Because 100 pounds of female skinny and 500 pounds of female fat compared to the female fat is several times the female skinny, big body, and solid. Female skinny person is more petite, the strength is certainly not as strong as female fat person, if the two confrontation, the skinny person should not be able to beat the fat person, so 500 pounds female fat person is more powerful.
Obesity is a group of common metabolic syndrome. When the human body to eat more calories than the consumption of calories, excess calories in the form of fat stored in the body, the amount of more than the normal physiological needs, and up to a certain value when it evolved into obesity.