Obesity risk is greater among men and women with fewer years of education and poorer economic circumstances and among women, but not men, of lower occupational status.
Women generally have a higher percentage of body fat than men, and there are indications that basal fat oxidation is lower in females as compared to men, thereby contributing to a higher fat storage in women.
Serotonin contributes to the regulation of food intake and appetite behavior. As body mass index (BMI) increases, the amount of serotonin synthesis decreases, presumably to indicate satiety at lower levels of food intake.
In men, this decrease occurs when men reach a BMI classifying them as “overweight,” whereas women do not experience this drop in serotonin synthesis until reaching a BMI classifying them as “obese.”
Tumor necrosis factor alpha (TNF-alpha) is expressed in fat cells and is possibly involved in the development of insulin resistance. One variant of the gene for TNF-alpha is associated with obesity in women, but not in men.
Obesity, especially abdominal obesity, is central to the metabolic syndrome and is strongly related to polycystic ovary syndrome (PCOS) in women. Obese women are particularly susceptible to diabetes and cardiovascular disease and have an increased risk of several major cancers in women, especially postmenopausal breast cancer and endometrial cancer.
Obese women who gain weight experience greater increases in blood pressure than their male counterparts.
Leptin
Leptin, a molecule produced by fat cells, is an important signal in the regulation of appetite and energy expenditure, and is thought to play a key role in the control of body weight. The level of leptin in the blood is correlated with BMI, and is far higher in women than men at every BMI level. This may be part of the reason why women are more likely than men to become overweight.
Testosterone appears to play a large role in the regulation of leptin levels in the blood; men with higher testosterone levels have lower leptin levels.
Leptin levels rise in girls and fall in boys at puberty. The sex difference in leptin levels appears to be due to the increase in testosterone in boys and the increase in fat mass in girls at this developmental stage.
Insulin resistance, which is thought to play a role in raising blood pressure, is correlated with blood leptin levels in men, but not in women.
Women who are pregnant with female fetuses experience significant increases in leptin levels during pregnancy, while women pregnant with male fetuses do not.
Exercise appears to reduce blood leptin concentrations in women but not in men.
Weight Loss
When losing weight, men are more likely to lose fat within the abdomen, whereas women are more likely to lose fat that resides just under the skin. Because of this difference, men experience greater declines in triglyceride levels and increases in HDL cholesterol (“good” cholesterol) levels compared to women losing the same amount of weight.
The prevalence of attempting to lose and maintain weight is 28.8 percent and 35.1 percent among men and 43.6 percent and 34.4 percent among women, respectively, and among those attempting to lose weight, only 21.5 percent of men and 19.4 percent of women reported using the recommended combination of eating fewer calories and engaging in at least 150 minutes of leisure-time physical activity per week.
Diet and exercise go
