Weight gain and obesity are caused by consuming more calories than the body needs most commonly by eating a diet high in fat and calories, being sedentary or both. However, the imbalance between calories consumed and calories burned can also be caused by a number of different obesity-related factors, including genetic, hormonal, behavioral, environmental and even cultural. It is important to remember that obesity is not always simply a behavioral issue. In fact, endocrine researchers are on the forefront of medical research into the mechanisms of metabolism, appetite and satiety and their connection to obesity. For instance, genetic traits, the way a body expends energy (metabolism), hormones that affect the way calories are processed (hyperthyroidism), and other organ systems in the body can all affect appetite. Eating disorders, metabolic syndrome, behavioral issues and an individual’s environment and culture may also affect the development of
obesity. For this reason physicians consider many factors when assessing obesity.
The above information thankfully comes from the obesityinamerica.com at the following
link.