Obesity rates are increasing worldwide, associated with excess acute and chronic disease risk. In most countries, obesity rates among women exceed rates in men, particularly during the post menopausal years. Many factors affect body weight and appetite, including age, metabolic rate, physical activity level, stress, cultural factors, socioeconomic status, health status and health literacy, diet composition, attitudes, and beliefs. Gender affects appetite and body weight indirectly by altering factors contributing to food choice. However, there is emerging evidence that gender affects appetite and body weight directly, altering the physiological control systems regulating appetite. The follicular menstrual cycle phase (estrogen-rich) is associated with relative suppression of appetite. Lower estrogen levels are associated with increased food intake, body weight gain, and altered body fat distribution in humans and animals. This paper reviews the linkages between estrogen and appetite regulation. While relationships among appetite, body weight, and gender-linked hormones are complex, research elucidating these interrelationships could lead to development of gender-specific treatment approaches for obesity and appetite dysregulation.