Risk Factors for Obesity

At a glance

Obesity is a complex and costly chronic disease influenced by many factors. These factors include health behaviors, stress, health conditions and medications, genes, and people's environment. Knowing the risk factors can help individuals and communities take steps to prevent and reduce obesity.

Health behaviors

Certain health behaviors can contribute to excess weight gain and are risk factors for obesity:

• Lack of physical activity.
• Unhealthy eating patterns such as:
  • Too many highly processed foods or added sugars, including too many sugar-sweetened beverages.
  • Too little fiber and fruits and vegetables.
• Not enough sleep or poor quality sleep.
• Too much TV, computer, video games, and other screen time.

Stress

Long-term stress can affect your brain and trigger your body to make high levels of hormones, such as cortisol. These hormones help regulate energy balances and hunger urges. High levels of these hormones can increase your appetite and promote cravings for foods that are high in fats and added sugars.1

Health conditions and medications

Some health conditions may lead to excess weight gain, obesity, or insulin resistance. These conditions include Cushing syndrome, polycystic ovary syndrome, or underactive thyroid.

Some medications may also cause weight gain by disrupting the brain's signals for hunger or through other mechanisms. These medications can include:

• Psychiatric medications, such as antipsychotics and antidepressants.
• Steroids.
• Certain types of hormonal birth control, such as progestins.
• Anti-seizure or mood-stabilizing drugs.
• Certain blood pressure and diabetes medications.

Genes

In specific, rare, single-gene disorders, genes can directly cause obesity. Examples of these disorders are Bardet-Biedl syndrome and Prader-Willi syndrome.

It is more common for multiple genes to be responsible for a person's feelings of hunger, sense of fullness, and metabolism.2

Systems and environment

Health is influenced by the conditions in which people live, learn, work, and play. Health can also be influenced by forces and policies that shape these conditions. These factors affect a person's ability to make healthy choices and influence their risk of gaining excess weight and developing obesity.

Examples include:

• Access to healthy, affordable foods and beverages.
• Access to safe places for physical activity.
• Community design to support activity-friendly routes to everyday destinations.
• Supportive childcare and school environments.
• Access to high-quality health care services.
• Safe housing and transportation.
• Economic stability.

Also, some chemicals in the environment can disrupt how our bodies work and cause excess weight gain. Understanding these factors and how we can use that knowledge to improve our health is ongoing.