question: What causes Obesity?: Taking in more calories than your body burns can lead to obesity. This is because the body stores unused calories as fat. Obesity can be caused by:  - Eating more food than your body can use  - Drinking too much alcohol  - Not getting enough exercise    Many obese people who lose large amounts of weight and gain it back think it is their fault. They blame themselves for not having the willpower to keep the weight off. Many people regain more weight than they lost.  Today, we know that biology is a big reason why some people cannot keep the weight off. Some people who live in the same place and eat the same foods become obese, while others do not. Our bodies have a complex system to keep our weight at a healthy level. In some people, this system does not work normally.   The way we eat when we are children can affect the way we eat as adults.   The way we eat over many years becomes a habit. It affects what we eat, when we eat, and how much we eat.   We may feel that we are surrounded by things that make it easy to overeat and hard to stay active.   - Many people feel they do not have time to plan and make healthy meals.  - More people today work desk jobs compared to more active jobs in the past.  - People with little free time may have less time to exercise.    The term eating disorder means a group of medical conditions that have an unhealthy focus on eating, dieting, losing or gaining weight, and body image. A person may be obese, follow an unhealthy diet, and have an eating disorder all at the same time.  Sometimes, medical problems or treatments cause weight gain, including:  - Underactive thyroid (hypothyroidism)  - Medicines such as birth control pills, antidepressants, and antipsychotics    Other things that can cause weight gain are:  - Quitting smoking. Many people who quit smoking gain 4 to 10 pounds in the first 6 months after quitting.  - Stress, anxiety, feeling sad, or not sleeping well  - Menopause. Women may gain 12 to 15 pounds during menopause.  - Pregnancy. Women may not lose the weight they gained during pregnancy.