Originally Answered: Diabetes?!?
Yes, genetics can contribute to diabetes, but this is typically the diabetes type I that is affected by this. The pancreas does produce insulin, but in response to high blood sugars. The resistance to insulin is not genetic, it is when the insulin receptor cells found in every cell in the body gets tired of an overload of glucose in the blood. Eating sugar, high carb diets, etc. cause the blood sugar level to rise dramatically and then the pancreas secretes insulin to open the cellular "doors" to allow the glucose in to generate energy. We were never designed to eat refined sugars, only nutrient dense carbs that do not generate high insulin responses. When this happens, the alpha cells in the pancreas produce glucagon that goes to the liver where the gluclose is made into glycogen for storage. When a big insulin spike happens from a lot of sugar (glucose), the blood sugar is driven down hard by the action of the glucagon. Since our genetics have only changed about 0.1% in 12,000 years, we still respond like our ancestors. A very high insulin and glucagon response meant that we were in a state of "flight or fight" and the body needed to generate muscle power quickly, so this is why the adrenal glands then secrete cortisol (the stress hormone) to take care of this stressed situation.
It is this stressed situation and the constant spikes and drops in insulin, glucagon, and cortisol production that makes the insulin receptor cells in the body's cells to become fatigued and then resistant to insulin; this is Diabetes type II.
One other cause has been found by the University of California at Irvine and the University of Pennsylvania. That is a nano bacteria found in cooked foods that does not show up in lab tests and attacks the heart and it's arteries, pancreas, and kidneys; resulting in heart disease, diabetes, and kidney failure. This bacteria is normally killed by stomach acid, but taking antacids, eating the SAD diet (standard American diet), along with age, reduces the stomach acid content and allows free reign of this bacteria in the body.
If genetics were the reason for diabetes, we would have had the same number of cases years ago, but it is very evident that this is just another agenda driven argument of the food industry to allow them to continue to sell junk, not good science.
Additionally, any chemicals that attack the pancreas or liver can wreak havoc with the endocrine system and because it is a system of complex relationships, it's very easy to see why so many people are becoming diabetic.
The most recent statistics show that any child born after the year 2,000, 35% will get diabetes if caucasion, 50% if black, and 62% of ALL Latino women will have diabetes in their lifetime. Is it no wonder America now ranks 45th in longevity. 44 countries in the world have people living longer than Americans. 106,000 people died last year in hospitals taking Legally prescribed drugs prescribed by doctors for the particular illness the drug was designed to cure. And we fret over 1,000 soldiers that died last year in Iraq, as we should. Is our WAR ON DRUGS aimed at the right people? Only 10,000 to 20,000 died of illegal drugs on the street.
Anyone can get diabetes. The reason many fat people get it is because the same problem causing the diabetes is causing them to get fat, endocrine problems as described above.