填空题 Being obese is more than being 1 . To determine if someone is obese, doctors and other 2 professionals need to measure a person"s 3 and weight. People gain weight when the body takes in more 4 than it burns off. Some of your 5 tell your body how to metabolize food. Sometimes 6 can fuel obesity as well. One important factor in weight gain is a 7 lifestyle, as people are much less active today than they used to be in their spare time. According the World Health Organization, about 8 billion people in the world are overweight and at least 300 million of them are 9 , even though obesity is one of the 10 most 10 health risks. In the United States, women are slightly more at risk for becoming obese than men. Race and 11 also can be factors. Obesity makes a person feel tired and 12 , and is also associated with 13 problems such as 14 and sleep apnea. People who are obese are more likely to be 15 , which can start a vicious cycle. The keys to healthy weight are regular 16 and good 17 habits. You may also want to keep a food and activity 18 You might also want to consider attending a 19 group. Above all, surround yourself with 20 and family who can help you tackle these important changes in your life.