Causes of Obesity

In almost all cases the cause of obesity is over eating. Simple. Now the over eating can be driven by many factors. Family situations are often a driver but that is complex. There are obese family members in the same household as those of normal weight. There is the phenomenon of ethnic groups who have lived for many generations on low caloric diets suddenly being exposed to "regular" diets and becoming obese. Two cases are of merit.

One is the Native American tribes in the Southwest. High obesity and high Type 2 Diabetes. There seems to be a lowered set point in metabolism that when presented with "normal" diets they seem to horde calories. The second is an interesting example, say the Irish after the famine and they come to the US and face a "normal" diet and thus have the same effect, obesity and in turn Type 2 Diabetes.

Now along comes another reason, somewhat suspicious. Namely racial and ethnic subtypes. In Eureka they state:

Many Americans need extraordinary willpower to avoid becoming obese – or to slim down if they already weigh too much. For members of minority groups, maintaining a healthy weight can be that much harder according to new research led by Luis Rivera, an experimental social psychologist at Rutgers University-Newark. Rivera says it is common for minorities in the United States to endure negative stereotypes, pervasive messages that suggest those groups are inferior, and that these attitudes can prevent people from doing what is needed to care for their health. "When you are exposed to negative stereotypes, you may gravitate more toward unhealthy foods as opposed to healthy foods," explains Rivera, whose study appears in this summer's edition of the Journal of Social Issues. "You may have a less positive attitude toward watching your carbs or cutting back on fast food, and toward working out and exercising." 

This seems to be based upon shaky ground. The same effects as seen in Native Americans and Irish Famine immigrants seem to be a better explanation. Immigrants from Hispanic lands in Central and South America come from low caloric diets and heavy manual labor. When the come here they face higher caloric intakes socially. Thus like the other cases one can see a set point difference, one lasting a few generations.

One may ask if this is akin to the methylation arguments seen in the Dutch Famine cases. It most likely is not attitude but a new set point.