Experts continue to question the of obesity. As you might expect, the many theories focus on factors within the individual, as the enviwell as from ronment. When a definitive cause is identified and some interesting progress has been made toward that goal it will comprise an interplay of genetic, metabolic, psychological, and environmental factors. However, until a single all- inclusive discovery is made, if ever, it is safe to assume that obesity is a complex condition caused by a variety of factors. obese people gain excessive weight in a variety of ways and for a variety of reasons.