<prompt> True about obesitySeen mostly in femalesPrevalence decrease upto 40 years of ageNo genetic predispositionSmoking is a risk factor  <response>: Ans. is d i.e., Smoking is a risk factor Cessation of smoking Weight gain is very common when people stop smoking. This is thought to be mediated at least in pa by nicotine withdrawal, which is associated with increased food intake and reduced energy expenditure. Weight gain of 1 to 2 kg in the first two weeks is often followed by an additional 2 to 3 kg weight gain over the next four to five months. The average weight gain is 4 to 5 kg but can be much greater. Obesity is common in both men and women more common in women. Etiologic Classification of Obesity latrogenic causes Drugs that cause weight gain Hypothalamic surgery Dietary obesity Infant feeding practices Progressive hyperplastic obesity Frequency of eating High fat diets Overeating Neuroendocrine obesities Hypothalamic obesity Seasonal affective disorder Cushings syndrome Polycystic ovary syndrome Hypogonadism Growth hormone deficiency Pseudohypoparathyroidism Social and behavioral factors Socioeconomic status Ethnicity Psychological factors Restrained eaters Night eating syndrome Binge-eating Sedentary lifestyle Enforced inactivity post-operative Aging Genetic dysmorphic obesities Autosomal recessive traits Autosomal dominant traits X-linked traits Chromosomal abnormalities Other Low bih weight 