There may be some truth to awful comments such as, "Well, she's big because she comes from big stock." Generally, we tend to inherit the same tendencies for metabolic rates, body frames, and other related body functions from our parents.
Everyone is different. We all burn calories at different rates, with different results. To control our weight, we need to understand and accommodate our unique metabolic rate.
Taken from
http://www.mymedicallearningcenter.com/Is_Meta bolism_Inherited_And_If_So,_Can_It_Be_Changed. html