You may have heard of a so-called "thrifty gene" hypothesis, in which the researchers believe that a gene can store fat more effectively. People who carry the gene may have insulin resistance, which encourages their bodies to store more fat. This pre-stored fat can be used later for maintaining the body, although it will trigger even more storage of fat. Therefore, people with this type of gene are in poor health. However, even if every member in your family is overweight, it does not mean that you must be overweight, too. We all can improve the internal environment in the body and cells by choosing healthy foods and lifestyles in order to change the expression of the gene.