Causes of Obesity

•    Diet: Food that is dense in energy typically contains excessive calories. Portion sizes have also increased resulting in overeating. Processed food that is high in simple carbohydrates is often cheaper than vegetables and fruits, forcing people to pick the unhealthy option.
•    Sedentary lifestyle: Advancement in technology has resulted in less labor intensive working conditions. Television viewing has a direct impact on the amount of physical activity in both children and adults.
•    Genetics: Polymorphism in the genes of a person controls the metabolism and appetite and makes the person more vulnerable to obesity if conditions are favorable. Obesity is part of conditions such as Bardet-Biedl syndrome, MOMO syndrome, Cohen syndrome and Prader-Willi syndrome.
•    Illnesses: Certain medical illnesses such as growth hormone deficiency, hypothyroidism, eating disorders and Cushing’s syndrome can cause obesity.
•    Social determinants: In developed countries there is more pressure to remain thin and at the same time it provides more opportunites to be physically fit. In countries that are undeveloped, there are more labor intensive jobs to be done and so a higher percentage of fat in the body works to their advantage.
•    Infectious agents: Although not proven, viral infections have been associated with obesity.
•    Slow metabolism: It is the muscle in the body that burns fat. Men have more muscle than women and also aging results in loss of muscle.
•    Medications: Weight gain is sometimes caused by medications such as steroids, insulin, atypical antipsychotics, sulfonylureas, antidepressants, thiazolidinediones, certain anticonvulsants, some  hormonal contraceptives and pizotifen.
•    Cessation of smoking: Smoking decreases appetite making weight gain one of the withdrawal symptoms.
•    Lack of sleep: Sleep deprivation increases appetite due to hormonal changes.