Weight gain is a multifactorial condition resulting from a combination of genetic and familial predispositions, along with numerous environmental and behavioral factors. These factors include educational level, lifestyle choices, professional conditions, age, gender, eating speed, food preferences (especially consumption of processed and fast food), alcohol consumption, marital status, significant life events such as divorce or job changes, sociocultural status, quitting smoking, psychological factors, and, in women, menstrual cycle irregularities and the onset of menopause.