Endocrine Community
Get answers. Share advice. Learn More

7 Primary Causes of Obesity

Some reasons why obesity become a weighty issue

Americans are gaining weight, and obesity has become a national health threat. We can’t place the problem purely on self-control. Why has obesity become such a weighty issue?

Your daily meals are like a bank account: you take in calories (income) and spend them on physical activity (expense). When you take in more calories than you burn, you have a positive energy balance. While this would be a good thing for your bank account, it may not be a good thing for your weight. Of course, it is not simply a matter of addition and subtraction, and some people gain weight more readily than others. Several factors come into play.

Why Are We Packing On the Pounds?
Changes in our society and eating habits have contributed to the increase in obesity.

We eat differently.

  • We consume too much sugar: 60% of adults drink at least 1 sugary drink a day.
  • Foods higher in sugar, salt, and fat are widely marketed and advertised.
  • It often costs more to eat healthy.
  • Some people—especially those in lower-income, minority, and rural areas—do not have ready access to stores that sell healthy, affordable foods (eg, vegetables and fruit).
  • Restaurants, fast-food chains, and vending machines often sell higher-calorie foods. School vending machines and cafeterias are no exception.
  • Portion sizes, especially of less-healthful foods and beverages, have gotten bigger.

We do not get enough physical activity.

  • Safe walking or biking routes may be limited, so we rely on our cars, even for short trips.
  • Recreation centers and parks may not be easily accessible.
  • Students do not get enough, or good enough, physical education.
  • Most chores are now mechanized—gas or electricity powers the machines we use.
  • Technology has made us sedentary.

We have become a nation of “couch potatoes.”

  • We spend too much time in front of a screen—a lot of time watching TV or in front of the computer—and this is especially true for children. Children between the ages of 8 and 18 years spend 7.5 hours each day engaging in entertainment media—TV, computers, cell phones, movies, and video games—and about 4.5 of these hours are devoted to watching TV.
  • Not only do these passive pursuits detract from time that could be spent on physical activity, we eat meals and have snacks around the TV, which does its share of promoting this habit through advertising of high-calorie, unhealthful foods.

Breastfeeding is stopped too soon.

  • Breastfeeding protects children from becoming obese. However, although 75% of mothers do breastfeed, just 13% of infants rely on breast milk alone after 6 months.

Other factors exist that are mostly out of our control.

Heredity plays a role.

  • Genetic conditions such as Prader-Willi syndrome, for example, are a direct cause of obesity.
  • Scientists believe that a combination of certain genes and behavior may be needed to trigger obesity. A person’s genetic makeup may make him or her susceptible to obesity, but other factors are required to complete the picture.



  • Some drugs (antidepressants, steroids, and diabetes medications, for example) can cause weight gain.

An individual’s behavior, socioeconomic status, culture, and environmental factors also contribute to overweight and obesity. In addition, hormones in the brain, the gastrointestinal tract, and in fat cells themselves influence his or her metabolism, eating habits, and, ultimately, weight.

Continue Reading
Obesity and Health Consequences