Obesity in general means too much of body fat. Obesity occurs due to various reasons like; eating high calorie food, lack of sleep, lack of exercise, medications and improper metabolism. Early puberty in girls is associated with obesity in adulthood, finds a study conducted at Imperial College London. The findings of the study are published in the International Journal of Obesity. Previous studies have shown that there is a strong link between the onset of puberty and a woman's body mass in adulthood.