Studies have shown that genetics can cause you to be obese. Certain genes can cause you to be able to carry more fat cells. This means that you are more likely to gain fat and it makes the fat harder to lose. Studies have also shown that genetics are NOT the only factor in weight gain, but it has shown to be a big influence. I think that if your parents are more prone to weight gain and have more fat cells in their body then you would also be more likely to gain weight and hold on to fat.