Diet
The amount of energy intake relative to energy expenditure is the central reason for the development of obesity. However, diet composition also may be variably important in its pathogenesis.
Breastfeeding
Several recent papers have suggested that breast feeding may reduce the prevalence of obesity in later life.
Over eating
Voluntary overeating (repeated ingestion of energy exceeding daily energy needs) can increase body weight in normal weight men and women.
Dietary Fat Intake
Epidemiologic data suggest that a high fat diet is associated with obesity.
Dietary Carbohydrate and Fiber
When the consumption of sugar and body weight are examined there is usually an inverse relationship.
Frequency of Eating
The relationship between the frequency of meals and The development of obesity is unsettled.
Binge-Eating Disorder
Binge-eating disorder is a psychiatric illness characterized by uncontrolled episodes of eating, usually in the evening.
Night-Eating Syndrome
The night-eating syndrome is the consumption of atleast 25% (and usually >50%) of daily energy intake between the evening meal and the next morning
Dietary Calcium
Nearly 20 years ago, McCarron reported that there was a negative relationship between BMI and dietary calcium intake
Sedentary Lifestyle
A sedentary lifestyle lowers energy expenditure and promotes weight gain in both animals and humans.
Cessation of Smoking
Weight gain is very common when people stop smoking and is at least partly mediated by nicotine withdrawal. Weight gain of 1–2 kg in the first few weeks is often.
Drug-Induced Weight Gain
Several drugs can cause weight gain, including a variety of psychoactive agents and hormones. The degree of weight gain is generally not sufficient to cause true obesity
Growth Hormone Deficiency
Lean body mass is decreased and fat mass is increased in adults and children who are deficient in growth hormone
Polycystic Ovary Syndrome
Obesity, particularly central obesity, is common in this syndrome.
Hypothyroidism
Patients with hypothyroidism frequently gain weight because of a generalized slowing of metabolic activity. Some of this gain is fat. However, the weight gain is usually modest, and marked obesity is uncommon. Hypothyroidism is common, particularly in older women.