Obesity is influenced by many factors both inside and outside of the
body. A person could be born with a tendency to put on weight. Just as
someone is born with a particular eye colour.
There is also the physiological aspect. When a person eats,
hormone signals from the stomach and gut are translated into
feelings of reduced hunger and increased satiety. This controls a
person's food intake.
During weight loss, the level of hormones can change in an
attempt to regain the lost weight. As a result, studies show that
only about one third of people successfully maintain their lost weight.
Many aspects of a person's general well-being, environment and
lifestyle can also cause weight gain. Where a person lives and the
culture that surrounds them can also influence the risk of developing obesity.
So, although many people with obesity believe they should be able
to manage their weight on their own, it is not that easy.