for their entire lives. Below we discuss some of the leading factors that contribute to obesity.
Genetic Factors
Numerous scientific studies have established that hereditary dynamics play an important role in your tendency to gain weight.
If others in your family are obese, then you have a higher risk for obesity. A study in Canada looked at 12 sets of identical twins. Each twin consume 1000 extra calories a day for three weeks. All of the subjects in the study gained weight. But not all subjects gained the same amount of weight. The interesting thing, though, was that in each set of twins, one twin gained the same amount as the other.
Genetic research also shows that a number of processes don't work as well in obese people as they do in others. These include how fat is burned, metabolism, and feelings of hunger and fullness.
Metabolism
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 quite 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 lost.
Environmental Factors
If you have a genetic predisposition toward obesity, then the modern American lifestyle may make controlling weight more difficult. Fast food, long days sitting at a desk, and suburban neighborhoods that require cars all magnify hereditary factors such as metabolism and efficient fat storage.
Environmental factors: The most important environmental factor is lifestyle. Your eating habits and activity level are partly learned from the people around you. Overeating and sedentary habits (inactivity) are the most important risk factors for obesity.
Psychological Factors
Psychological factors may also influence eating habits. Many people eat in response to depression, hopelessness, anger, boredom, and many other reasons that have nothing to do with hunger. Feelings influence their eating habits, causing them to overeat. Over time, the association between an emotion and food can become firmly fixed.
In some unusual cases, obesity may be used as a defense mechanism because of the perceived social pressures related to being more physically desirable.
Numerous scientific studies have established that hereditary dynamics play an important role in your tendency to gain weight.
