These early behaviors often persist throughout a lifetime. Food has many psychological meanings for us. For some people, food equals love. Happy events are usually celebrated by eating. We have increased access to all kinds of food, especially food high in calories and fast food.
Some people overeat if they're depressed.
A growing body of evidence links obesity to genetics. One source states that 50 percent to 75 percent of obesity may be explained by genetic influences. A protein called leptin now is known to control appetite. When leptin is insufficient, a feeling of satiety is not achieved, and overeating occurs. Another gene related to the breakdown of fat and the production of bodily heat has a receptor in adipose tissue.