A condition of being severely overweight, or obese. The term "obesity" more frequently is used for this condition in the U.S. where obesity is usually defined by measuring a person's body mass index (BMI). There also is a measurement of body fat used by some researchers known as the body adiposity index (BAI). Unlike the BMI, weight is not taken to account in the BAI, which is based on a person's height and hip circumference. Obvious reasons for weight gain are taking in more calories than usual or reducing the amount of physical activity in your life. However, some people seem to gain weight even when they are eating and exercising the same as always. Let's look deeper at possible reasons for weight gain. If you're not sleeping, you have more chances to indulge in late-night snacking. This is obvious. However, there's another reason lack of sleep might be adding on the pounds: biochemical changes in your body resulting from sleep deprivation can make you hungrier and leave you feeling less full after eating. Cortisol, the so-called "stress hormone," increases in our body when we're stressed out. This hormone, in turn, increases our appetite. Add to that the tendency to reach for comfort foods at times of stress, and you have a perfect opportunity for weight gain. Adiposity may be a complicated unwellness involving associate excessive quantity of body fat. fleshiness is not only a cosmetic concern. it's a medical drawback that will increase your risk of different diseases and health issues, like cardiovascular disease, diabetes, high pressure level and sure cancers.