There is no doubt that genetics play a very large role in the chances of developing certain diseases. For example, a woman that has seen her mother, grandmother, aunts and sister develop breast cancer had a very high chance of developing breast cancer herself. Similarly, a male that has lost pretty much every male in his family from premature heart disease also is looking at a similar fate.
However, weight control most certainly can impact on this “fate in health”. For example, if every woman that developed breast cancer in the family example listed above was morbidly obese and the remaining person kept weight under control, is there a better chance of breast cancer not developing? Similarly, in the example of the male with a family history of heart disease, perhaps every male in the family had weight control problems that brought on the co-morbidities of diabetes, hypertension and high cholesterol, all of which will increase the chances of developing the heart disease.
Yes, genetics are heavily involved in increasing risks of a number of diseases but effective weight control may be very helpful in changing the “fate of health”.