The most common risk factor for obesity is energy imbalance. Weight is a balance between the amount of energy or calories you get from food/drink and the energy you use. Calories taken in should be equal to the amount of energy your body uses doing ordinary things like breathing, digesting and being physically active (like exercising). If your body takes in the same amount of energy it uses, your weight stays the same. If your body uses more calories than you take in, you lose weight. If you bring in more calories than your body uses you gain weight and this leads to obesity.

Physical inactivity is another risk factor. There are many reasons why Americans are not physically active. People spend hours in front of televisions and computers when working or relaxing. People use cars instead of walking. Modern technology reduces physical work, which reduces the need to burn calories. Without physical activity, people don’t burn the calories they take in from food and drinks.

Our current environment also encourages obesity. Neighborhoods lack sidewalks and safe places for recreation. This makes it hard for people to become physically active. Hectic work schedules cause people to not take time for exercise.

Genetics can also be a factor in obesity. Bardet-Beild syndrome and Prader-Willi syndrome are genetic disorders that can lead to obesity. People with these disorders feel constantly hungry even after eating a full meal. Diseases such as Cushing’s disease (a disorder caused by high levels of the hormone cortisol) and some medications might cause a person to become overweight.

Other risk factors for obesity include:

• Emotional factors: Some people eat more when they are bored, angry or stressed, which causes weight gain.
• Smoking: Some people gain weight when they stop smoking because food often tastes and smells better. Also, nicotine raises the rate at which the body burns calories. When you stop smoking, you burn fewer calories.
• Age: You tend to lose muscle as you get older, especially if you are less active. Muscle loss can slow down the rate at which your body burns calories.
• Pregnancy: Women gain weight so that the baby can develop normally and get the proper nutrition. Some women have a hard time losing weight after giving birth.
• Lack of sleep: Studies show that the less people sleep, the more likely they are to be overweight or obese. People who sleep fewer hours prefer to eat foods that are higher in calories and carbohydrates. Hormones such as insulin (which controls sugar levels), ghrelin (which causes hunger) and leptin (which curbs hunger) are affected when one gets too little sleep.

To learn more:

Obesity: Risk Factors
(Mayo Clinic)

Lists risk factors that might lead to obesity .

https://www.mayoclinic.org/diseases-conditions/obesity/basics/risk-factors/
CON-20014834

What causes overweight and obesity?
(National Heart, Lung and Blood Institute)

Lists and describes causes of obesity.

https://www.nhlbi.nih.gov/health/health-topics/topics/obe/causes

next » Prevention

Written by: Maya Hollinshead B.A.
Reviewed by: Jeffrey G. Schultze, M.D.
Last Modified: Monday November 28, 2016 11:07 AM