Many say obesity is a result of over-eating and not exercising. When actually it is thought to be more than that. Researchers, who have been published in International Journal of Obesity, say that yes these are two big causes of obesity, but other causes are linked to America’s obesity epidemic.

1. Sleep debt. Getting too little sleep can increase body weight.
2. Pollution. Body weight is controlled by hormones. Today’s pollutants affect our hormones.
3. Air conditioning. You have the ability to burn calories when it is too hot or too cold in order to be comfortable. Today most people live and work in temperature-controlled homes and offices.
4. Decreased smoking. Smoking reduces weight. Americans are smoking less than what they used to.
5. Medicine. Many drugs (including contraceptives, steroid hormones, diabetes drugs, some antidepressants, and blood pressure medicines) can cause weight gain.
6. Population age and ethnicity. Middle-aged people and Hispanic-Americans tend to be more obese than young European-Americans. Americans are getting older and more Hispanic.
7. Older mothers. It has been proven that the older a woman is when she gives birth, the higher her child’s risk of obesity. American women are becoming moms later in life.
8. Ancestors’ environment. Some influences may go back two generations. Environmental changes that made a grandparent obese may visit obesity on the grandchildren.
9. Obesity linked to fertility. There is some evidence that obese people are more fertile than lean ones. If this is a genetic component, the percentage of obese people in the population should increase.
10. Unions of obese spouses. Obese women tend to marry obese men. If there are fewer thin people around – and if obesity has a genetic component – there will be still more obese people in the next generation.

Source: DeNoon, Daniel. “Obesity More Complex Than We Think?” Webmd.com http://www.webmd.com/content/article/124/115592.